blob: 1fe209dd4caf18df2db0c1d16eb22e880d1a6cf4 [file] [log] [blame]
/*
* 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 "kvm.h"
#include "x86.h"
#include "irq.h"
#include <linux/kvm.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <asm/uaccess.h>
#define MAX_IO_MSRS 256
/*
* 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,
};
/*
* Adapt set_msr() to msr_io()'s calling convention
*/
static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
return kvm_set_msr(vcpu, index, *data);
}
/*
* Read or write a bunch of msrs. All parameters are kernel addresses.
*
* @return number of msrs set successfully.
*/
static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
struct kvm_msr_entry *entries,
int (*do_msr)(struct kvm_vcpu *vcpu,
unsigned index, u64 *data))
{
int i;
vcpu_load(vcpu);
for (i = 0; i < msrs->nmsrs; ++i)
if (do_msr(vcpu, entries[i].index, &entries[i].data))
break;
vcpu_put(vcpu);
return i;
}
/*
* Read or write a bunch of msrs. Parameters are user addresses.
*
* @return number of msrs set successfully.
*/
static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
int (*do_msr)(struct kvm_vcpu *vcpu,
unsigned index, u64 *data),
int writeback)
{
struct kvm_msrs msrs;
struct kvm_msr_entry *entries;
int r, n;
unsigned size;
r = -EFAULT;
if (copy_from_user(&msrs, user_msrs, sizeof msrs))
goto out;
r = -E2BIG;
if (msrs.nmsrs >= MAX_IO_MSRS)
goto out;
r = -ENOMEM;
size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
entries = vmalloc(size);
if (!entries)
goto out;
r = -EFAULT;
if (copy_from_user(entries, user_msrs->entries, size))
goto out_free;
r = n = __msr_io(vcpu, &msrs, entries, do_msr);
if (r < 0)
goto out_free;
r = -EFAULT;
if (writeback && copy_to_user(user_msrs->entries, entries, size))
goto out_free;
r = n;
out_free:
vfree(entries);
out:
return r;
}
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;
}
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
kvm_x86_ops->vcpu_load(vcpu, cpu);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->vcpu_put(vcpu);
}
static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
{
u64 efer;
int i;
struct kvm_cpuid_entry *e, *entry;
rdmsrl(MSR_EFER, efer);
entry = NULL;
for (i = 0; i < vcpu->cpuid_nent; ++i) {
e = &vcpu->cpuid_entries[i];
if (e->function == 0x80000001) {
entry = e;
break;
}
}
if (entry && (entry->edx & (1 << 20)) && !(efer & EFER_NX)) {
entry->edx &= ~(1 << 20);
printk(KERN_INFO "kvm: guest NX capability removed\n");
}
}
static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
struct kvm_cpuid *cpuid,
struct kvm_cpuid_entry __user *entries)
{
int r;
r = -E2BIG;
if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
goto out;
r = -EFAULT;
if (copy_from_user(&vcpu->cpuid_entries, entries,
cpuid->nent * sizeof(struct kvm_cpuid_entry)))
goto out;
vcpu->cpuid_nent = cpuid->nent;
cpuid_fix_nx_cap(vcpu);
return 0;
out:
return r;
}
static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
vcpu_load(vcpu);
memcpy(s->regs, vcpu->apic->regs, sizeof *s);
vcpu_put(vcpu);
return 0;
}
static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
struct kvm_lapic_state *s)
{
vcpu_load(vcpu);
memcpy(vcpu->apic->regs, s->regs, sizeof *s);
kvm_apic_post_state_restore(vcpu);
vcpu_put(vcpu);
return 0;
}
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
int r;
switch (ioctl) {
case KVM_GET_LAPIC: {
struct kvm_lapic_state lapic;
memset(&lapic, 0, sizeof lapic);
r = kvm_vcpu_ioctl_get_lapic(vcpu, &lapic);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &lapic, sizeof lapic))
goto out;
r = 0;
break;
}
case KVM_SET_LAPIC: {
struct kvm_lapic_state lapic;
r = -EFAULT;
if (copy_from_user(&lapic, argp, sizeof lapic))
goto out;
r = kvm_vcpu_ioctl_set_lapic(vcpu, &lapic);;
if (r)
goto out;
r = 0;
break;
}
case KVM_SET_CPUID: {
struct kvm_cpuid __user *cpuid_arg = argp;
struct kvm_cpuid cpuid;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
goto out;
r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries);
if (r)
goto out;
break;
}
case KVM_GET_MSRS:
r = msr_io(vcpu, argp, kvm_get_msr, 1);
break;
case KVM_SET_MSRS:
r = msr_io(vcpu, argp, do_set_msr, 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();
}