KVM: VMX: restore MSR_IA32_DEBUGCTLMSR after VMEXIT

MSR_IA32_DEBUGCTLMSR is zeroed on VMEXIT. Restore it to the correct
value.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cc8ad98..d0f4bec 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6222,6 +6222,7 @@ 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;
 
        if (is_guest_mode(vcpu) && !vmx->nested.nested_run_pending) {
                struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
@@ -6261,6 +6262,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
                vmx_set_interrupt_shadow(vcpu, 0);
 
        atomic_switch_perf_msrs(vmx);
+       debugctlmsr = get_debugctlmsr();
 
        vmx->__launched = vmx->loaded_vmcs->launched;
        asm(
@@ -6362,6 +6364,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 #endif
              );
 
+       /* MSR_IA32_DEBUGCTLMSR is zeroed on vmexit. Restore it if needed */
+       if (debugctlmsr)
+               update_debugctlmsr(debugctlmsr);
+
 #ifndef CONFIG_X86_64
        /*
         * The sysexit path does not restore ds/es, so we must set them to