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-rw-r--r--arch/x86/kvm/vmx.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index de426887b359..80c22a3ca688 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -441,6 +441,7 @@ struct vcpu_vmx {
#endif
int gs_ldt_reload_needed;
int fs_reload_needed;
+ unsigned long vmcs_host_cr4; /* May not match real cr4 */
} host_state;
struct {
int vm86_active;
@@ -4165,11 +4166,16 @@ static void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
u32 low32, high32;
unsigned long tmpl;
struct desc_ptr dt;
+ unsigned long cr4;
vmcs_writel(HOST_CR0, read_cr0() & ~X86_CR0_TS); /* 22.2.3 */
- vmcs_writel(HOST_CR4, read_cr4()); /* 22.2.3, 22.2.5 */
vmcs_writel(HOST_CR3, read_cr3()); /* 22.2.3 FIXME: shadow tables */
+ /* Save the most likely value for this task's CR4 in the VMCS. */
+ cr4 = read_cr4();
+ vmcs_writel(HOST_CR4, cr4); /* 22.2.3, 22.2.5 */
+ vmx->host_state.vmcs_host_cr4 = cr4;
+
vmcs_write16(HOST_CS_SELECTOR, __KERNEL_CS); /* 22.2.4 */
#ifdef CONFIG_X86_64
/*
@@ -7196,7 +7202,7 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
- unsigned long debugctlmsr;
+ unsigned long debugctlmsr, cr4;
/* Record the guest's net vcpu time for enforced NMI injections. */
if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked))
@@ -7217,6 +7223,12 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (test_bit(VCPU_REGS_RIP, (unsigned long *)&vcpu->arch.regs_dirty))
vmcs_writel(GUEST_RIP, vcpu->arch.regs[VCPU_REGS_RIP]);
+ cr4 = read_cr4();
+ if (unlikely(cr4 != vmx->host_state.vmcs_host_cr4)) {
+ vmcs_writel(HOST_CR4, cr4);
+ vmx->host_state.vmcs_host_cr4 = cr4;
+ }
+
/* When single-stepping over STI and MOV SS, we must clear the
* corresponding interruptibility bits in the guest state. Otherwise
* vmentry fails as it then expects bit 14 (BS) in pending debug