linux/drivers/kvm/x86.c
Carsten Otte 043405e100 KVM: Move x86 msr handling to new files x86.[ch]
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30 17:52:51 +02:00

103 lines
2.2 KiB
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();
}