xnu-1504.15.3.tar.gz

[apple/xnu.git] / osfmk / ppc / vmachmon_asm.s

diff --git a/osfmk/ppc/vmachmon_asm.s b/osfmk/ppc/vmachmon_asm.s
index 1a4a673812557a7551522442f999af2bb1be17a0..3f8cac65423bcc02c91bb3b40961e6ec5056f12c 100644 (file)
--- a/osfmk/ppc/vmachmon_asm.s
+++ b/osfmk/ppc/vmachmon_asm.s
@@ -1,16 +1,19 @@
 /*
 /*

- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.

  *
  *

- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@

  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in

- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.

  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER


@@ -20,7 +23,7 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 

- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@

  */
 #include <assym.s>
 #include <debug.h>
  */
 #include <assym.s>
 #include <debug.h>


@@ -106,7 +109,9 @@ LEXT(vmm_dispatch_table)
                        .long   1                                                                                               ; Valid in Fam
                        .long   EXT(vmm_fam_reserved)                                                   ; Set guest register from Fam
                        .long   1                                                                                               ; Valid in Fam
                        .long   1                                                                                               ; Valid in Fam
                        .long   EXT(vmm_fam_reserved)                                                   ; Set guest register from Fam
                        .long   1                                                                                               ; Valid in Fam

-                       .long   EXT(vmm_set_XA)                                                                 ; Set extended architecture features for a VM 
+                       .long   EXT(vmm_activate_XA)                                                    ; Activate extended architecture features for a VM 
+                       .long   0                                                                                               ; Not valid in Fam
+                       .long   EXT(vmm_deactivate_XA)                                                  ; Deactivate extended architecture features for a VM 

                        .long   0                                                                                               ; Not valid in Fam
                        .long   EXT(vmm_get_XA)                                                                 ; Get extended architecture features from a VM 
                        .long   1                                                                                               ; Valid in Fam
                        .long   0                                                                                               ; Not valid in Fam
                        .long   EXT(vmm_get_XA)                                                                 ; Get extended architecture features from a VM 
                        .long   1                                                                                               ; Valid in Fam


@@ -130,8 +135,12 @@ LEXT(vmm_dispatch_table)
                        .long   1                                                                                               ; Valid in Fam
                        .long   EXT(vmm_max_addr)                                                               ; Returns the maximum virtual address 
                        .long   1                                                                                               ; Valid in Fam
                        .long   1                                                                                               ; Valid in Fam
                        .long   EXT(vmm_max_addr)                                                               ; Returns the maximum virtual address 
                        .long   1                                                                                               ; Valid in Fam

-
-
+#if 0
+                       .long   EXT(vmm_set_guest_memory)                                               ; Set guest memory extent
+                       .long   0                                                                                               ; Not valid in FAM
+                       .long   EXT(vmm_purge_local)                                                    ; Purge all local guest mappings */
+                       .long   1                                                                                               ; Valid in FAM
+#endif

                        .set    vmm_count,(.-EXT(vmm_dispatch_table))/8                 ; Get the top number
 
 
                        .set    vmm_count,(.-EXT(vmm_dispatch_table))/8                 ; Get the top number
 
 


@@ -151,7 +160,8 @@ LEXT(vmm_dispatch)
                        rlwinm  r11,r11,3,0,28                          ; Index into table
                        bge-    cr1,vmmBogus                            ; It is a bogus entry
                        add             r12,r10,r11                                     ; Get the vmm dispatch syscall entry
                        rlwinm  r11,r11,3,0,28                          ; Index into table
                        bge-    cr1,vmmBogus                            ; It is a bogus entry
                        add             r12,r10,r11                                     ; Get the vmm dispatch syscall entry

-                       mfsprg  r10,0                                           ; Get the per_proc
+                       mfsprg  r10,1                                           ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)           ; Get the per_proc block

                        lwz             r13,0(r12)                                      ; Get address of routine
                        lwz             r12,4(r12)                                      ; Get validity flag
                        lwz             r5,spcFlags(r10)                        ; Get per_proc special flags
                        lwz             r13,0(r12)                                      ; Get address of routine
                        lwz             r12,4(r12)                                      ; Get validity flag
                        lwz             r5,spcFlags(r10)                        ; Get per_proc special flags


@@ -181,8 +191,8 @@ vmmRetPt:   li              r0,0                                            ; Clear this out
                        b               EXT(ppcscret)                           ; Go back to handler...
                        
 vmmBogus:      
                        b               EXT(ppcscret)                           ; Go back to handler...
                        
 vmmBogus:      

-                       mfsprg  r10,0                                           ; Get the per_proc
-                       mfsprg  r3,1                                            ; Load current activation
+                       mfsprg  r3,1                                            ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r3)            ; Get the per_proc block

                        lwz             r5,spcFlags(r10)                        ; Get per_proc special flags
                        rlwinm. r5,r5,0,FamVMmodebit,FamVMmodebit       ; Test FamVMmodebit
                        bne             vmmexitcall                                     ; Do it to it           
                        lwz             r5,spcFlags(r10)                        ; Get per_proc special flags
                        rlwinm. r5,r5,0,FamVMmodebit,FamVMmodebit       ; Test FamVMmodebit
                        bne             vmmexitcall                                     ; Do it to it           


@@ -352,7 +362,8 @@ LEXT(vmm_execute_vm)
                        .globl  EXT(switchIntoVM)
 
 LEXT(switchIntoVM)
                        .globl  EXT(switchIntoVM)
 
 LEXT(switchIntoVM)

-                       mfsprg  r10,0                                           ; Get the per_proc
+                       mfsprg  r10,1                                           ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)           ; Get the per_proc block

                        rlwinm  r31,r4,24,24,31                         ; Get the address space
                        rlwinm  r4,r4,0,24,31                           ; Isolate the context id
                        lwz             r28,vmmControl(r3)                      ; Pick up the control table address
                        rlwinm  r31,r4,24,24,31                         ; Get the address space
                        rlwinm  r4,r4,0,24,31                           ; Isolate the context id
                        lwz             r28,vmmControl(r3)                      ; Pick up the control table address


@@ -521,7 +532,8 @@ swvmNoMap:  lwz             r20,vmmContextKern(r27)         ; Get the comm area
                        lwz             r17,vmmContextKern(r27)         ; Get the comm area back
                        la              r25,vmmFacCtx(r27)                      ; Point to the facility context
                        lwz             r15,vmmCntrl(r17)                       ; Get the control flags again
                        lwz             r17,vmmContextKern(r27)         ; Get the comm area back
                        la              r25,vmmFacCtx(r27)                      ; Point to the facility context
                        lwz             r15,vmmCntrl(r17)                       ; Get the control flags again

-                       mfsprg  r29,0                                           ; Get the per_proc
+                       mfsprg  r29,1                                           ; Get the current activation
+                       lwz             r29,ACT_PER_PROC(r29)           ; Get the per_proc block

                        
 ;
 ;                      Check if there is new floating point context to load
                        
 ;
 ;                      Check if there is new floating point context to load


@@ -539,11 +551,12 @@ swvmNoMap:        lwz             r20,vmmContextKern(r27)         ; Get the comm area
                        
                        eieio                                                           ; Make sure this stays in order
                        
                        
                        eieio                                                           ; Make sure this stays in order
                        

-                       lis             r18,hi16(EXT(per_proc_info))    ; Set base per_proc
-                       mulli   r19,r19,ppSize                          ; Find offset to the owner per_proc                     
-                       ori             r18,r18,lo16(EXT(per_proc_info))        ; Set base per_proc
+                       lis             r18,hi16(EXT(PerProcTable))     ; Set base PerProcTable
+                       mulli   r19,r19,ppeSize                         ; Find offset to the owner per_proc_entry
+                       ori             r18,r18,lo16(EXT(PerProcTable)) ; Set base PerProcTable

                        li              r16,FPUowner                            ; Displacement to float owner
                        li              r16,FPUowner                            ; Displacement to float owner

-                       add             r19,r18,r19                                     ; Point to the owner per_proc
+                       add             r19,r18,r19                                     ; Point to the owner per_proc_entry
+                       lwz             r19,ppe_vaddr(r19)                      ; Point to the owner per_proc

                        
 swvminvfpu:    lwarx   r18,r16,r19                                     ; Get the owner
 
                        
 swvminvfpu:    lwarx   r18,r16,r19                                     ; Get the owner
 


@@ -583,7 +596,8 @@ swvmGotFloat:
                        stw             r15,vmmCntrl(r17)                       ; Save the control flags sans vmmFloatLoad
                        rlwinm  r11,r11,0,floatCngbit+1,floatCngbit-1   ; Clear the changed bit here
                        lwz             r14,vmmStat(r17)                        ; Get the status flags
                        stw             r15,vmmCntrl(r17)                       ; Save the control flags sans vmmFloatLoad
                        rlwinm  r11,r11,0,floatCngbit+1,floatCngbit-1   ; Clear the changed bit here
                        lwz             r14,vmmStat(r17)                        ; Get the status flags

-                       mfsprg  r10,0                                           ; Get the per_proc
+                       mfsprg  r10,1                                           ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)           ; Get the per_proc block

                        stw             r11,ACT_MACT_SPF(r26)           ; Get the special flags
                        rlwinm  r14,r14,0,vmmFloatCngdb+1,vmmFloatCngdb-1       ; Clear the changed flag
                        stw             r11,spcFlags(r10)                       ; Set per_proc copy of the special flags
                        stw             r11,ACT_MACT_SPF(r26)           ; Get the special flags
                        rlwinm  r14,r14,0,vmmFloatCngdb+1,vmmFloatCngdb-1       ; Clear the changed flag
                        stw             r11,spcFlags(r10)                       ; Set per_proc copy of the special flags


@@ -605,11 +619,12 @@ swvmNoNewFloats:
                        
                        eieio                                                           ; Make sure this stays in order
                        
                        
                        eieio                                                           ; Make sure this stays in order
                        

-                       lis             r18,hi16(EXT(per_proc_info))    ; Set base per_proc
-                       mulli   r19,r19,ppSize                          ; Find offset to the owner per_proc                     
-                       ori             r18,r18,lo16(EXT(per_proc_info))        ; Set base per_proc
+                       lis             r18,hi16(EXT(PerProcTable))     ; Set base PerProcTable
+                       mulli   r19,r19,ppeSize                         ; Find offset to the owner per_proc_entry
+                       ori             r18,r18,lo16(EXT(PerProcTable)) ; Set base PerProcTable

                        li              r16,VMXowner                            ; Displacement to vector owner
                        li              r16,VMXowner                            ; Displacement to vector owner

-                       add             r19,r18,r19                                     ; Point to the owner per_proc   
+                       add             r19,r18,r19                                     ; Point to the owner per_proc_entry
+                       lwz             r19,ppe_vaddr(r19)                      ; Point to the owner per_proc

                        
 swvminvvec:    lwarx   r18,r16,r19                                     ; Get the owner
 
                        
 swvminvvec:    lwarx   r18,r16,r19                                     ; Get the owner
 


@@ -652,7 +667,8 @@ swvmGotVect:
                        rlwinm  r11,r11,0,vectorCngbit+1,vectorCngbit-1 ; Clear the changed bit here
                        stw             r8,savevrvalid(r21)                     ; Set the current VRSave as valid saved
                        lwz             r14,vmmStat(r17)                        ; Get the status flags
                        rlwinm  r11,r11,0,vectorCngbit+1,vectorCngbit-1 ; Clear the changed bit here
                        stw             r8,savevrvalid(r21)                     ; Set the current VRSave as valid saved
                        lwz             r14,vmmStat(r17)                        ; Get the status flags

-                       mfsprg  r10,0                                           ; Get the per_proc
+                       mfsprg  r10,1                                           ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)           ; Get the per_proc block

                        stw             r11,ACT_MACT_SPF(r26)           ; Get the special flags
                        rlwinm  r14,r14,0,vmmVectCngdb+1,vmmVectCngdb-1 ; Clear the changed flag
                        stw             r11,spcFlags(r10)                       ; Set per_proc copy of the special flags
                        stw             r11,ACT_MACT_SPF(r26)           ; Get the special flags
                        rlwinm  r14,r14,0,vmmVectCngdb+1,vmmVectCngdb-1 ; Clear the changed flag
                        stw             r11,spcFlags(r10)                       ; Set per_proc copy of the special flags


@@ -660,7 +676,7 @@ swvmGotVect:
                        
 swvmNoNewVects:                        
                        li              r3,1                                            ; Show normal exit with check for AST
                        
 swvmNoNewVects:                        
                        li              r3,1                                            ; Show normal exit with check for AST

-                       lwz             r16,ACT_THREAD(r26)                     ; Restore the thread pointer
+                       mr              r16,r26                 ; Restore the thread pointer

                        b               EXT(ppcscret)                           ; Go back to handler...
 
                        .align  5
                        b               EXT(ppcscret)                           ; Go back to handler...
 
                        .align  5


@@ -765,7 +781,8 @@ vmmexitcall:
                        stw             r0,vmmCEntry(r16)                       ; Clear pointer to active context
                        stw             r19,vmmFlags(r2)                        ; Set the status flags
                        rlwinm  r11,r11,0,userProtKeybit+1,userProtKeybit-1     ; Set back to normal protection key
                        stw             r0,vmmCEntry(r16)                       ; Clear pointer to active context
                        stw             r19,vmmFlags(r2)                        ; Set the status flags
                        rlwinm  r11,r11,0,userProtKeybit+1,userProtKeybit-1     ; Set back to normal protection key

-                       mfsprg  r10,0                                           ; Get the per_proc block
+                       mfsprg  r10,1                                           ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)           ; Get the per_proc block

                        rlwinm  r11,r11,0,FamVMenabit+1,FamVMenabit-1   ; Clear FamVMEnable
                        lwz             r18,spcFlags(r10)                       ; Get per_proc copy of the special flags
                        lwz             r5,vmmContextKern(r2)           ; Get the state page kernel addr 
                        rlwinm  r11,r11,0,FamVMenabit+1,FamVMenabit-1   ; Clear FamVMEnable
                        lwz             r18,spcFlags(r10)                       ; Get per_proc copy of the special flags
                        lwz             r5,vmmContextKern(r2)           ; Get the state page kernel addr 


@@ -831,7 +848,8 @@ LEXT(vmm_force_exit)
                        beq-    vfeNotRun                                       ; We were not in a vm....
                        rlwinm  r9,r9,0,userProtKeybit+1,userProtKeybit-1       ; Set back to normal protection key
                        stw             r0,vmmCEntry(r26)                       ; Clear pointer to active context
                        beq-    vfeNotRun                                       ; We were not in a vm....
                        rlwinm  r9,r9,0,userProtKeybit+1,userProtKeybit-1       ; Set back to normal protection key
                        stw             r0,vmmCEntry(r26)                       ; Clear pointer to active context

-                       mfsprg  r10,0                                           ; Get the per_proc block
+                       mfsprg  r10,1                                           ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)           ; Get the per_proc block

                        lwz             r18,spcFlags(r10)                       ; Get per_proc copy of the special flags
                        rlwinm  r9,r9,0,FamVMenabit+1,FamVMenabit-1     ; Clear Fam Enable
                        rlwinm  r9,r9,0,FamVMmodebit+1,FamVMmodebit-1   ; Clear Fam Enable
                        lwz             r18,spcFlags(r10)                       ; Get per_proc copy of the special flags
                        rlwinm  r9,r9,0,FamVMenabit+1,FamVMenabit-1     ; Clear Fam Enable
                        rlwinm  r9,r9,0,FamVMmodebit+1,FamVMmodebit-1   ; Clear Fam Enable


@@ -1211,7 +1229,7 @@ swap64:           lwz             r22,vmmXAFlgs(r27)                      ; Get the eXtended Architecture flags
                        lwz             r15,vmmppcpc(r5)                        ; First line of context 
                        lis             r22,hi16(MSR_IMPORT_BITS)       ; Get the MSR bits that are controllable by user
                        lwz             r23,vmmppcmsr(r5)                               
                        lwz             r15,vmmppcpc(r5)                        ; First line of context 
                        lis             r22,hi16(MSR_IMPORT_BITS)       ; Get the MSR bits that are controllable by user
                        lwz             r23,vmmppcmsr(r5)                               

-                       ori             r22,r25,lo16(MSR_IMPORT_BITS)   ; Get the rest of the MSR bits that are controllable by user
+                       ori             r22,r22,lo16(MSR_IMPORT_BITS)   ; Get the rest of the MSR bits that are controllable by user

                        lwz             r17,vmmppcr0(r5)                                
                        lwz             r18,vmmppcr1(r5)                
                        and             r23,r23,r22                                     ; Keep only the controllable bits               
                        lwz             r17,vmmppcr0(r5)                                
                        lwz             r18,vmmppcr1(r5)                
                        and             r23,r23,r22                                     ; Keep only the controllable bits               


@@ -1247,7 +1265,7 @@ sw64x1:           ld              r15,vmmppcXpc(r5)                       ; First line of context
                        lis             r22,hi16(MSR_IMPORT_BITS)       ; Get the MSR bits that are controllable by user (we will also allow 64-bit here)
                        sldi    r0,r0,63                                        ; Get 64-bit bit
                        ld              r23,vmmppcXmsr(r5)                              
                        lis             r22,hi16(MSR_IMPORT_BITS)       ; Get the MSR bits that are controllable by user (we will also allow 64-bit here)
                        sldi    r0,r0,63                                        ; Get 64-bit bit
                        ld              r23,vmmppcXmsr(r5)                              

-                       ori             r22,r25,lo16(MSR_IMPORT_BITS)   ; Get the rest of the MSR bits that are controllable by user
+                       ori             r22,r22,lo16(MSR_IMPORT_BITS)   ; Get the rest of the MSR bits that are controllable by user

                        ld              r17,vmmppcXr0(r5)               
                        or              r22,r22,r0                                      ; Add the 64-bit bit            
                        ld              r18,vmmppcXr1(r5)               
                        ld              r17,vmmppcXr0(r5)               
                        or              r22,r22,r0                                      ; Add the 64-bit bit            
                        ld              r18,vmmppcXr1(r5)               


@@ -1643,7 +1661,8 @@ sw64SC:           ld              r10,vmmppcXr6(r5)                       ; Get the fourth paramter
 ;
 
 vmmFamGuestResume:
 ;
 
 vmmFamGuestResume:

-                       mfsprg  r10,0                                                   ; Get the per_proc
+                       mfsprg  r10,1                                                   ; Get the current activation
+                       lwz             r10,ACT_PER_PROC(r10)                   ; Get the per_proc block

                        lwz             r27,vmmCEntry(r3)                               ; Get the context that is active
                        lwz             r4,VMMXAFlgs(r10)                               ; Get the eXtended Architecture flags                   
                        rlwinm. r4,r4,0,0,0                                             ; Are we doing a 64-bit virtual machine?                
                        lwz             r27,vmmCEntry(r3)                               ; Get the context that is active
                        lwz             r4,VMMXAFlgs(r10)                               ; Get the eXtended Architecture flags                   
                        rlwinm. r4,r4,0,0,0                                             ; Are we doing a 64-bit virtual machine?                


@@ -1741,7 +1760,7 @@ fgrXNoMap:
                        std             r7,saver7(r30)                                  ; Set savearea r7
 fgrret:
                        li              r3,1                                                    ; Show normal exit with check for AST
                        std             r7,saver7(r30)                                  ; Set savearea r7
 fgrret:
                        li              r3,1                                                    ; Show normal exit with check for AST

-                       lwz             r16,ACT_THREAD(r26)                             ; Restore the thread pointer
+                       mr              r16,r26                         ; Restore the thread pointer

                        b               EXT(ppcscret)                                   ; Go back to handler...
 
 ;
                        b               EXT(ppcscret)                                   ; Go back to handler...
 
 ;


@@ -2008,18 +2027,29 @@ fpfXret:
                        std             r2,savesrr0(r13)                                ; Store famhandler in srr0
                        blr
 
                        std             r2,savesrr0(r13)                                ; Store famhandler in srr0
                        blr
 

-;
-;                      Ultra Fast Path FAM syscalls
-;
+/*
+ *     Ultra Fast Path FAM syscalls
+ *
+ *     The UFT FAMs are those from kvmmResumeGuest to kvmmSetGuestRegister, inclusive.
+ *     We get here directly from the syscall vector, with interrupts and translation off,
+ *     64-bit mode on if supported, and all registers live except:
+ *
+ *     r13   = holds caller's cr
+ *     sprg2 = holds caller's r13
+ *     sprg3 = holds caller's r11
+ *     cr2   = set on (r3==kvmmSetGuestRegister)
+ *     cr5   = set on (r3==kvmmResumeGuest)
+ */

 
                        .align  5
                        .globl  EXT(vmm_ufp)
 
 LEXT(vmm_ufp)
                        mfsprg  r3,0                                                    ; Get the per_proc area
 
                        .align  5
                        .globl  EXT(vmm_ufp)
 
 LEXT(vmm_ufp)
                        mfsprg  r3,0                                                    ; Get the per_proc area

-                       mr              r11,r13                                                 ; Saved cr in r11
+                       mr              r11,r13                                                 ; Move saved cr to r11

                        lwz             r13,VMMXAFlgs(r3)                               ; Get the eXtended Architecture flags                   
                        lwz             r13,VMMXAFlgs(r3)                               ; Get the eXtended Architecture flags                   

-                       rlwinm. r13,r13,0,0,0                                           ; Are we doing a 64-bit virtual machine?                
+                       rlwinm. r13,r13,0,0,0                                   ; Are we doing a 64-bit virtual machine?                
+

                        lwz             r13,pfAvailable(r3)                             ; Get feature flags
                        mtcrf   0x02,r13                                                ; Put pf64Bitb etc in cr6
                        lwz             r13,VMMareaPhys(r3)                             ; Load fast assist area
                        lwz             r13,pfAvailable(r3)                             ; Get feature flags
                        mtcrf   0x02,r13                                                ; Put pf64Bitb etc in cr6
                        lwz             r13,VMMareaPhys(r3)                             ; Load fast assist area


@@ -2029,12 +2059,11 @@ LEXT(vmm_ufp)
 ufpVMareaPhys64:
                        sldi    r13,r13,12                                              ; Change ppnum to physical address
 ufpVMareaPhysret:
 ufpVMareaPhys64:
                        sldi    r13,r13,12                                              ; Change ppnum to physical address
 ufpVMareaPhysret:

-                       bne             ufpX
+                       bne             ufpX                                                    ; go handle a 64-bit virtual machine
+

                        bt              cr5_eq,ufpResumeGuest                   ; if kvmmResumeGuest, branch to ResumeGuest
                        bt              cr5_eq,ufpResumeGuest                   ; if kvmmResumeGuest, branch to ResumeGuest

-                       cmpwi   cr7,r4,0                                                ; Compare first arg with 0
-                       cmpwi   cr5,r4,7                                                ; Compare first arg with 7
-                       cror    cr1_eq,cr7_lt,cr5_gt                    ; Is it in 0 to 7 range
-                       beq             cr1,ufpVMret                                    ; Return if not in the range
+                       cmplwi  cr5,r4,7                                                ; First argument in range? (ie, 0-7)
+                       bgt             cr5,ufpVMret                                    ; Return if not in the range

                        slwi    r4,r4,2                                                 ; multiply index by 4
                        la              r3,famguestr0(r13)                              ; Load the base address
                        bt              cr2_eq,ufpSetGuestReg                   ; Set/get selector
                        slwi    r4,r4,2                                                 ; multiply index by 4
                        la              r3,famguestr0(r13)                              ; Load the base address
                        bt              cr2_eq,ufpSetGuestReg                   ; Set/get selector


@@ -2216,12 +2245,10 @@ ufpVMrfi64:
                        mfsprg  r11,3                                                   ; Restore R11
                        rfid
 
                        mfsprg  r11,3                                                   ; Restore R11
                        rfid
 

-ufpX:
+ufpX:                                               ; here if virtual machine is 64-bit

                        bt              cr5_eq,ufpXResumeGuest                  ; if kvmmResumeGuest, branch to ResumeGuest
                        bt              cr5_eq,ufpXResumeGuest                  ; if kvmmResumeGuest, branch to ResumeGuest

-                       cmpwi   cr7,r4,0                                                ; Compare first arg with 0
-                       cmpwi   cr5,r4,7                                                ; Compare first arg with 7
-                       cror    cr1_eq,cr7_lt,cr5_gt                    ; Is it in 0 to 7 range
-                       beq             cr1,ufpXVMret                                   ; Return if not in the range
+                       cmplwi  cr5,r4,7                                                ; Is first arg in range 0-7?
+                       bgt             cr5,ufpXVMret                                   ; Return if not in the range

                        slwi    r4,r4,3                                                 ; multiply index by 8
                        la              r3,famguestXr0(r13)                             ; Load the base address
                        bt              cr2_eq,ufpXSetGuestReg                  ; Set/get selector
                        slwi    r4,r4,3                                                 ; multiply index by 8
                        la              r3,famguestXr0(r13)                             ; Load the base address
                        bt              cr2_eq,ufpXSetGuestReg                  ; Set/get selector