xnu-792.2.4.tar.gz

[apple/xnu.git] / osfmk / ppc / vmachmon.c

/*
 * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*-----------------------------------------------------------------------
** vmachmon.c
**
** C routines that we are adding to the MacOS X kernel.
**
-----------------------------------------------------------------------*/

#include <mach/mach_types.h>
#include <mach/kern_return.h>
#include <mach/host_info.h>
#include <kern/kern_types.h>
#include <kern/kalloc.h>
#include <kern/host.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <ppc/exception.h>
#include <ppc/mappings.h>
#include <ppc/thread.h>
#include <vm/vm_kern.h>
#include <vm/vm_fault.h>

#include <ppc/vmachmon.h>
#include <ppc/lowglobals.h>

extern double FloatInit;
extern unsigned long QNaNbarbarian[4];

/*************************************************************************************
        Virtual Machine Monitor Internal Routines
**************************************************************************************/

/*-----------------------------------------------------------------------
** vmm_get_entry
**
** This function verifies and return a vmm context entry index
**
** Inputs:
**              act - pointer to current thread activation
**              index - index into vmm control table (this is a "one based" value)
**
** Outputs:
**              address of a vmmCntrlEntry or 0 if not found
-----------------------------------------------------------------------*/

static vmmCntrlEntry *vmm_get_entry(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlTable *CTable;
        vmmCntrlEntry *CEntry;

        index = index & vmmTInum;                                                               /* Clean up the index */

        if (act->machine.vmmControl == 0) return NULL;                  /* No control table means no vmm */
        if ((index - 1) >= kVmmMaxContexts) return NULL;                /* Index not in range */        

        CTable = act->machine.vmmControl;                                               /* Make the address a bit more convienient */
        CEntry = &CTable->vmmc[index - 1];                                              /* Point to the entry */
        
        if (!(CEntry->vmmFlags & vmmInUse)) return NULL;                /* See if the slot is actually in use */
        
        return CEntry;
}

/*-----------------------------------------------------------------------
** vmm_get_adsp
**
** This function verifies and returns the pmap for an address space.
** If there is none and the request is valid, a pmap will be created.
**
** Inputs:
**              act - pointer to current thread activation
**              index - index into vmm control table (this is a "one based" value)
**
** Outputs:
**              address of a pmap or 0 if not found or could no be created
**              Note that if there is no pmap for the address space it will be created.
-----------------------------------------------------------------------*/

static pmap_t vmm_get_adsp(thread_t act, vmm_thread_index_t index)
{
        pmap_t pmap;

        if (act->machine.vmmControl == 0) return NULL;                  /* No control table means no vmm */
        if ((index - 1) >= kVmmMaxContexts) return NULL;                /* Index not in range */        

        pmap = act->machine.vmmControl->vmmAdsp[index - 1];             /* Get the pmap */
        return (pmap);                                                                                  /*  and return it. */
}

/*-----------------------------------------------------------------------
** vmm_build_shadow_hash
**
** Allocate and initialize a shadow hash table.
**
** This function assumes that PAGE_SIZE is 4k-bytes.
**
-----------------------------------------------------------------------*/
static pmap_vmm_ext *vmm_build_shadow_hash(pmap_t pmap)
{
        pmap_vmm_ext   *ext;                                                                    /* VMM pmap extension we're building */
        ppnum_t                 extPP;                                                                  /* VMM pmap extension physical page number */
        kern_return_t   ret;                                                                    /* Return code from various calls */
        uint32_t                pages = GV_HPAGES;                                              /* Number of pages in the hash table */
        vm_offset_t             free = VMX_HPIDX_OFFSET;                                /* Offset into extension page of free area (128-byte aligned) */
        uint32_t                freeSize  = PAGE_SIZE - free;                   /* Number of free bytes in the extension page */
                                                                                                                        
        if ((pages * sizeof(addr64_t)) + (pages * sizeof(vm_offset_t)) > freeSize) {
                panic("vmm_build_shadow_hash: too little pmap_vmm_ext free space\n");
        }
        
        ret = kmem_alloc_wired(kernel_map, (vm_offset_t *)&ext, PAGE_SIZE);
                                                                                                                        /* Allocate a page-sized extension block */
        if (ret != KERN_SUCCESS) return (NULL);                                 /* Return NULL for failed allocate */
        bzero((char *)ext, PAGE_SIZE);                                                  /* Zero the entire extension block page */
        
        extPP = pmap_find_phys(kernel_pmap, (vm_offset_t)ext);
                                                                                                                        /* Get extension block's physical page number */
        if (!extPP) {                                                                                   /* This should not fail, but then again... */
                panic("vmm_build_shadow_hash: could not translate pmap_vmm_ext vaddr %08X\n", ext);
        }
        
        ext->vmxSalt         = (addr64_t)(vm_offset_t)ext ^ ptoa_64(extPP);
                                                                                                                        /* Set effective<->physical conversion salt */
        ext->vmxHostPmapPhys = (addr64_t)(vm_offset_t)pmap ^ pmap->pmapvr;
                                                                                                                        /* Set host pmap's physical address */
        ext->vmxHostPmap     = pmap;                                                    /* Set host pmap's effective address */
        ext->vmxHashPgIdx    = (addr64_t *)((vm_offset_t)ext + VMX_HPIDX_OFFSET);
                                                                                                                        /* Allocate physical index */
        ext->vmxHashPgList       = (vm_offset_t *)((vm_offset_t)ext + VMX_HPLIST_OFFSET);
                                                                                                                        /* Allocate page list */
        ext->vmxActiveBitmap = (vm_offset_t *)((vm_offset_t)ext + VMX_ACTMAP_OFFSET);
                                                                                                                        /* Allocate active mapping bitmap */
        
        /* The hash table is typically larger than a single page, but we don't require it to be in a
           contiguous virtual or physical chunk. So, we allocate it page by page, noting the effective and
           physical address of each page in vmxHashPgList and vmxHashPgIdx, respectively. */
        uint32_t        idx;
        for (idx = 0; idx < pages; idx++) {
                ret = kmem_alloc_wired(kernel_map, &ext->vmxHashPgList[idx], PAGE_SIZE);
                                                                                                                        /* Allocate a hash-table page */
                if (ret != KERN_SUCCESS) goto fail;                                     /* Allocation failed, exit through cleanup */
                bzero((char *)ext->vmxHashPgList[idx], PAGE_SIZE);      /* Zero the page */
                ext->vmxHashPgIdx[idx] = ptoa_64(pmap_find_phys(kernel_pmap, (addr64_t)ext->vmxHashPgList[idx]));
                                                                                                                        /* Put page's physical address into index */
                if (!ext->vmxHashPgIdx[idx]) {                                          /* Hash-table page's LRA failed */
                        panic("vmm_build_shadow_hash: could not translate hash-table vaddr %08X\n", ext->vmxHashPgList[idx]);
                }
                mapping_t *map = (mapping_t *)ext->vmxHashPgList[idx];
                uint32_t mapIdx;
                for (mapIdx = 0; mapIdx < GV_SLTS_PPG; mapIdx++) {      /* Iterate over mappings in this page */
                        map->mpFlags = (mpGuest | mpgFree);                             /* Mark guest type and free */
                        map = (mapping_t *)((char *)map + GV_SLOT_SZ);  /* Next slot-sized mapping */
                }
        }
        
        return (ext);                                                                                   /* Return newly-minted VMM pmap extension */
        
fail:
        for (idx = 0; idx < pages; idx++) {                                             /* De-allocate any pages we managed to allocate */
                if (ext->vmxHashPgList[idx]) {
                        kmem_free(kernel_map, ext->vmxHashPgList[idx], PAGE_SIZE);
                }
        }
        kmem_free(kernel_map, (vm_offset_t)ext, PAGE_SIZE);             /* Release the VMM pmap extension page */
        return (NULL);                                                                                  /* Return NULL for failure */
}


/*-----------------------------------------------------------------------
** vmm_release_shadow_hash
**
** Release shadow hash table and VMM extension block
**
-----------------------------------------------------------------------*/
static void vmm_release_shadow_hash(pmap_vmm_ext *ext)
{
        uint32_t                idx;

        for (idx = 0; idx < GV_HPAGES; idx++) {                                 /* Release the hash table page by page */
                kmem_free(kernel_map, ext->vmxHashPgList[idx], PAGE_SIZE);
        }

        kmem_free(kernel_map, (vm_offset_t)ext, PAGE_SIZE);             /* Release the VMM pmap extension page */
}

/*-----------------------------------------------------------------------
** vmm_activate_gsa
**
** Activate guest shadow assist
**
-----------------------------------------------------------------------*/
static kern_return_t vmm_activate_gsa(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlTable   *CTable = act->machine.vmmControl;              /* Get VMM control table */
        if (!CTable) {                                                                                  /* Caller guarantees that this will work */
                panic("vmm_activate_gsa: VMM control table not present; act = %08X, idx = %d\n",
                        act, index);
                return KERN_FAILURE;
        }
        vmmCntrlEntry   *CEntry = vmm_get_entry(act, index);    /* Get context from index */
        if (!CEntry) {                                                                                  /* Caller guarantees that this will work */
                panic("vmm_activate_gsa: Unexpected failure of vmm_get_entry; act = %08X, idx = %d\n",
                        act, index);
                return KERN_FAILURE;
        }

        pmap_t  hpmap = act->map->pmap;                                                 /* Get host pmap */
        pmap_t  gpmap = vmm_get_adsp(act, index);                               /* Get guest pmap */
        if (!gpmap) {                                                                                   /* Caller guarantees that this will work */
                panic("vmm_activate_gsa: Unexpected failure of vmm_get_adsp; act = %08X, idx = %d\n",
                        act, index);
                return KERN_FAILURE;
        }
        
        if (!hpmap->pmapVmmExt) {                                                               /* If there's no VMM extension for this host, create one */
                hpmap->pmapVmmExt = vmm_build_shadow_hash(hpmap);       /* Build VMM extension plus shadow hash and attach */
                if (hpmap->pmapVmmExt) {                                                        /* See if we succeeded */
                        hpmap->pmapVmmExtPhys = (addr64_t)(vm_offset_t)hpmap->pmapVmmExt ^ hpmap->pmapVmmExt->vmxSalt;
                                                                                                                        /* Get VMM extensions block physical address */
                } else {
                        return KERN_RESOURCE_SHORTAGE;                                  /* Not enough mojo to go */
                }
        }
        gpmap->pmapVmmExt = hpmap->pmapVmmExt;                                  /* Copy VMM extension block virtual address into guest */
        gpmap->pmapVmmExtPhys = hpmap->pmapVmmExtPhys;                  /*  and its physical address, too */
        gpmap->pmapFlags |= pmapVMgsaa;                                                 /* Enable GSA for this guest */
        CEntry->vmmXAFlgs |= vmmGSA;                                                    /* Show GSA active here, too */

        return KERN_SUCCESS;
}


/*-----------------------------------------------------------------------
** vmm_deactivate_gsa
**
** Deactivate guest shadow assist
**
-----------------------------------------------------------------------*/
static void vmm_deactivate_gsa(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry   *CEntry = vmm_get_entry(act, index);    /* Get context from index */
        if (!CEntry) {                                                                                  /* Caller guarantees that this will work */
                panic("vmm_deactivate_gsa: Unexpected failure of vmm_get_entry; act = %08X, idx = %d\n",
                        act, index);
                return KERN_FAILURE;
        }

        pmap_t  gpmap = vmm_get_adsp(act, index);                               /* Get guest pmap */
        if (!gpmap) {                                                                                   /* Caller guarantees that this will work */
                panic("vmm_deactivate_gsa: Unexpected failure of vmm_get_adsp; act = %08X, idx = %d\n",
                        act, index);
                return KERN_FAILURE;
        }
        
        gpmap->pmapFlags &= ~pmapVMgsaa;                                                /* Deactivate GSA for this guest */
        CEntry->vmmXAFlgs &= ~vmmGSA;                                                   /* Show GSA deactivated here, too */
}


/*-----------------------------------------------------------------------
** vmm_flush_context
**
** Flush specified guest context, purging all guest mappings and clearing
** the context page.
**
-----------------------------------------------------------------------*/
static void vmm_flush_context(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry           *CEntry;
        vmmCntrlTable           *CTable;
        vmm_state_page_t        *vks;
        vmm_version_t           version;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */
        if (!CEntry) {                                                                  /* Caller guarantees that this will work */
                panic("vmm_flush_context: Unexpected failure of vmm_get_entry; act = %08X, idx = %d\n",
                        act, index);
                return;
        }

        if(CEntry->vmmFacCtx.FPUsave) {                                 /* Is there any floating point context? */
                toss_live_fpu(&CEntry->vmmFacCtx);                      /* Get rid of any live context here */
                save_release((savearea *)CEntry->vmmFacCtx.FPUsave);    /* Release it */
        }

        if(CEntry->vmmFacCtx.VMXsave) {                                 /* Is there any vector context? */
                toss_live_vec(&CEntry->vmmFacCtx);                      /* Get rid of any live context here */
                save_release((savearea *)CEntry->vmmFacCtx.VMXsave);    /* Release it */
        }
        
        vmm_unmap_all_pages(act, index);                                /* Blow away all mappings for this context */

        CTable = act->machine.vmmControl;                               /* Get the control table address */
        CTable->vmmGFlags = CTable->vmmGFlags & ~vmmLastAdSp;   /* Make sure we don't try to automap into this */
        
        CEntry->vmmFlags &= vmmInUse;                                   /* Clear out all of the flags for this entry except in use */
        CEntry->vmmFacCtx.FPUsave = 0;                                  /* Clear facility context control */
        CEntry->vmmFacCtx.FPUlevel = 0;                                 /* Clear facility context control */
        CEntry->vmmFacCtx.FPUcpu = 0;                                   /* Clear facility context control */
        CEntry->vmmFacCtx.VMXsave = 0;                                  /* Clear facility context control */
        CEntry->vmmFacCtx.VMXlevel = 0;                                 /* Clear facility context control */
        CEntry->vmmFacCtx.VMXcpu = 0;                                   /* Clear facility context control */
        
        vks = CEntry->vmmContextKern;                                   /* Get address of the context page */
        version = vks->interface_version;                               /* Save the version code */
        bzero((char *)vks, 4096);                                               /* Clear all */

        vks->interface_version = version;                               /* Set our version code */
        vks->thread_index = index % vmmTInum;                   /* Tell the user the index for this virtual machine */
                
        return;                                                                                 /* Context is now flushed */
}


/*************************************************************************************
        Virtual Machine Monitor Exported Functionality
        
        The following routines are used to implement a quick-switch mechanism for
        virtual machines that need to execute within their own processor envinroment
        (including register and MMU state).
**************************************************************************************/

/*-----------------------------------------------------------------------
** vmm_get_version
**
** This function returns the current version of the virtual machine
** interface. It is divided into two portions. The top 16 bits
** represent the major version number, and the bottom 16 bits
** represent the minor version number. Clients using the Vmm
** functionality should make sure they are using a verison new
** enough for them.
**
** Inputs:
**              none
**
** Outputs:
**              32-bit number representing major/minor version of 
**                              the Vmm module
-----------------------------------------------------------------------*/

int vmm_get_version(struct savearea *save)
{
        save->save_r3 = kVmmCurrentVersion;             /* Return the version */
        return 1;
}


/*-----------------------------------------------------------------------
** Vmm_get_features
**
** This function returns a set of flags that represents the functionality
** supported by the current verison of the Vmm interface. Clients should
** use this to determine whether they can run on this system.
**
** Inputs:
**              none
**
** Outputs:
**              32-bit number representing functionality supported by this
**                              version of the Vmm module
-----------------------------------------------------------------------*/

int vmm_get_features(struct savearea *save)
{
        save->save_r3 = kVmmCurrentFeatures;            /* Return the features */
        if(getPerProc()->pf.Available & pf64Bit) {
                save->save_r3 &= ~kVmmFeature_LittleEndian;     /* No little endian here */
                save->save_r3 |= kVmmFeature_SixtyFourBit;      /* Set that we can do 64-bit */
        }
        return 1;
}


/*-----------------------------------------------------------------------
** vmm_max_addr
**
** This function returns the maximum addressable virtual address sported
**
** Outputs:
**              Returns max address
-----------------------------------------------------------------------*/

addr64_t vmm_max_addr(thread_t act) 
{
        return vm_max_address;                                                  /* Return the maximum address */
}

/*-----------------------------------------------------------------------
** vmm_get_XA
**
** This function retrieves the eXtended Architecture flags for the specifed VM.
** 
** We need to return the result in the return code rather than in the return parameters
** because we need an architecture independent format so the results are actually 
** usable by the host. For example, the return parameters for 64-bit are 8 bytes wide vs.
** 4 for 32-bit. 
** 
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**
** Outputs:
**              Return code is set to the XA flags.  If the index is invalid or the
**              context has not been created, we return 0.
-----------------------------------------------------------------------*/

unsigned int vmm_get_XA(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry           *CEntry;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return 0;                                   /* Either this isn't a vmm or the index is bogus */
        
        return CEntry->vmmXAFlgs;                                               /* Return the flags */
}

/*-----------------------------------------------------------------------
** vmm_init_context
**
** This function initializes an  emulation context. It allocates
** a new pmap (address space) and fills in the initial processor
** state within the specified structure. The structure, mapped
** into the client's logical address space, must be page-aligned.
**
** Inputs:
**              act - pointer to current thread activation
**              version - requested version of the Vmm interface (allowing
**                      future versions of the interface to change, but still
**                      support older clients)
**              vmm_user_state - pointer to a logical page within the
**                      client's address space
**
** Outputs:
**              kernel return code indicating success or failure
-----------------------------------------------------------------------*/

int vmm_init_context(struct savearea *save)
{

        thread_t                        act;
        vmm_version_t           version;
        vmm_state_page_t *      vmm_user_state;
        vmmCntrlTable           *CTable;
        vm_offset_t                     conkern;
        vmm_state_page_t *      vks;
        ppnum_t                         conphys;
        kern_return_t           ret;
        int                                     cvi, i;
    task_t                              task;
    thread_t                    fact, gact;

        vmm_user_state = CAST_DOWN(vmm_state_page_t *, save->save_r4);  /* Get the user address of the comm area */
        if ((unsigned int)vmm_user_state & (PAGE_SIZE - 1)) {   /* Make sure the comm area is page aligned */
                save->save_r3 = KERN_FAILURE;                   /* Return failure */
                return 1;
        }

        /* Make sure that the version requested is supported */
        version = save->save_r3;                                        /* Pick up passed in version */
        if (((version >> 16) < kVmmMinMajorVersion) || ((version >> 16) > (kVmmCurrentVersion >> 16))) {
                save->save_r3 = KERN_FAILURE;                   /* Return failure */
                return 1;
        }

        if((version & 0xFFFF) > kVmmCurMinorVersion) {  /* Check for valid minor */
                save->save_r3 = KERN_FAILURE;                   /* Return failure */
                return 1;
        }

        act = current_thread();                                         /* Pick up our activation */
        
        ml_set_interrupts_enabled(TRUE);                        /* This can take a bit of time so pass interruptions */
        
        task = current_task();                                          /* Figure out who we are */

        task_lock(task);                                                        /* Lock our task */

        fact = (thread_t)task->threads.next;    /* Get the first activation on task */
        gact = 0;                                                                       /* Pretend we didn't find it yet */

        for(i = 0; i < task->thread_count; i++) {       /* All of the activations */
                if(fact->machine.vmmControl) {                          /* Is this a virtual machine monitor? */
                        gact = fact;                                            /* Yeah... */
                        break;                                                          /* Bail the loop... */
                }
                fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
        }
        

/*
 *      We only allow one thread per task to be a virtual machine monitor right now.  This solves
 *      a number of potential problems that I can't put my finger on right now.
 *
 *      Utlimately, I think we want to move the controls and make all this task based instead of
 *      thread based.  That would allow an emulator architecture to spawn a kernel thread for each
 *      VM (if they want) rather than hand dispatch contexts.
 */

        if(gact && (gact != act)) {                                     /* Check if another thread is a vmm or trying to be */
                task_unlock(task);                                              /* Release task lock */
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                save->save_r3 = KERN_FAILURE;                   /* We must play alone... */
                return 1;
        }
        
        if(!gact) act->machine.vmmControl = (vmmCntrlTable *)1; /* Temporarily mark that we are the vmm thread */

        task_unlock(task);                                                      /* Safe to release now (because we've marked ourselves) */

        CTable = act->machine.vmmControl;                               /* Get the control table address */
        if ((unsigned int)CTable == 1) {                        /* If we are marked, try to allocate a new table, otherwise we have one */
                if(!(CTable = (vmmCntrlTable *)kalloc(sizeof(vmmCntrlTable)))) {        /* Get a fresh emulation control table */
                        act->machine.vmmControl = 0;                    /* Unmark us as vmm 'cause we failed */
                        ml_set_interrupts_enabled(FALSE);       /* Set back interruptions */
                        save->save_r3 = KERN_RESOURCE_SHORTAGE;         /* No storage... */
                        return 1;
                }
                
                bzero((void *)CTable, sizeof(vmmCntrlTable));   /* Clean it up */
                act->machine.vmmControl = CTable;                       /* Initialize the table anchor */
        }

        for(cvi = 0; cvi < kVmmMaxContexts; cvi++) {    /* Search to find a free slot */
                if(!(CTable->vmmc[cvi].vmmFlags & vmmInUse)) break;     /* Bail if we find an unused slot */
        }
        
        if(cvi >= kVmmMaxContexts) {                            /* Did we find one? */
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                save->save_r3 = KERN_RESOURCE_SHORTAGE; /* No empty slots... */ 
                return 1;
        }

        ret = vm_map_wire(                                                      /* Wire the virtual machine monitor's context area */
                act->map,
                (vm_offset_t)vmm_user_state,
                (vm_offset_t)vmm_user_state + PAGE_SIZE,
                VM_PROT_READ | VM_PROT_WRITE,
                FALSE);                                                                                                                 
                
        if (ret != KERN_SUCCESS)                                        /* The wire failed, return the code */
                goto return_in_shame;

        /* Map the vmm state into the kernel's address space. */
        conphys = pmap_find_phys(act->map->pmap, (addr64_t)((uintptr_t)vmm_user_state));

        /* Find a virtual address to use. */
        ret = kmem_alloc_pageable(kernel_map, &conkern, PAGE_SIZE);
        if (ret != KERN_SUCCESS) {                                      /* Did we find an address? */
                (void) vm_map_unwire(act->map,                  /* No, unwire the context area */
                        (vm_offset_t)vmm_user_state,
                        (vm_offset_t)vmm_user_state + PAGE_SIZE,
                        TRUE);
                goto return_in_shame;
        }
        
        /* Map it into the kernel's address space. */

        pmap_enter(kernel_pmap, conkern, conphys, 
                VM_PROT_READ | VM_PROT_WRITE, 
                VM_WIMG_USE_DEFAULT, TRUE);
        
        /* Clear the vmm state structure. */
        vks = (vmm_state_page_t *)conkern;
        bzero((char *)vks, PAGE_SIZE);
        
        
        /* We're home free now. Simply fill in the necessary info and return. */
        
        vks->interface_version = version;                       /* Set our version code */
        vks->thread_index = cvi + 1;                            /* Tell the user the index for this virtual machine */
        
        CTable->vmmc[cvi].vmmFlags = vmmInUse;          /* Mark the slot in use and make sure the rest are clear */
        CTable->vmmc[cvi].vmmContextKern = vks;         /* Remember the kernel address of comm area */
        CTable->vmmc[cvi].vmmContextPhys = conphys;     /* Remember the state page physical addr */
        CTable->vmmc[cvi].vmmContextUser = vmm_user_state;              /* Remember user address of comm area */
        
        CTable->vmmc[cvi].vmmFacCtx.FPUsave = 0;        /* Clear facility context control */
        CTable->vmmc[cvi].vmmFacCtx.FPUlevel = 0;       /* Clear facility context control */
        CTable->vmmc[cvi].vmmFacCtx.FPUcpu = 0;         /* Clear facility context control */
        CTable->vmmc[cvi].vmmFacCtx.VMXsave = 0;        /* Clear facility context control */
        CTable->vmmc[cvi].vmmFacCtx.VMXlevel = 0;       /* Clear facility context control */
        CTable->vmmc[cvi].vmmFacCtx.VMXcpu = 0;         /* Clear facility context control */
        CTable->vmmc[cvi].vmmFacCtx.facAct = act;       /* Point back to the activation */

        hw_atomic_add((int *)&saveanchor.savetarget, 2);        /* Account for the number of extra saveareas we think we might "need" */

        pmap_t hpmap = act->map->pmap;                                          /* Get host pmap */
        pmap_t gpmap = pmap_create(0);                                          /* Make a fresh guest pmap */
        if (gpmap) {                                                                            /* Did we succeed ? */
                CTable->vmmAdsp[cvi] = gpmap;                                   /* Remember guest pmap for new context */
                if (lowGlo.lgVMMforcedFeats & vmmGSA) {                 /* Forcing on guest shadow assist ? */
                        vmm_activate_gsa(act, cvi+1);                           /* Activate GSA */ 
                }
        } else {
                ret = KERN_RESOURCE_SHORTAGE;                                   /* We've failed to allocate a guest pmap */
                goto return_in_shame;                                                   /* Shame on us. */
        }

        if (!(hpmap->pmapFlags & pmapVMhost)) {                         /* Do this stuff if this is our first time hosting */
                hpmap->pmapFlags |= pmapVMhost;                                 /* We're now hosting */
        }
        
        ml_set_interrupts_enabled(FALSE);                       /* Set back interruptions */
        save->save_r3 = KERN_SUCCESS;                           /* Hip, hip, horay... */        
        return 1;

return_in_shame:
        if(!gact) kfree(CTable, sizeof(vmmCntrlTable)); /* Toss the table if we just allocated it */
        act->machine.vmmControl = 0;                                    /* Unmark us as vmm 'cause we failed */
        ml_set_interrupts_enabled(FALSE);                       /* Set back interruptions */
        save->save_r3 = ret;                                            /* Pass back return code... */  
        return 1;

}


/*-----------------------------------------------------------------------
** vmm_tear_down_context
**
** This function uninitializes an emulation context. It deallocates
** internal resources associated with the context block.
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**
** Outputs:
**              kernel return code indicating success or failure
**
** Strangeness note:
**              This call will also trash the address space with the same ID.  While this 
**              is really not too cool, we have to do it because we need to make
**              sure that old VMM users (not that we really have any) who depend upon 
**              the address space going away with the context still work the same.
-----------------------------------------------------------------------*/

kern_return_t vmm_tear_down_context(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry           *CEntry;
        vmmCntrlTable           *CTable;
        int                                     cvi;
        register savearea       *sv;

        CEntry = vmm_get_entry(act, index);                                     /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                        /* Either this isn't vmm thread or the index is bogus */

        ml_set_interrupts_enabled(TRUE);                                        /* This can take a bit of time so pass interruptions */

        hw_atomic_sub((int *)&saveanchor.savetarget, 2);        /* We don't need these extra saveareas anymore */

        if(CEntry->vmmFacCtx.FPUsave) {                                         /* Is there any floating point context? */
                toss_live_fpu(&CEntry->vmmFacCtx);                              /* Get rid of any live context here */
                save_release((savearea *)CEntry->vmmFacCtx.FPUsave);    /* Release it */
        }

        if(CEntry->vmmFacCtx.VMXsave) {                                         /* Is there any vector context? */
                toss_live_vec(&CEntry->vmmFacCtx);                              /* Get rid of any live context here */
                save_release((savearea *)CEntry->vmmFacCtx.VMXsave);    /* Release it */
        }
        
        CEntry->vmmPmap = 0;                                                            /* Remove this trace */
        pmap_t gpmap = act->machine.vmmControl->vmmAdsp[index - 1];
                                                                                                                /* Get context's guest pmap (if any) */
        if (gpmap) {                                                                            /* Check if there is an address space assigned here */
                if (gpmap->pmapFlags & pmapVMgsaa) {                    /* Handle guest shadow assist case specially */
                        hw_rem_all_gv(gpmap);                                           /* Remove all guest mappings from shadow hash table */
                } else {
                        mapping_remove(gpmap, 0xFFFFFFFFFFFFF000LL);/* Remove final page explicitly because we might have mapped it */  
                        pmap_remove(gpmap, 0, 0xFFFFFFFFFFFFF000LL);/* Remove all entries from this map */
                }
                pmap_destroy(gpmap);                                                    /* Toss the pmap for this context */
                act->machine.vmmControl->vmmAdsp[index - 1] = NULL;     /* Clean it up */
        }
        
        (void) vm_map_unwire(                                                   /* Unwire the user comm page */
                act->map,
                (vm_offset_t)CEntry->vmmContextUser,
                (vm_offset_t)CEntry->vmmContextUser + PAGE_SIZE,
                FALSE);
        
        kmem_free(kernel_map, (vm_offset_t)CEntry->vmmContextKern, PAGE_SIZE);  /* Remove kernel's view of the comm page */
        
        CTable = act->machine.vmmControl;                                       /* Get the control table address */
        CTable->vmmGFlags = CTable->vmmGFlags & ~vmmLastAdSp;   /* Make sure we don't try to automap into this */

        CEntry->vmmFlags = 0;                                                   /* Clear out all of the flags for this entry including in use */
        CEntry->vmmContextKern = 0;                                             /* Clear the kernel address of comm area */
        CEntry->vmmContextUser = 0;                                             /* Clear the user address of comm area */
        
        CEntry->vmmFacCtx.FPUsave = 0;                                  /* Clear facility context control */
        CEntry->vmmFacCtx.FPUlevel = 0;                                 /* Clear facility context control */
        CEntry->vmmFacCtx.FPUcpu = 0;                                   /* Clear facility context control */
        CEntry->vmmFacCtx.VMXsave = 0;                                  /* Clear facility context control */
        CEntry->vmmFacCtx.VMXlevel = 0;                                 /* Clear facility context control */
        CEntry->vmmFacCtx.VMXcpu = 0;                                   /* Clear facility context control */
        CEntry->vmmFacCtx.facAct = 0;                                   /* Clear facility context control */
        
        for(cvi = 0; cvi < kVmmMaxContexts; cvi++) {    /* Search to find a free slot */
                if(CTable->vmmc[cvi].vmmFlags & vmmInUse) {     /* Return if there are still some in use */
                        ml_set_interrupts_enabled(FALSE);               /* No more interruptions */
                        return KERN_SUCCESS;                                    /* Leave... */
                }
        }

/*
 *      When we have tossed the last context, toss any address spaces left over before releasing
 *      the VMM control block 
 */

        for(cvi = 1; cvi <= kVmmMaxContexts; cvi++) {   /* Look at all slots */
                if(!act->machine.vmmControl->vmmAdsp[index - 1]) continue;      /* Nothing to remove here */
                mapping_remove(act->machine.vmmControl->vmmAdsp[index - 1], 0xFFFFFFFFFFFFF000LL);      /* Remove final page explicitly because we might have mapped it */      
                pmap_remove(act->machine.vmmControl->vmmAdsp[index - 1], 0, 0xFFFFFFFFFFFFF000LL);      /* Remove all entries from this map */
                pmap_destroy(act->machine.vmmControl->vmmAdsp[index - 1]);      /* Toss the pmap for this context */
                act->machine.vmmControl->vmmAdsp[index - 1] = 0;        /* Clear just in case */
        }
        
        pmap_t pmap = act->map->pmap;                                   /* Get our pmap */
        if (pmap->pmapVmmExt) {                                                 /* Release any VMM pmap extension block and shadow hash table */
                vmm_release_shadow_hash(pmap->pmapVmmExt);      /* Release extension block and shadow hash table */
                pmap->pmapVmmExt     = 0;                                       /* Forget extension block */
                pmap->pmapVmmExtPhys = 0;                                       /* Forget extension block's physical address, too */
        }
        pmap->pmapFlags &= ~pmapVMhost;                                 /* We're no longer hosting */

        kfree(CTable, sizeof(vmmCntrlTable));   /* Toss the table because to tossed the last context */
        act->machine.vmmControl = 0;                                            /* Unmark us as vmm */

        ml_set_interrupts_enabled(FALSE);                               /* No more interruptions */
        
        return KERN_SUCCESS;
}


/*-----------------------------------------------------------------------
** vmm_activate_XA
**
** This function activates the eXtended Architecture flags for the specifed VM.
** 
** We need to return the result in the return code rather than in the return parameters
** because we need an architecture independent format so the results are actually 
** usable by the host. For example, the return parameters for 64-bit are 8 bytes wide vs.
** 4 for 32-bit. 
** 
** Note that this function does a lot of the same stuff as vmm_tear_down_context
** and vmm_init_context.
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**              flags - the extended architecture flags
**              
**
** Outputs:
**              KERN_SUCCESS if vm is valid and initialized. KERN_FAILURE if not.
**              Also, the internal flags are set and, additionally, the VM is completely reset.
-----------------------------------------------------------------------*/
kern_return_t vmm_activate_XA(
        thread_t                        act,
        vmm_thread_index_t      index,
        unsigned int xaflags)
{
        vmmCntrlEntry           *CEntry;
        kern_return_t           result  = KERN_SUCCESS;         /* Assume success */

        if ((xaflags & ~kVmmSupportedSetXA) || ((xaflags & vmm64Bit) && (!getPerProc()->pf.Available & pf64Bit)))
                return (KERN_FAILURE);                                          /* Unknown or unsupported feature requested */
                
        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't a vmm or the index is bogus */

        ml_set_interrupts_enabled(TRUE);                                /* This can take a bit of time so pass interruptions */
        
        vmm_flush_context(act, index);                                  /* Flush the context */

        if (xaflags & vmm64Bit) {                                               /* Activating 64-bit mode ? */  
                CEntry->vmmXAFlgs |= vmm64Bit;                          /* Activate 64-bit mode */
        }
        
        if (xaflags & vmmGSA) {                                                 /* Activating guest shadow assist ? */
                result = vmm_activate_gsa(act, index);          /* Activate guest shadow assist */
        }
        
        ml_set_interrupts_enabled(FALSE);                               /* No more interruptions */
        
        return result;                                                                  /* Return activate result */
}

/*-----------------------------------------------------------------------
** vmm_deactivate_XA
**
-----------------------------------------------------------------------*/
kern_return_t vmm_deactivate_XA(
        thread_t                        act,
        vmm_thread_index_t      index,
        unsigned int xaflags)
{
        vmmCntrlEntry           *CEntry;
        kern_return_t           result  = KERN_SUCCESS;         /* Assume success */

        if ((xaflags & ~kVmmSupportedSetXA) || ((xaflags & vmm64Bit) && (getPerProc()->pf.Available & pf64Bit)))
                return (KERN_FAILURE);                                          /* Unknown or unsupported feature requested */
                
        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't a vmm or the index is bogus */

        ml_set_interrupts_enabled(TRUE);                                /* This can take a bit of time so pass interruptions */
        
        vmm_flush_context(act, index);                                  /* Flush the context */

        if (xaflags & vmm64Bit) {                                               /* Deactivating 64-bit mode ? */        
                CEntry->vmmXAFlgs &= ~vmm64Bit;                         /* Deactivate 64-bit mode */
        }
        
        if (xaflags & vmmGSA) {                                                 /* Deactivating guest shadow assist ? */
                vmm_deactivate_gsa(act, index);                         /* Deactivate guest shadow assist */
        }
        
        ml_set_interrupts_enabled(FALSE);                               /* No more interruptions */
        
        return result;                                                                  /* Return deactivate result */
}


/*-----------------------------------------------------------------------
** vmm_tear_down_all
**
** This function uninitializes all emulation contexts. If there are
** any vmm contexts, it calls vmm_tear_down_context for each one.
**
** Note: this can also be called from normal thread termination.  Because of
** that, we will context switch out of an alternate if we are currenty in it.
** It will be terminated with no valid return code set because we don't expect 
** the activation to ever run again.
**
** Inputs:
**              activation to tear down
**
** Outputs:
**              All vmm contexts released and VMM shut down
-----------------------------------------------------------------------*/
void vmm_tear_down_all(thread_t act) {

        vmmCntrlTable           *CTable;
        int                                     cvi;
        kern_return_t           ret;
        savearea                        *save;
        spl_t                           s;
        
        if(act->machine.specFlags & runningVM) {                        /* Are we actually in a context right now? */
                save = find_user_regs(act);                                     /* Find the user state context */
                if(!save) {                                                                     /* Did we find it? */
                        panic("vmm_tear_down_all: runningVM marked but no user state context\n");
                        return;
                }
                
                save->save_exception = kVmmBogusContext*4;      /* Indicate that this context is bogus now */
                s = splhigh();                                                          /* Make sure interrupts are off */
                vmm_force_exit(act, save);                                      /* Force and exit from VM state */
                splx(s);                                                                        /* Restore interrupts */
        }
        
        if(CTable = act->machine.vmmControl) {                          /* Do we have a vmm control block? */


                for(cvi = 1; cvi <= kVmmMaxContexts; cvi++) {   /* Look at all slots */
                        if(CTable->vmmc[cvi - 1].vmmFlags & vmmInUse) { /* Is this one in use */
                                ret = vmm_tear_down_context(act, cvi);  /* Take down the found context */
                                if(ret != KERN_SUCCESS) {                       /* Did it go away? */
                                        panic("vmm_tear_down_all: vmm_tear_down_context failed; ret=%08X, act = %08X, cvi = %d\n",
                                          ret, act, cvi);
                                }
                        }
                }               

/*
 *              Note that all address apces should be gone here.
 */
                if(act->machine.vmmControl) {                                           /* Did we find one? */
                        panic("vmm_tear_down_all: control table did not get deallocated\n");    /* Table did not go away */
                }
        }

        return;
}

/*-----------------------------------------------------------------------
** vmm_map_page
**
** This function maps a page from within the client's logical
** address space into the alternate address space.
**
** The page need not be locked or resident.  If not resident, it will be faulted
** in by this code, which may take some time.   Also, if the page is not locked,
** it, and this mapping may disappear at any time, even before it gets used.  Note also
** that reference and change information is NOT preserved when a page is unmapped, either
** explicitly or implicitly (e.g., a pageout, being unmapped in the non-alternate address
** space).  This means that if RC is needed, the page MUST be wired.
**
** Note that if there is already a mapping at the address, it is removed and all 
** information (including RC) is lost BEFORE an attempt is made to map it. Also,
** if the map call fails, the old address is still unmapped..
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of address space to map into
**              va    - virtual address within the client's address
**                          space
**              ava   - virtual address within the alternate address
**                          space
**              prot - protection flags
**
**      Note that attempted mapping of areas in nested pmaps (shared libraries) or block mapped
**  areas are not allowed and will fail. Same with directly mapped I/O areas.
**
** Input conditions:
**      Interrupts disabled (from fast trap)
**
** Outputs:
**              kernel return code indicating success or failure
**      if success, va resident and alternate mapping made
-----------------------------------------------------------------------*/

kern_return_t vmm_map_page(
        thread_t                        act,
        vmm_adsp_id_t           index,
        addr64_t                        cva,
        addr64_t                        ava,
        vm_prot_t                       prot)
{
        kern_return_t           ret;
        register mapping_t      *mp;
        vm_map_t                        map;
        addr64_t                        ova, nextva;
        pmap_t                          pmap;

        pmap = vmm_get_adsp(act, index);                        /* Get the guest pmap for this address space */
        if(!pmap) return KERN_FAILURE;                          /* Bogus address space, no VMs, or we can't make a pmap, failure... */

        if(ava > vm_max_address) return kVmmInvalidAddress;     /* Does the machine support an address of this size? */

        map = current_thread()->map;                            /* Get the host's map */

        if (pmap->pmapFlags & pmapVMgsaa) {                     /* Guest shadow assist active ? */
                ret = hw_res_map_gv(map->pmap, pmap, cva, ava, getProtPPC(prot));
                                                                                                /* Attempt to resume an existing gv->phys mapping */
                if (mapRtOK != ret) {                                   /* Nothing to resume, construct a new mapping */
                        
                        while (1) {                                                     /* Find host mapping or fail */
                                mp = mapping_find(map->pmap, cva, &nextva, 0);
                                                                                                /* Attempt to find host mapping and pin it */
                                if (mp) break;                                  /* Got it */
                                
                                ml_set_interrupts_enabled(TRUE);
                                                                                                /* Open 'rupt window */
                                ret = vm_fault(map,                             /* Didn't find it, try to fault in host page read/write */
                                        vm_map_trunc_page(cva), 
                                        VM_PROT_READ | VM_PROT_WRITE,
                                        FALSE, /* change wiring */
                                        THREAD_UNINT,
                                        NULL,
                                        0);
                                ml_set_interrupts_enabled(FALSE);
                                                                                                /* Close 'rupt window */
                                if (ret != KERN_SUCCESS)
                                        return KERN_FAILURE;            /* Fault failed, return failure */
                        }
                        
                        if (mpNormal != (mp->mpFlags & mpType)) {
                                                                                                /* Host mapping must be a vanilla page */
                                mapping_drop_busy(mp);                  /* Un-pin host mapping */
                                return KERN_FAILURE;                    /* Return failure */
                        }
        
                                                                                                /* Partially construct gv->phys mapping */
                        unsigned int  pindex;
                        phys_entry_t *physent = mapping_phys_lookup(mp->mpPAddr, &pindex);
                        if (!physent) {
                                mapping_drop_busy(mp);
                                return KERN_FAILURE;
                        }
                        unsigned int pattr = ((physent->ppLink & (ppI | ppG)) >> 60);
                        unsigned int wimg = 0x2;
                        if (pattr & mmFlgCInhib)  wimg |= 0x4;
                        if (pattr & mmFlgGuarded) wimg |= 0x1;
                        unsigned int mflags = (pindex << 16) | mpGuest;
                        addr64_t         gva = ((ava & ~mpHWFlags) | (wimg << 3) | getProtPPC(prot));
                        
                        hw_add_map_gv(map->pmap, pmap, gva, mflags, mp->mpPAddr);
                                                                                                /* Construct new guest->phys mapping */
                        
                        mapping_drop_busy(mp);                          /* Un-pin host mapping */
                }
        } else {
                while(1) {                                                              /* Keep trying until we get it or until we fail */
        
                        mp = mapping_find(map->pmap, cva, &nextva, 0);  /* Find the mapping for this address */
                        
                        if(mp) break;                                           /* We found it */
        
                        ml_set_interrupts_enabled(TRUE);        /* Enable interruptions */
                        ret = vm_fault(map,                                     /* Didn't find it, try to fault it in read/write... */
                                        vm_map_trunc_page(cva), 
                                        VM_PROT_READ | VM_PROT_WRITE,
                                        FALSE, /*change wiring */
                                        THREAD_UNINT,
                                        NULL,
                                        0);
                        ml_set_interrupts_enabled(FALSE);       /* Disable interruptions */
                        if (ret != KERN_SUCCESS) return KERN_FAILURE;   /* There isn't a page there, return... */
                }
        
                if((mp->mpFlags & mpType) != mpNormal) {        /* If this is a block, a nest, or some other special thing, we can't map it */
                        mapping_drop_busy(mp);                          /* We have everything we need from the mapping */
                        return KERN_FAILURE;                            /* Leave in shame */
                }
                
                while(1) {                                                              /* Keep trying the enter until it goes in */
                        ova = mapping_make(pmap, ava, mp->mpPAddr, 0, 1, prot); /* Enter the mapping into the pmap */
                        if(!ova) break;                                         /* If there were no collisions, we are done... */
                        mapping_remove(pmap, ova);                      /* Remove the mapping that collided */
                }
        
                mapping_drop_busy(mp);                                  /* We have everything we need from the mapping */
        }

        if (!((getPerProc()->spcFlags) & FamVMmode)) {
                act->machine.vmmControl->vmmLastMap = ava & 0xFFFFFFFFFFFFF000ULL;      /* Remember the last mapping we made */
                act->machine.vmmControl->vmmGFlags = (act->machine.vmmControl->vmmGFlags & ~vmmLastAdSp) | index;       /* Remember last address space */
        }

        return KERN_SUCCESS;
}


/*-----------------------------------------------------------------------
** vmm_map_execute
**
** This function maps a page from within the client's logical
** address space into the alternate address space of the
** Virtual Machine Monitor context and then directly starts executing.
**
**      See description of vmm_map_page for details. 
**
** Inputs:
**              Index is used for both the context and the address space ID.
**              index[24:31] is the context id and index[16:23] is the address space.
**              if the address space ID is 0, the context ID is used for it.
**
** Outputs:
**              Normal exit is to run the VM.  Abnormal exit is triggered via a 
**              non-KERN_SUCCESS return from vmm_map_page or later during the 
**              attempt to transition into the VM. 
-----------------------------------------------------------------------*/

vmm_return_code_t vmm_map_execute(
        thread_t                        act,
        vmm_thread_index_t      index,
        addr64_t                        cva,
        addr64_t                        ava,
        vm_prot_t                       prot)
{
        kern_return_t           ret;
        vmmCntrlEntry           *CEntry;
        unsigned int            adsp;
        vmm_thread_index_t      cndx;

        cndx = index & 0xFF;                                                    /* Clean it up */

        CEntry = vmm_get_entry(act, cndx);                              /* Get and validate the index */
        if (CEntry == NULL) return kVmmBogusContext;    /* Return bogus context */
        
        if (((getPerProc()->spcFlags) & FamVMmode) && (CEntry != act->machine.vmmCEntry))
                return kVmmBogusContext;                        /* Yes, invalid index in Fam */
        
        adsp = (index >> 8) & 0xFF;                                             /* Get any requested address space */
        if(!adsp) adsp = (index & 0xFF);                                /* If 0, use context ID as address space ID */
        
        ret = vmm_map_page(act, adsp, cva, ava, prot);  /* Go try to map the page on in */
        
        
        if(ret == KERN_SUCCESS) {
                act->machine.vmmControl->vmmLastMap = ava & 0xFFFFFFFFFFFFF000ULL;      /* Remember the last mapping we made */
                act->machine.vmmControl->vmmGFlags = (act->machine.vmmControl->vmmGFlags & ~vmmLastAdSp) | cndx;        /* Remember last address space */
                vmm_execute_vm(act, cndx);                              /* Return was ok, launch the VM */
        }
        
        return ret;                                                                             /* We had trouble mapping in the page */        
        
}

/*-----------------------------------------------------------------------
** vmm_map_list
**
** This function maps a list of pages into various address spaces
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of default address space (used if not specifed in list entry
**              count - number of pages to release
**              flavor - 0 if 32-bit version, 1 if 64-bit
**              vmcpComm in the comm page contains up to kVmmMaxMapPages to map
**
** Outputs:
**              kernel return code indicating success or failure
**              KERN_FAILURE is returned if kVmmMaxUnmapPages is exceeded
**              or the vmm_map_page call fails.
**              We return kVmmInvalidAddress if virtual address size is not supported
-----------------------------------------------------------------------*/

kern_return_t vmm_map_list(
        thread_t                        act,
        vmm_adsp_id_t           index,
        unsigned int            cnt,
        unsigned int            flavor)
{
        vmmCntrlEntry           *CEntry;
        boolean_t                       ret;
        unsigned int            i;
        vmmMList                        *lst;
        vmmMList64                      *lstx;
        addr64_t                        cva;
        addr64_t                        ava;
        vm_prot_t                       prot;
        vmm_adsp_id_t           adsp;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't a vmm or the index is bogus */
        
        if(cnt > kVmmMaxMapPages) return KERN_FAILURE;  /* They tried to map too many */
        if(!cnt) return KERN_SUCCESS;                                   /* If they said none, we're done... */
        
        lst = (vmmMList *)&((vmm_comm_page_t *)CEntry->vmmContextKern)->vmcpComm[0];    /* Point to the first entry */
        lstx = (vmmMList64 *)&((vmm_comm_page_t *)CEntry->vmmContextKern)->vmcpComm[0]; /* Point to the first entry */
        
        for(i = 0; i < cnt; i++) {                                              /* Step and release all pages in list */
                if(flavor) {                                                            /* Check if 32- or 64-bit addresses */
                        cva = lstx[i].vmlva;                                    /* Get the 64-bit actual address */     
                        ava = lstx[i].vmlava;                                   /* Get the 64-bit guest address */      
                }
                else {
                        cva = lst[i].vmlva;                                             /* Get the 32-bit actual address */     
                        ava = lst[i].vmlava;                                    /* Get the 32-bit guest address */      
                }

                prot = ava & vmmlProt;                                          /* Extract the protection bits */       
                adsp = (ava & vmmlAdID) >> 4;                           /* Extract an explicit address space request */ 
                if(!adsp) adsp = index - 1;                                     /* If no explicit, use supplied default */
                ava = ava &= 0xFFFFFFFFFFFFF000ULL;                     /* Clean up the address */
                
                ret = vmm_map_page(act, index, cva, ava, prot); /* Go try to map the page on in */
                if(ret != KERN_SUCCESS) return ret;                     /* Bail if any error */
        }
        
        return KERN_SUCCESS     ;                                                       /* Return... */
}

/*-----------------------------------------------------------------------
** vmm_get_page_mapping
**
** Given a context index and a guest virtual address, convert the address
** to its corresponding host virtual address.
**
** Inputs:
**              act   - pointer to current thread activation
**              index - context index
**              gva   - guest virtual address 
**
** Outputs:
**              Host virtual address (page aligned) or -1 if not mapped or any failure
**
** Note:
**              If the host address space contains multiple virtual addresses mapping
**              to the physical address corresponding to the specified guest virtual
**              address (i.e., host virtual aliases), it is unpredictable which host
**              virtual address (alias) will be returned. Moral of the story: No host
**              virtual aliases.
-----------------------------------------------------------------------*/

addr64_t vmm_get_page_mapping(
        thread_t                        act,
        vmm_adsp_id_t           index,
        addr64_t                        gva)
{
        register mapping_t      *mp;
        pmap_t                          pmap;
        addr64_t                        nextva, hva;
        ppnum_t                         pa;

        pmap = vmm_get_adsp(act, index);                                /* Get and validate the index */
        if (!pmap)return -1;                                                    /* No good, failure... */
        
        if (pmap->pmapFlags & pmapVMgsaa) {                             /* Guest shadow assist (GSA) active ? */
                return (hw_gva_to_hva(pmap, gva));                      /* Convert guest to host virtual address */                     
        } else {
                mp = mapping_find(pmap, gva, &nextva, 0);       /* Find guest mapping for this virtual address */
        
                if(!mp) return -1;                                                      /* Not mapped, return -1 */

                pa = mp->mpPAddr;                                                       /* Remember the physical page address */

                mapping_drop_busy(mp);                                          /* Go ahead and relase the mapping now */
        
                pmap = current_thread()->map->pmap;                     /* Get the host pmap */
                hva = mapping_p2v(pmap, pa);                            /* Now find the source virtual */

                if(hva != 0) return hva;                                        /* We found it... */
        
                panic("vmm_get_page_mapping: could not back-map guest va (%016llX)\n", gva);
                                                                                                        /* We are bad wrong if we can't find it */

                return -1;                                                                      /* Never executed, prevents compiler warning */
        }
}

/*-----------------------------------------------------------------------
** vmm_unmap_page
**
** This function unmaps a page from the guest address space.
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of vmm state for this page
**              va    - virtual address within the vmm's address
**                          space
**
** Outputs:
**              kernel return code indicating success or failure
-----------------------------------------------------------------------*/

kern_return_t vmm_unmap_page(
        thread_t                        act,
        vmm_adsp_id_t           index,
        addr64_t                        va)
{
        vmmCntrlEntry           *CEntry;
        addr64_t                        nadd;
        pmap_t                          pmap;

        pmap = vmm_get_adsp(act, index);                                                /* Get and validate the index */
        if (!pmap)return -1;                                                                    /* No good, failure... */
        
        if (pmap->pmapFlags & pmapVMgsaa) {                                             /* Handle guest shadow assist specially */
                hw_susp_map_gv(act->map->pmap, pmap, va);                       /* Suspend the mapping */
                return (KERN_SUCCESS);                                                          /* Always returns success */
        } else {
                nadd = mapping_remove(pmap, va);                                        /* Toss the mapping */
                
                return ((nadd & 1) ? KERN_FAILURE : KERN_SUCCESS);      /* Return... */
        }
}

/*-----------------------------------------------------------------------
** vmm_unmap_list
**
** This function unmaps a list of pages from the alternate's logical
** address space.
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of vmm state for this page
**              count - number of pages to release
**              flavor - 0 if 32-bit, 1 if 64-bit
**              vmcpComm in the comm page contains up to kVmmMaxUnmapPages to unmap
**
** Outputs:
**              kernel return code indicating success or failure
**              KERN_FAILURE is returned if kVmmMaxUnmapPages is exceeded
-----------------------------------------------------------------------*/

kern_return_t vmm_unmap_list(
        thread_t                        act,
        vmm_adsp_id_t           index,
        unsigned int            cnt,
        unsigned int            flavor)
{
        vmmCntrlEntry           *CEntry;
        boolean_t                       ret;
        kern_return_t           kern_result = KERN_SUCCESS;
        unsigned int            *pgaddr, i;
        addr64_t                        gva;
        vmmUMList                       *lst;
        vmmUMList64                     *lstx;
        pmap_t                          pmap;
        int                                     adsp;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't a vmm or the index is bogus */
        
        if(cnt > kVmmMaxUnmapPages) return KERN_FAILURE;        /* They tried to unmap too many */
        if(!cnt) return KERN_SUCCESS;                                   /* If they said none, we're done... */
        
        lst = (vmmUMList *)lstx = (vmmUMList64 *) &((vmm_comm_page_t *)CEntry->vmmContextKern)->vmcpComm[0];    /* Point to the first entry */
        
        for(i = 0; i < cnt; i++) {                                              /* Step and release all pages in list */
                if(flavor) {                                                            /* Check if 32- or 64-bit addresses */
                        gva = lstx[i].vmlava;                                   /* Get the 64-bit guest address */      
                }
                else {
                        gva = lst[i].vmlava;                                    /* Get the 32-bit guest address */      
                }

                adsp = (gva & vmmlAdID) >> 4;                           /* Extract an explicit address space request */ 
                if(!adsp) adsp = index - 1;                                     /* If no explicit, use supplied default */
                pmap = act->machine.vmmControl->vmmAdsp[adsp];  /* Get the pmap for this request */
                if(!pmap) continue;                                                     /* Ain't nuthin' mapped here, no durn map... */

                gva = gva &= 0xFFFFFFFFFFFFF000ULL;                     /* Clean up the address */      
                if (pmap->pmapFlags & pmapVMgsaa) {                     /* Handle guest shadow assist specially */
                        hw_susp_map_gv(act->map->pmap, pmap, gva);
                                                                                                        /* Suspend the mapping */
                } else {
                        (void)mapping_remove(pmap, gva);                /* Toss the mapping */
                }
        }
        
        return KERN_SUCCESS     ;                                                       /* Return... */
}

/*-----------------------------------------------------------------------
** vmm_unmap_all_pages
**
** This function unmaps all pages from the alternates's logical
** address space.
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of context state
**
** Outputs:
**              none
**
** Note:
**      All pages are unmapped, but the address space (i.e., pmap) is still alive
-----------------------------------------------------------------------*/

void vmm_unmap_all_pages(
        thread_t                        act,
        vmm_adsp_id_t           index)
{
        vmmCntrlEntry           *CEntry;
        pmap_t                          pmap;

        pmap = vmm_get_adsp(act, index);                                                /* Convert index to entry */            
        if (!pmap) return;                                                                              /* Either this isn't vmm thread or the index is bogus */

        if (pmap->pmapFlags & pmapVMgsaa) {                                             /* Handle guest shadow assist specially */
                hw_rem_all_gv(pmap);                                                            /* Remove all guest's mappings from shadow hash table */
        } else {
                /*
                 *      Note: the pmap code won't deal with the last page in the address space, so handle it explicitly
                 */
                mapping_remove(pmap, 0xFFFFFFFFFFFFF000LL);                     /* Remove final page explicitly because we might have mapped it */      
                pmap_remove(pmap, 0, 0xFFFFFFFFFFFFF000LL);                     /* Remove all entries from this map */
        }
        return;
}


/*-----------------------------------------------------------------------
** vmm_get_page_dirty_flag
**
** This function returns the changed flag of the page
** and optionally clears clears the flag.
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of vmm state for this page
**              va    - virtual address within the vmm's address
**                          space
**              reset - Clears dirty if true, untouched if not
**
** Outputs:
**              the dirty bit
**              clears the dirty bit in the pte if requested
**
**      Note:
**              The RC bits are merged into the global physical entry
-----------------------------------------------------------------------*/

boolean_t vmm_get_page_dirty_flag(
        thread_t                        act,
        vmm_adsp_id_t           index,
        addr64_t                        va,
        unsigned int            reset)
{
        vmmCntrlEntry           *CEntry;
        register mapping_t      *mpv, *mp;
        unsigned int            RC;
        pmap_t                          pmap;

        pmap = vmm_get_adsp(act, index);                                                /* Convert index to entry */            
        if (!pmap) return 1;                                                                    /* Either this isn't vmm thread or the index is bogus */

        if (pmap->pmapFlags & pmapVMgsaa) {                                             /* Handle guest shadow assist specially */
                RC = hw_test_rc_gv(act->map->pmap, pmap, va, reset);/* Fetch the RC bits and clear if requested */      
        } else {
                RC = hw_test_rc(pmap, (addr64_t)va, reset);                     /* Fetch the RC bits and clear if requested */
        }

        switch (RC & mapRetCode) {                                                              /* Decode return code */
        
                case mapRtOK:                                                                           /* Changed */
                        return ((RC & (unsigned int)mpC) == (unsigned int)mpC); /* Return if dirty or not */
                        break;
        
                case mapRtNotFnd:                                                                       /* Didn't find it */
                        return 1;                                                                               /* Return dirty */
                        break;
                        
                default:
                        panic("vmm_get_page_dirty_flag: hw_test_rc failed - rc = %d, pmap = %08X, va = %016llX\n", RC, pmap, va);
                
        }

        return 1;                                                                                               /* Return the change bit */
}


/*-----------------------------------------------------------------------
** vmm_protect_page
**
** This function sets the protection bits of a mapped page
**
** Inputs:
**              act   - pointer to current thread activation
**              index - index of vmm state for this page
**              va    - virtual address within the vmm's address
**                          space
**              prot  - Protection flags
**
** Outputs:
**              none
**              Protection bits of the mapping are modifed
**
-----------------------------------------------------------------------*/

kern_return_t vmm_protect_page(
        thread_t                        act,
        vmm_adsp_id_t           index,
        addr64_t                        va,
        vm_prot_t                       prot)
{
        vmmCntrlEntry           *CEntry;
        addr64_t                        nextva;
        int     ret;
        pmap_t                          pmap;

        pmap = vmm_get_adsp(act, index);                                                /* Convert index to entry */            
        if (!pmap) return KERN_FAILURE;                                                 /* Either this isn't vmm thread or the index is bogus */
        
        if (pmap->pmapFlags & pmapVMgsaa) {                                             /* Handle guest shadow assist specially */
                ret = hw_protect_gv(pmap, va, prot);                            /* Try to change protection, GSA varient */
        } else {
                ret = hw_protect(pmap, va, prot, &nextva);                      /* Try to change protection */
        }

        switch (ret) {                                                                                  /* Decode return code */
        
                case mapRtOK:                                                                           /* All ok... */
                        break;                                                                                  /* Outta here */
                        
                case mapRtNotFnd:                                                                       /* Didn't find it */
                        return KERN_SUCCESS;                                                    /* Ok, return... */
                        break;
                        
                default:
                        panic("vmm_protect_page: hw_protect failed - rc = %d, pmap = %08X, va = %016llX\n", ret, pmap, (addr64_t)va);
                
        }

        if (!((getPerProc()->spcFlags) & FamVMmode)) {
                act->machine.vmmControl->vmmLastMap = va & 0xFFFFFFFFFFFFF000ULL;       /* Remember the last mapping we made */
                act->machine.vmmControl->vmmGFlags = (act->machine.vmmControl->vmmGFlags & ~vmmLastAdSp) | index;       /* Remember last address space */
        }

        return KERN_SUCCESS;                                                                    /* Return */
}


/*-----------------------------------------------------------------------
** vmm_protect_execute
**
** This function sets the protection bits of a mapped page
** and then directly starts executing.
**
**      See description of vmm_protect_page for details
**
** Inputs:
**              See vmm_protect_page and vmm_map_execute
**
** Outputs:
**              Normal exit is to run the VM.  Abnormal exit is triggered via a 
**              non-KERN_SUCCESS return from vmm_map_page or later during the 
**              attempt to transition into the VM. 
-----------------------------------------------------------------------*/

vmm_return_code_t vmm_protect_execute(
        thread_t                        act,
        vmm_thread_index_t      index,
        addr64_t                        va,
        vm_prot_t                       prot)
{
        kern_return_t           ret;
        vmmCntrlEntry           *CEntry;
        unsigned int            adsp;
        vmm_thread_index_t      cndx;

        cndx = index & 0xFF;                                                    /* Clean it up */
        CEntry = vmm_get_entry(act, cndx);                              /* Get and validate the index */
        if (CEntry == NULL) return kVmmBogusContext;    /* Return bogus context */
        
        adsp = (index >> 8) & 0xFF;                                             /* Get any requested address space */
        if(!adsp) adsp = (index & 0xFF);                                /* If 0, use context ID as address space ID */
        
        if (((getPerProc()->spcFlags) & FamVMmode) && (CEntry != act->machine.vmmCEntry))
                return kVmmBogusContext;                        /* Yes, invalid index in Fam */
        
        ret = vmm_protect_page(act, adsp, va, prot);    /* Go try to change access */
        
        if(ret == KERN_SUCCESS) {
                act->machine.vmmControl->vmmLastMap = va & 0xFFFFFFFFFFFFF000ULL;       /* Remember the last mapping we made */
                act->machine.vmmControl->vmmGFlags = (act->machine.vmmControl->vmmGFlags & ~vmmLastAdSp) | cndx;        /* Remember last address space */
                vmm_execute_vm(act, cndx);      /* Return was ok, launch the VM */
        }
        
        return ret;                                                                             /* We had trouble of some kind (shouldn't happen) */    
        
}


/*-----------------------------------------------------------------------
** vmm_get_float_state
**
** This function causes the current floating point state to 
** be saved into the shared context area.  It also clears the
** vmmFloatCngd changed flag.
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**
** Outputs:
**              context saved
-----------------------------------------------------------------------*/

kern_return_t vmm_get_float_state(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry           *CEntry;
        vmmCntrlTable           *CTable;
        int                                     i;
        register struct savearea_fpu *sv;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't vmm thread or the index is bogus */
        
        act->machine.specFlags &= ~floatCng;                            /* Clear the special flag */
        CEntry->vmmContextKern->vmmStat &= ~vmmFloatCngd;       /* Clear the change indication */

        fpu_save(&CEntry->vmmFacCtx);                                   /* Save context if live */

        if(sv = CEntry->vmmFacCtx.FPUsave) {                    /* Is there context yet? */
                bcopy((char *)&sv->save_fp0, (char *)&(CEntry->vmmContextKern->vmm_proc_state.ppcFPRs), 32 * 8); /* 32 registers */
                return KERN_SUCCESS;
        }


        for(i = 0; i < 32; i++) {                                               /* Initialize floating points */
                CEntry->vmmContextKern->vmm_proc_state.ppcFPRs[i].d = FloatInit;        /* Initial value */
        }

        return KERN_SUCCESS;
}

/*-----------------------------------------------------------------------
** vmm_get_vector_state
**
** This function causes the current vector state to 
** be saved into the shared context area.  It also clears the
** vmmVectorCngd changed flag.
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**
** Outputs:
**              context saved
-----------------------------------------------------------------------*/

kern_return_t vmm_get_vector_state(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry           *CEntry;
        vmmCntrlTable           *CTable;
        int                                     i, j;
        unsigned int            vrvalidwrk;
        register struct savearea_vec *sv;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't vmm thread or the index is bogus */

        vec_save(&CEntry->vmmFacCtx);                                   /* Save context if live */
        
        act->machine.specFlags &= ~vectorCng;                           /* Clear the special flag */
        CEntry->vmmContextKern->vmmStat &= ~vmmVectCngd;        /* Clear the change indication */
        
        if(sv = CEntry->vmmFacCtx.VMXsave) {                    /* Is there context yet? */

                vrvalidwrk = sv->save_vrvalid;                          /* Get the valid flags */

                for(i = 0; i < 32; i++) {                                       /* Copy the saved registers and invalidate the others */
                        if(vrvalidwrk & 0x80000000) {                   /* Do we have a valid value here? */
                                for(j = 0; j < 4; j++) {                        /* If so, copy it over */
                                        CEntry->vmmContextKern->vmm_proc_state.ppcVRs[i].i[j] = ((unsigned int *)&(sv->save_vr0))[(i * 4) + j];
                                }
                        }
                        else {
                                for(j = 0; j < 4; j++) {                        /* Otherwise set to empty value */
                                        CEntry->vmmContextKern->vmm_proc_state.ppcVRs[i].i[j] = QNaNbarbarian[j];
                                }
                        }
                        
                        vrvalidwrk = vrvalidwrk << 1;                   /* Shift over to the next */
                        
                }

                return KERN_SUCCESS;
        }

        for(i = 0; i < 32; i++) {                                               /* Initialize vector registers */
                for(j=0; j < 4; j++) {                                          /* Do words */
                        CEntry->vmmContextKern->vmm_proc_state.ppcVRs[i].i[j] = QNaNbarbarian[j];               /* Initial value */
                }
        }

        return KERN_SUCCESS;
}

/*-----------------------------------------------------------------------
** vmm_set_timer
**
** This function causes a timer (in AbsoluteTime) for a specific time
** to be set  It also clears the vmmTimerPop flag if the timer is actually 
** set, it is cleared otherwise.
**
** A timer is cleared by setting setting the time to 0. This will clear
** the vmmTimerPop bit. Simply setting the timer to earlier than the
** current time clears the internal timer request, but leaves the
** vmmTimerPop flag set.
** 
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**              timerhi - high order word of AbsoluteTime to pop
**              timerlo - low order word of AbsoluteTime to pop
**
** Outputs:
**              timer set, vmmTimerPop cleared
-----------------------------------------------------------------------*/

kern_return_t vmm_set_timer(
        thread_t                        act,
        vmm_thread_index_t      index,
        unsigned int            timerhi, 
        unsigned int            timerlo)
{
        vmmCntrlEntry           *CEntry;
                
        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't vmm thread or the index is bogus */
        
        CEntry->vmmTimer = ((uint64_t)timerhi << 32) | timerlo;
        
        vmm_timer_pop(act);                                                             /* Go adjust all of the timer stuff */
        return KERN_SUCCESS;                                                    /* Leave now... */
}


/*-----------------------------------------------------------------------
** vmm_get_timer
**
** This function causes the timer for a specified VM to be
** returned in return_params[0] and return_params[1].
** Note that this is kind of funky for 64-bit VMs because we
** split the timer into two parts so that we still set parms 0 and 1.
** Obviously, we don't need to do this because the parms are 8 bytes
** wide.
** 
**
** Inputs:
**              act - pointer to current thread activation structure
**              index - index returned by vmm_init_context
**
** Outputs:
**              Timer value set in return_params[0] and return_params[1].
**              Set to 0 if timer is not set.
-----------------------------------------------------------------------*/

kern_return_t vmm_get_timer(
        thread_t                        act,
        vmm_thread_index_t      index)
{
        vmmCntrlEntry           *CEntry;
        vmmCntrlTable           *CTable;

        CEntry = vmm_get_entry(act, index);                             /* Convert index to entry */            
        if (CEntry == NULL) return KERN_FAILURE;                /* Either this isn't vmm thread or the index is bogus */

        if(CEntry->vmmXAFlgs & vmm64Bit) {                              /* A 64-bit virtual machine? */
                CEntry->vmmContextKern->vmmRet.vmmrp64.return_params[0] = (uint32_t)(CEntry->vmmTimer >> 32);   /* Return the last timer value */
                CEntry->vmmContextKern->vmmRet.vmmrp64.return_params[1] = (uint32_t)CEntry->vmmTimer;   /* Return the last timer value */
        }
        else {
                CEntry->vmmContextKern->vmmRet.vmmrp32.return_params[0] = (CEntry->vmmTimer >> 32);     /* Return the last timer value */
                CEntry->vmmContextKern->vmmRet.vmmrp32.return_params[1] = (uint32_t)CEntry->vmmTimer;   /* Return the last timer value */
        }
        return KERN_SUCCESS;
}


/*-----------------------------------------------------------------------
** vmm_timer_pop
**
** This function causes all timers in the array of VMs to be updated.
** All appropriate flags are set or reset.  If a VM is currently
** running and its timer expired, it is intercepted.
**
** The qactTimer value is set to the lowest unexpired timer.  It is
** zeroed if all timers are expired or have been reset.
**
** Inputs:
**              act - pointer to current thread activation structure
**
** Outputs:
**              timers set, vmmTimerPop cleared or set
-----------------------------------------------------------------------*/

void vmm_timer_pop(
        thread_t                        act)
{
        vmmCntrlEntry           *CEntry;
        vmmCntrlTable           *CTable;
        int                                     cvi, any;
        uint64_t                        now, soonest;
        savearea                        *sv;
                
        if(!((unsigned int)act->machine.vmmControl & 0xFFFFFFFE)) {     /* Are there any virtual machines? */
                panic("vmm_timer_pop: No virtual machines defined; act = %08X\n", act);
        }

        soonest = 0xFFFFFFFFFFFFFFFFULL;                                /* Max time */

        clock_get_uptime(&now);                                                 /* What time is it? */
        
        CTable = act->machine.vmmControl;                                       /* Make this easier */  
        any = 0;                                                                                /* Haven't found a running unexpired timer yet */
        
        for(cvi = 0; cvi < kVmmMaxContexts; cvi++) {    /* Cycle through all and check time now */

                if(!(CTable->vmmc[cvi].vmmFlags & vmmInUse)) continue;  /* Do not check if the entry is empty */
                
                if(CTable->vmmc[cvi].vmmTimer == 0) {           /* Is the timer reset? */
                        CTable->vmmc[cvi].vmmFlags &= ~vmmTimerPop;                     /* Clear timer popped */
                        CTable->vmmc[cvi].vmmContextKern->vmmStat &= ~vmmTimerPop;      /* Clear timer popped */
                        continue;                                                               /* Check next */
                }

                if (CTable->vmmc[cvi].vmmTimer <= now) {
                        CTable->vmmc[cvi].vmmFlags |= vmmTimerPop;      /* Set timer popped here */
                        CTable->vmmc[cvi].vmmContextKern->vmmStat |= vmmTimerPop;       /* Set timer popped here */
                        if((unsigned int)&CTable->vmmc[cvi] == (unsigned int)act->machine.vmmCEntry) {  /* Is this the running VM? */
                                sv = find_user_regs(act);                       /* Get the user state registers */
                                if(!sv) {                                                       /* Did we find something? */
                                        panic("vmm_timer_pop: no user context; act = %08X\n", act);
                                }
                                sv->save_exception = kVmmReturnNull*4;  /* Indicate that this is a null exception */
                                vmm_force_exit(act, sv);                        /* Intercept a running VM */
                        }
                        continue;                                                               /* Check the rest */
                }
                else {                                                                          /* It hasn't popped yet */
                        CTable->vmmc[cvi].vmmFlags &= ~vmmTimerPop;     /* Set timer not popped here */
                        CTable->vmmc[cvi].vmmContextKern->vmmStat &= ~vmmTimerPop;      /* Set timer not popped here */
                }
                
                any = 1;                                                                        /* Show we found an active unexpired timer */
                
                if (CTable->vmmc[cvi].vmmTimer < soonest)
                        soonest = CTable->vmmc[cvi].vmmTimer;
        }
        
        if(any) {
                if (act->machine.qactTimer == 0 || soonest <= act->machine.qactTimer)
                        act->machine.qactTimer = soonest;       /* Set lowest timer */
        }

        return;
}



/*-----------------------------------------------------------------------
** vmm_stop_vm
**
** This function prevents the specified VM(s) to from running.
** If any is currently executing, the execution is intercepted
** with a code of kVmmStopped.  Note that execution of the VM is
** blocked until a vmmExecuteVM is called with the start flag set to 1.
** This provides the ability for a thread to stop execution of a VM and
** insure that it will not be run until the emulator has processed the
** "virtual" interruption.
**
** Inputs:
**              vmmask - 32 bit mask corresponding to the VMs to put in stop state
**                               NOTE: if this mask is all 0s, any executing VM is intercepted with
*                        a kVmmStopped (but not marked stopped), otherwise this is a no-op. Also note that there
**                               note that there is a potential race here and the VM may not stop.
**
** Outputs:
**              kernel return code indicating success
**      or if no VMs are enabled, an invalid syscall exception.
-----------------------------------------------------------------------*/

int vmm_stop_vm(struct savearea *save)
{

        thread_t                        act;
        vmmCntrlTable           *CTable;
        int                                     cvi, i;
    task_t                              task;
    thread_t                    fact;
    unsigned int                vmmask;
    ReturnHandler               *stopapc;

        ml_set_interrupts_enabled(TRUE);                        /* This can take a bit of time so pass interruptions */
        
        task = current_task();                                          /* Figure out who we are */

        task_lock(task);                                                        /* Lock our task */

        fact = (thread_t)task->threads.next;    /* Get the first activation on task */
        act = 0;                                                                        /* Pretend we didn't find it yet */

        for(i = 0; i < task->thread_count; i++) {       /* All of the activations */
                if(fact->machine.vmmControl) {                          /* Is this a virtual machine monitor? */
                        act = fact;                                                     /* Yeah... */
                        break;                                                          /* Bail the loop... */
                }
                fact = (thread_t)fact->task_threads.next;       /* Go to the next one */
        }

        if(!((unsigned int)act)) {                                      /* See if we have VMMs yet */
                task_unlock(task);                                              /* No, unlock the task */
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                return 0;                                                               /* Go generate a syscall exception */
        }

        thread_reference(act);

        task_unlock(task);                                                      /* Safe to release now */

        thread_mtx_lock(act);

        CTable = act->machine.vmmControl;                               /* Get the pointer to the table */
        
        if(!((unsigned int)CTable & -2)) {                      /* Are there any all the way up yet? */
                thread_mtx_unlock(act);                                 /* Unlock the activation */
                thread_deallocate(act);
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                return 0;                                                               /* Go generate a syscall exception */
        }
        
        if(!(vmmask = save->save_r3)) {                         /* Get the stop mask and check if all zeros */
                thread_mtx_unlock(act);                                 /* Unlock the activation */
                thread_deallocate(act);
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                save->save_r3 = KERN_SUCCESS;                   /* Set success */       
                return 1;                                                               /* Return... */
        }

        for(cvi = 0; cvi < kVmmMaxContexts; cvi++) {    /* Search slots */
                if((0x80000000 & vmmask) && (CTable->vmmc[cvi].vmmFlags & vmmInUse)) {  /* See if we need to stop and if it is in use */
                        hw_atomic_or(&CTable->vmmc[cvi].vmmFlags, vmmXStop);    /* Set this one to stop */
                }
                vmmask = vmmask << 1;                                   /* Slide mask over */
        }
        
        if(hw_compare_and_store(0, 1, &act->machine.emPendRupts)) {     /* See if there is already a stop pending and lock out others if not */
                thread_mtx_unlock(act);                                 /* Already one pending, unlock the activation */
                thread_deallocate(act);
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                save->save_r3 = KERN_SUCCESS;                   /* Say we did it... */  
                return 1;                                                               /* Leave */
        }

        if(!(stopapc = (ReturnHandler *)kalloc(sizeof(ReturnHandler)))) {       /* Get a return handler control block */
                act->machine.emPendRupts = 0;                           /* No memory, say we have given up request */
                thread_mtx_unlock(act);                                 /* Unlock the activation */
                thread_deallocate(act);
                ml_set_interrupts_enabled(FALSE);               /* Set back interruptions */
                save->save_r3 = KERN_RESOURCE_SHORTAGE; /* No storage... */
                return 1;                                                               /* Return... */
        }

        ml_set_interrupts_enabled(FALSE);                       /* Disable interruptions for now */

        stopapc->handler = vmm_interrupt;                       /* Set interruption routine */

        stopapc->next = act->handlers;                          /* Put our interrupt at the start of the list */
        act->handlers = stopapc;                                        /* Point to us */

        act_set_apc(act);                                                       /* Set an APC AST */
        ml_set_interrupts_enabled(TRUE);                        /* Enable interruptions now */

        thread_mtx_unlock(act);                                         /* Unlock the activation */
        thread_deallocate(act);
        
        ml_set_interrupts_enabled(FALSE);                       /* Set back interruptions */
        save->save_r3 = KERN_SUCCESS;                           /* Hip, hip, horay... */        
        return 1;
}

/*-----------------------------------------------------------------------
** vmm_interrupt
**
** This function is executed asynchronously from an APC AST.
** It is to be used for anything that needs to interrupt a running VM.
** This include any kind of interruption generation (other than timer pop)
** or entering the stopped state.
**
** Inputs:
**              ReturnHandler *rh - the return handler control block as required by the APC.
**              thread_t act  - the activation
**
** Outputs:
**              Whatever needed to be done is done.
-----------------------------------------------------------------------*/

void vmm_interrupt(ReturnHandler *rh, thread_t act) {

        vmmCntrlTable           *CTable;
        savearea                        *sv;
        boolean_t                       inter;



        kfree(rh, sizeof(ReturnHandler));       /* Release the return handler block */
        
        inter  = ml_set_interrupts_enabled(FALSE);      /* Disable interruptions for now */

        act->machine.emPendRupts = 0;                                   /* Say that there are no more interrupts pending */
        CTable = act->machine.vmmControl;                               /* Get the pointer to the table */
        
        if(!((unsigned int)CTable & -2)) return;        /* Leave if we aren't doing VMs any more... */

        if(act->machine.vmmCEntry && (act->machine.vmmCEntry->vmmFlags & vmmXStop)) {   /* Do we need to stop the running guy? */
                sv = find_user_regs(act);                               /* Get the user state registers */
                if(!sv) {                                                               /* Did we find something? */
                        panic("vmm_interrupt: no user context; act = %08X\n", act);
                }
                sv->save_exception = kVmmStopped*4;             /* Set a "stopped" exception */
                vmm_force_exit(act, sv);                                /* Intercept a running VM */
        }
        ml_set_interrupts_enabled(inter);                       /* Put interrupts back to what they were */

        return;
}