KVM: nVMX: Disallow VM-entry in MOV-SS shadow

Immediately following MOV-to-SS/POP-to-SS, VM-entry is
disallowed. This check comes after the check for a valid VMCS. When
this check fails, the instruction pointer should fall through to the
next instruction, the ALU flags should be set to indicate VMfailValid,
and the VM-instruction error should be set to 26 ("VM entry with
events blocked by MOV SS").

Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a0c472bcb2a2fa0753da056033fbf335e32d1795..791c018a0034379bd75ccae5fd7e566d17fc9e3f 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10492,6 +10492,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 {
        struct vmcs12 *vmcs12;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
+       u32 interrupt_shadow = vmx_get_interrupt_shadow(vcpu);
        u32 exit_qual;
        int ret;
 
@@ -10516,6 +10517,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
         * for misconfigurations which will anyway be caught by the processor
         * when using the merged vmcs02.
         */
+       if (interrupt_shadow & KVM_X86_SHADOW_INT_MOV_SS) {
+               nested_vmx_failValid(vcpu,
+                                    VMXERR_ENTRY_EVENTS_BLOCKED_BY_MOV_SS);
+               goto out;
+       }
+
        if (vmcs12->launch_state == launch) {
                nested_vmx_failValid(vcpu,
                        launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS