KVM: nVMX: Add VM-Enter failed tracepoints for super early checks

Add tracepoints for the early consistency checks in nested_vmx_run().
The "VMLAUNCH vs. VMRESUME" check in particular is useful to trace, as
there is no architectural way to check VMCS.LAUNCH_STATE, and subtle
bugs such as VMCLEAR on the wrong HPA can lead to confusing errors in
the L1 VMM.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200812180615.22372-1-sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f39491c..473fa40 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3471,11 +3471,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
        if (evmptrld_status == EVMPTRLD_ERROR) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
-       } else if (evmptrld_status == EVMPTRLD_VMFAIL) {
+       } else if (CC(evmptrld_status == EVMPTRLD_VMFAIL)) {
                return nested_vmx_failInvalid(vcpu);
        }
 
-       if (!vmx->nested.hv_evmcs && vmx->nested.current_vmptr == -1ull)
+       if (CC(!vmx->nested.hv_evmcs && vmx->nested.current_vmptr == -1ull))
                return nested_vmx_failInvalid(vcpu);
 
        vmcs12 = get_vmcs12(vcpu);
@@ -3486,7 +3486,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
         * rather than RFLAGS.ZF, and no error number is stored to the
         * VM-instruction error field.
         */
-       if (vmcs12->hdr.shadow_vmcs)
+       if (CC(vmcs12->hdr.shadow_vmcs))
                return nested_vmx_failInvalid(vcpu);
 
        if (vmx->nested.hv_evmcs) {
@@ -3507,10 +3507,10 @@ 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)
+       if (CC(interrupt_shadow & KVM_X86_SHADOW_INT_MOV_SS))
                return nested_vmx_fail(vcpu, VMXERR_ENTRY_EVENTS_BLOCKED_BY_MOV_SS);
 
-       if (vmcs12->launch_state == launch)
+       if (CC(vmcs12->launch_state == launch))
                return nested_vmx_fail(vcpu,
                        launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS
                               : VMXERR_VMRESUME_NONLAUNCHED_VMCS);