[apple/xnu.git] / osfmk / kern / hv_support.c

/*
 * Copyright (c) 2013 Apple 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
 * 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
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <kern/locks.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <libkern/OSAtomic.h>
#include <vm/vm_pageout.h>

#if defined(__x86_64__) && CONFIG_VMX
#include <i386/vmx/vmx_cpu.h>
#endif

#include <kern/hv_support.h>

int hv_support_available = 0;

/* callbacks for tasks/threads with associated hv objects */
hv_callbacks_t hv_callbacks = {
	.dispatch = NULL,		/* thread is being dispatched for execution */
	.preempt = NULL,		/* thread is being preempted */
	.suspend = NULL,		/* system is being suspended */
	.thread_destroy = NULL,	/* thread is being destroyed */
	.task_destroy = NULL,	/* task is being destroyed */
	.volatile_state = NULL,	/* thread state is becoming volatile */
};

/* trap tables for hv_*_trap syscalls */
static hv_trap_table_t hv_trap_table[] = {
	[HV_TASK_TRAP] = {
		.traps = NULL,
		.trap_count = 0
	},
	[HV_THREAD_TRAP] = {
		.traps = NULL,
		.trap_count = 0
	}
};

static int hv_callbacks_enabled = 0;
static lck_grp_t *hv_support_lck_grp = NULL;
static lck_mtx_t *hv_support_lck_mtx = NULL;

/* hv_support boot initialization */
void
hv_support_init(void) {
#if defined(__x86_64__) && CONFIG_VMX
	hv_support_available = vmx_hv_support();
#endif

	hv_support_lck_grp = lck_grp_alloc_init("hv_support", LCK_GRP_ATTR_NULL);
	assert(hv_support_lck_grp);

	hv_support_lck_mtx = lck_mtx_alloc_init(hv_support_lck_grp, LCK_ATTR_NULL);
	assert(hv_support_lck_mtx);
}

/* returns true if hv_support is available on this machine */
int
hv_get_support(void) {
	return hv_support_available;
}

/* associate an hv object with the current task */
void
hv_set_task_target(void *target) {
	current_task()->hv_task_target = target;
}

/* associate an hv object with the current thread */
void
hv_set_thread_target(void *target) {
	current_thread()->hv_thread_target = target;
}

/* get hv object associated with the current task */
void*
hv_get_task_target(void) {
	return current_task()->hv_task_target;
}

/* get hv object associated with the current thread */
void*
hv_get_thread_target(void) {
	return current_thread()->hv_thread_target;
}

/* test if a given thread state may be volatile between dispatch
   and preemption */
int
hv_get_volatile_state(hv_volatile_state_t state) {
	int is_volatile = 0;

#if (defined(__x86_64__))
	if (state == HV_DEBUG_STATE) {
		is_volatile = (current_thread()->machine.ids != NULL);
	}
#endif

	return is_volatile;
}

/* register a list of trap handlers for the hv_*_trap syscalls */
kern_return_t
hv_set_traps(hv_trap_type_t trap_type, const hv_trap_t *traps,
	unsigned trap_count)
{
	hv_trap_table_t *trap_table = &hv_trap_table[trap_type];
	kern_return_t kr = KERN_FAILURE;

	lck_mtx_lock(hv_support_lck_mtx);
	if (trap_table->trap_count == 0) {	
		trap_table->traps = traps;
		OSMemoryBarrier();
		trap_table->trap_count = trap_count;
		kr = KERN_SUCCESS;
	}
	lck_mtx_unlock(hv_support_lck_mtx);

	return kr;
}

/* release hv_*_trap traps */
void
hv_release_traps(hv_trap_type_t trap_type) {
	hv_trap_table_t *trap_table = &hv_trap_table[trap_type];

	lck_mtx_lock(hv_support_lck_mtx);
	trap_table->trap_count = 0;
	OSMemoryBarrier();
	trap_table->traps = NULL;
	lck_mtx_unlock(hv_support_lck_mtx);
}

/* register callbacks for certain task/thread events for tasks/threads with
   associated hv objects */
kern_return_t
hv_set_callbacks(hv_callbacks_t callbacks) {
	kern_return_t kr = KERN_FAILURE;

	lck_mtx_lock(hv_support_lck_mtx);
	if (hv_callbacks_enabled == 0) {	
		hv_callbacks = callbacks;
		hv_callbacks_enabled = 1;
		kr = KERN_SUCCESS;
	}
	lck_mtx_unlock(hv_support_lck_mtx);

	return kr;
}

/* release callbacks for task/thread events */
void
hv_release_callbacks(void) {
	lck_mtx_lock(hv_support_lck_mtx);	
	hv_callbacks = (hv_callbacks_t) {
		.dispatch = NULL,
		.preempt = NULL,
		.suspend = NULL,
		.thread_destroy = NULL,
		.task_destroy = NULL,
		.volatile_state = NULL,
		.memory_pressure = NULL
	};

	hv_callbacks_enabled = 0;
	lck_mtx_unlock(hv_support_lck_mtx);
}

/* system suspend notification */
void
hv_suspend(void) {
	if (hv_callbacks_enabled) {
		hv_callbacks.suspend();
	}
}

/* dispatch hv_task_trap/hv_thread_trap syscalls to trap handlers,
   fail for invalid index or absence of trap handlers, trap handler is
   responsible for validating targets */
#define HV_TRAP_DISPATCH(type, index, target, argument)\
	((__probable(index < hv_trap_table[type].trap_count)) ? \
		hv_trap_table[type].traps[index](target, argument) \
			: KERN_INVALID_ARGUMENT)

kern_return_t hv_task_trap(uint64_t index, uint64_t arg) {
	return HV_TRAP_DISPATCH(HV_TASK_TRAP, index, hv_get_task_target(), arg);
}

kern_return_t hv_thread_trap(uint64_t index, uint64_t arg) {
	return HV_TRAP_DISPATCH(HV_THREAD_TRAP, index, hv_get_thread_target(), arg);
}
Commit	Line	Data
fe8ab488 A	1	/*
	2	* Copyright (c) 2013 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29	#include <kern/locks.h>
	30	#include <kern/task.h>
	31	#include <kern/thread.h>
	32	#include <libkern/OSAtomic.h>
	33	#include <vm/vm_pageout.h>
	34
	35	#if defined(__x86_64__) && CONFIG_VMX
	36	#include <i386/vmx/vmx_cpu.h>
	37	#endif
	38
	39	#include <kern/hv_support.h>
	40
	41	int hv_support_available = 0;
	42
	43	/* callbacks for tasks/threads with associated hv objects */
	44	hv_callbacks_t hv_callbacks = {
	45	.dispatch = NULL, /* thread is being dispatched for execution */
	46	.preempt = NULL, /* thread is being preempted */
04b8595b	47	.suspend = NULL, /* system is being suspended */
fe8ab488 A	48	.thread_destroy = NULL, /* thread is being destroyed */
	49	.task_destroy = NULL, /* task is being destroyed */
	50	.volatile_state = NULL, /* thread state is becoming volatile */
fe8ab488 A	51	};
	52
	53	/* trap tables for hv__trap syscalls /
	54	static hv_trap_table_t hv_trap_table[] = {
	55	[HV_TASK_TRAP] = {
	56	.traps = NULL,
	57	.trap_count = 0
	58	},
	59	[HV_THREAD_TRAP] = {
	60	.traps = NULL,
	61	.trap_count = 0
	62	}
	63	};
	64
	65	static int hv_callbacks_enabled = 0;
fe8ab488 A	66	static lck_grp_t *hv_support_lck_grp = NULL;
fe8ab488 A	67	static lck_mtx_t *hv_support_lck_mtx = NULL;
fe8ab488 A	68
	69	/* hv_support boot initialization */
	70	void
	71	hv_support_init(void) {
	72	#if defined(__x86_64__) && CONFIG_VMX
	73	hv_support_available = vmx_hv_support();
	74	#endif
	75
	76	hv_support_lck_grp = lck_grp_alloc_init("hv_support", LCK_GRP_ATTR_NULL);
	77	assert(hv_support_lck_grp);
	78
	79	hv_support_lck_mtx = lck_mtx_alloc_init(hv_support_lck_grp, LCK_ATTR_NULL);
	80	assert(hv_support_lck_mtx);
	81	}
	82
	83	/* returns true if hv_support is available on this machine */
	84	int
	85	hv_get_support(void) {
	86	return hv_support_available;
	87	}
	88
	89	/* associate an hv object with the current task */
	90	void
	91	hv_set_task_target(void *target) {
	92	current_task()->hv_task_target = target;
	93	}
	94
	95	/* associate an hv object with the current thread */
	96	void
	97	hv_set_thread_target(void *target) {
	98	current_thread()->hv_thread_target = target;
	99	}
	100
	101	/* get hv object associated with the current task */
	102	void*
	103	hv_get_task_target(void) {
	104	return current_task()->hv_task_target;
	105	}
	106
	107	/* get hv object associated with the current thread */
	108	void*
	109	hv_get_thread_target(void) {
	110	return current_thread()->hv_thread_target;
	111	}
	112
	113	/* test if a given thread state may be volatile between dispatch
	114	and preemption */
	115	int
	116	hv_get_volatile_state(hv_volatile_state_t state) {
	117	int is_volatile = 0;
	118
	119	#if (defined(__x86_64__))
	120	if (state == HV_DEBUG_STATE) {
	121	is_volatile = (current_thread()->machine.ids != NULL);
	122	}
	123	#endif
	124
	125	return is_volatile;
	126	}
	127
fe8ab488 A	128	/* register a list of trap handlers for the hv__trap syscalls /
	129	kern_return_t
	130	hv_set_traps(hv_trap_type_t trap_type, const hv_trap_t *traps,
	131	unsigned trap_count)
	132	{
	133	hv_trap_table_t *trap_table = &hv_trap_table[trap_type];
	134	kern_return_t kr = KERN_FAILURE;
	135
	136	lck_mtx_lock(hv_support_lck_mtx);
	137	if (trap_table->trap_count == 0) {
	138	trap_table->traps = traps;
	139	OSMemoryBarrier();
	140	trap_table->trap_count = trap_count;
	141	kr = KERN_SUCCESS;
	142	}
	143	lck_mtx_unlock(hv_support_lck_mtx);
	144
	145	return kr;
	146	}
	147
	148	/* release hv__trap traps /
	149	void
	150	hv_release_traps(hv_trap_type_t trap_type) {
	151	hv_trap_table_t *trap_table = &hv_trap_table[trap_type];
	152
	153	lck_mtx_lock(hv_support_lck_mtx);
	154	trap_table->trap_count = 0;
	155	OSMemoryBarrier();
	156	trap_table->traps = NULL;
	157	lck_mtx_unlock(hv_support_lck_mtx);
	158	}
	159
	160	/* register callbacks for certain task/thread events for tasks/threads with
	161	associated hv objects */
	162	kern_return_t
	163	hv_set_callbacks(hv_callbacks_t callbacks) {
	164	kern_return_t kr = KERN_FAILURE;
	165
	166	lck_mtx_lock(hv_support_lck_mtx);
	167	if (hv_callbacks_enabled == 0) {
	168	hv_callbacks = callbacks;
	169	hv_callbacks_enabled = 1;
	170	kr = KERN_SUCCESS;
	171	}
	172	lck_mtx_unlock(hv_support_lck_mtx);
	173
	174	return kr;
	175	}
	176
	177	/* release callbacks for task/thread events */
	178	void
	179	hv_release_callbacks(void) {
	180	lck_mtx_lock(hv_support_lck_mtx);
	181	hv_callbacks = (hv_callbacks_t) {
	182	.dispatch = NULL,
	183	.preempt = NULL,
04b8595b	184	.suspend = NULL,
fe8ab488 A	185	.thread_destroy = NULL,
	186	.task_destroy = NULL,
	187	.volatile_state = NULL,
	188	.memory_pressure = NULL
	189	};
	190
	191	hv_callbacks_enabled = 0;
	192	lck_mtx_unlock(hv_support_lck_mtx);
	193	}
	194
04b8595b A	195	/* system suspend notification */
	196	void
	197	hv_suspend(void) {
	198	if (hv_callbacks_enabled) {
	199	hv_callbacks.suspend();
	200	}
	201	}
	202
fe8ab488 A	203	/* dispatch hv_task_trap/hv_thread_trap syscalls to trap handlers,
	204	fail for invalid index or absence of trap handlers, trap handler is
	205	responsible for validating targets */
	206	#define HV_TRAP_DISPATCH(type, index, target, argument)\
	207	((__probable(index < hv_trap_table[type].trap_count)) ? \
	208	hv_trap_table[type].traps[index](target, argument) \
	209	: KERN_INVALID_ARGUMENT)
	210
	211	kern_return_t hv_task_trap(uint64_t index, uint64_t arg) {
	212	return HV_TRAP_DISPATCH(HV_TASK_TRAP, index, hv_get_task_target(), arg);
	213	}
	214
	215	kern_return_t hv_thread_trap(uint64_t index, uint64_t arg) {
	216	return HV_TRAP_DISPATCH(HV_THREAD_TRAP, index, hv_get_thread_target(), arg);
	217	}