[net-next-2.6.git] / drivers / kvm / x86.c

/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * derived from drivers/kvm/kvm_main.c
 *
 * Copyright (C) 2006 Qumranet, Inc.
 *
 * Authors:
 *   Avi Kivity   <avi@qumranet.com>
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "x86.h"

#include <asm/uaccess.h>

/*
 * List of msr numbers which we expose to userspace through KVM_GET_MSRS
 * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
 *
 * This list is modified at module load time to reflect the
 * capabilities of the host cpu.
 */
static u32 msrs_to_save[] = {
	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
	MSR_K6_STAR,
#ifdef CONFIG_X86_64
	MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
	MSR_IA32_TIME_STAMP_COUNTER,
};

static unsigned num_msrs_to_save;

static u32 emulated_msrs[] = {
	MSR_IA32_MISC_ENABLE,
};

long kvm_arch_dev_ioctl(struct file *filp,
			unsigned int ioctl, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	long r;

	switch (ioctl) {
	case KVM_GET_MSR_INDEX_LIST: {
		struct kvm_msr_list __user *user_msr_list = argp;
		struct kvm_msr_list msr_list;
		unsigned n;

		r = -EFAULT;
		if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
			goto out;
		n = msr_list.nmsrs;
		msr_list.nmsrs = num_msrs_to_save + ARRAY_SIZE(emulated_msrs);
		if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
			goto out;
		r = -E2BIG;
		if (n < num_msrs_to_save)
			goto out;
		r = -EFAULT;
		if (copy_to_user(user_msr_list->indices, &msrs_to_save,
				 num_msrs_to_save * sizeof(u32)))
			goto out;
		if (copy_to_user(user_msr_list->indices
				 + num_msrs_to_save * sizeof(u32),
				 &emulated_msrs,
				 ARRAY_SIZE(emulated_msrs) * sizeof(u32)))
			goto out;
		r = 0;
		break;
	}
	default:
		r = -EINVAL;
	}
out:
	return r;
}

static __init void kvm_init_msr_list(void)
{
	u32 dummy[2];
	unsigned i, j;

	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
		if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
			continue;
		if (j < i)
			msrs_to_save[j] = msrs_to_save[i];
		j++;
	}
	num_msrs_to_save = j;
}

__init void kvm_arch_init(void)
{
	kvm_init_msr_list();
}
Commit	Line	Data
043405e1 CO	1	/*
	2	* Kernel-based Virtual Machine driver for Linux
	3	*
	4	* derived from drivers/kvm/kvm_main.c
	5	*
	6	* Copyright (C) 2006 Qumranet, Inc.
	7	*
	8	* Authors:
	9	* Avi Kivity <avi@qumranet.com>
	10	* Yaniv Kamay <yaniv@qumranet.com>
	11	*
	12	* This work is licensed under the terms of the GNU GPL, version 2. See
	13	* the COPYING file in the top-level directory.
	14	*
	15	*/
	16
	17	#include "x86.h"
	18
	19	#include <asm/uaccess.h>
	20
	21	/*
	22	* List of msr numbers which we expose to userspace through KVM_GET_MSRS
	23	* and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
	24	*
	25	* This list is modified at module load time to reflect the
	26	* capabilities of the host cpu.
	27	*/
	28	static u32 msrs_to_save[] = {
	29	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
	30	MSR_K6_STAR,
	31	#ifdef CONFIG_X86_64
	32	MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
	33	#endif
	34	MSR_IA32_TIME_STAMP_COUNTER,
	35	};
	36
	37	static unsigned num_msrs_to_save;
	38
	39	static u32 emulated_msrs[] = {
	40	MSR_IA32_MISC_ENABLE,
	41	};
	42
	43	long kvm_arch_dev_ioctl(struct file *filp,
	44	unsigned int ioctl, unsigned long arg)
	45	{
	46	void __user argp = (void __user )arg;
	47	long r;
	48
	49	switch (ioctl) {
	50	case KVM_GET_MSR_INDEX_LIST: {
	51	struct kvm_msr_list __user *user_msr_list = argp;
	52	struct kvm_msr_list msr_list;
	53	unsigned n;
	54
	55	r = -EFAULT;
	56	if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
	57	goto out;
	58	n = msr_list.nmsrs;
	59	msr_list.nmsrs = num_msrs_to_save + ARRAY_SIZE(emulated_msrs);
	60	if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
	61	goto out;
	62	r = -E2BIG;
	63	if (n < num_msrs_to_save)
	64	goto out;
65	r = -EFAULT;
66	if (copy_to_user(user_msr_list->indices, &msrs_to_save,
67	num_msrs_to_save * sizeof(u32)))
68	goto out;
69	if (copy_to_user(user_msr_list->indices
70	+ num_msrs_to_save * sizeof(u32),
71	&emulated_msrs,
72	ARRAY_SIZE(emulated_msrs) * sizeof(u32)))
73	goto out;
74	r = 0;
75	break;
76	}
77	default:
78	r = -EINVAL;
79	}
80	out:
81	return r;
82	}
83
84	static __init void kvm_init_msr_list(void)
85	{
86	u32 dummy[2];
87	unsigned i, j;
88
89	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
90	if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
91	continue;
92	if (j < i)
93	msrs_to_save[j] = msrs_to_save[i];
94	j++;
95	}
96	num_msrs_to_save = j;
97	}
98
99	__init void kvm_arch_init(void)
100	{
101	kvm_init_msr_list();
102	}