diff options
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/vmx.c | 58 |
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); |