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Diffstat (limited to 'drivers/kvm')
-rw-r--r--drivers/kvm/vmx.c58
1 files changed, 42 insertions, 16 deletions
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 3745e6ccc5b..6270df58e05 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -80,6 +80,9 @@ static const u32 vmx_msr_index[] = {
#ifdef CONFIG_X86_64
static unsigned msr_offset_kernel_gs_base;
+#define NR_64BIT_MSRS 4
+#else
+#define NR_64BIT_MSRS 0
#endif
static inline int is_page_fault(u32 intr_info)
@@ -301,6 +304,32 @@ static void vmx_inject_gp(struct kvm_vcpu *vcpu, unsigned error_code)
}
/*
+ * Set up the vmcs to automatically save and restore system
+ * msrs. Don't touch the 64-bit msrs if the guest is in legacy
+ * mode, as fiddling with msrs is very expensive.
+ */
+static void setup_msrs(struct kvm_vcpu *vcpu)
+{
+ int nr_skip, nr_good_msrs;
+
+ if (is_long_mode(vcpu))
+ nr_skip = NR_BAD_MSRS;
+ else
+ nr_skip = NR_64BIT_MSRS;
+ nr_good_msrs = vcpu->nmsrs - nr_skip;
+
+ vmcs_writel(VM_ENTRY_MSR_LOAD_ADDR,
+ virt_to_phys(vcpu->guest_msrs + nr_skip));
+ vmcs_writel(VM_EXIT_MSR_STORE_ADDR,
+ virt_to_phys(vcpu->guest_msrs + nr_skip));
+ vmcs_writel(VM_EXIT_MSR_LOAD_ADDR,
+ virt_to_phys(vcpu->host_msrs + nr_skip));
+ vmcs_write32(VM_EXIT_MSR_STORE_COUNT, nr_good_msrs); /* 22.2.2 */
+ vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
+ vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
+}
+
+/*
* reads and returns guest's timestamp counter "register"
* guest_tsc = host_tsc + tsc_offset -- 21.3
*/
@@ -825,6 +854,7 @@ static void vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer)
msr->data = efer & ~EFER_LME;
}
+ setup_msrs(vcpu);
}
#endif
@@ -988,7 +1018,6 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
struct descriptor_table dt;
int i;
int ret = 0;
- int nr_good_msrs;
extern asmlinkage void kvm_vmx_return(void);
if (!init_rmode_tss(vcpu->kvm)) {
@@ -1140,19 +1169,10 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
++vcpu->nmsrs;
}
- nr_good_msrs = vcpu->nmsrs - NR_BAD_MSRS;
- vmcs_writel(VM_ENTRY_MSR_LOAD_ADDR,
- virt_to_phys(vcpu->guest_msrs + NR_BAD_MSRS));
- vmcs_writel(VM_EXIT_MSR_STORE_ADDR,
- virt_to_phys(vcpu->guest_msrs + NR_BAD_MSRS));
- vmcs_writel(VM_EXIT_MSR_LOAD_ADDR,
- virt_to_phys(vcpu->host_msrs + NR_BAD_MSRS));
+ setup_msrs(vcpu);
+
vmcs_write32_fixedbits(MSR_IA32_VMX_EXIT_CTLS, VM_EXIT_CONTROLS,
(HOST_IS_64 << 9)); /* 22.2,1, 20.7.1 */
- vmcs_write32(VM_EXIT_MSR_STORE_COUNT, nr_good_msrs); /* 22.2.2 */
- vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
- vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, nr_good_msrs); /* 22.2.2 */
-
/* 22.2.1, 20.8.1 */
vmcs_write32_fixedbits(MSR_IA32_VMX_ENTRY_CTLS,
@@ -1769,9 +1789,11 @@ again:
fx_restore(vcpu->guest_fx_image);
#ifdef CONFIG_X86_64
- save_msrs(vcpu->host_msrs + msr_offset_kernel_gs_base, 1);
+ if (is_long_mode(vcpu)) {
+ save_msrs(vcpu->host_msrs + msr_offset_kernel_gs_base, 1);
+ load_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
+ }
#endif
- load_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
asm (
/* Store host registers */
@@ -1915,8 +1937,12 @@ again:
}
++kvm_stat.exits;
- save_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
- load_msrs(vcpu->host_msrs, NR_BAD_MSRS);
+#ifdef CONFIG_X86_64
+ if (is_long_mode(vcpu)) {
+ save_msrs(vcpu->guest_msrs, NR_BAD_MSRS);
+ load_msrs(vcpu->host_msrs, NR_BAD_MSRS);
+ }
+#endif
fx_save(vcpu->guest_fx_image);
fx_restore(vcpu->host_fx_image);