KVM: VMX: Use vmx_interrupt_blocked() directly from vmx_handle_exit()

Use vmx_interrupt_blocked() instead of bouncing through
vmx_interrupt_allowed() when handling edge cases in vmx_handle_exit().
The nested_run_pending check in vmx_interrupt_allowed() should never
evaluate true in the VM-Exit path.

Hoist the WARN in handle_invalid_guest_state() up to vmx_handle_exit()
to enforce the above assumption for the !enable_vnmi case, and to detect
any other potential bugs with nested VM-Enter.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-12-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2020-04-22 19:25:48 -07:00 committed by Paolo Bonzini
parent 3b82b8d7fd
commit db43859280

View File

@ -5285,18 +5285,11 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
bool intr_window_requested;
unsigned count = 130;
/*
* We should never reach the point where we are emulating L2
* due to invalid guest state as that means we incorrectly
* allowed a nested VMEntry with an invalid vmcs12.
*/
WARN_ON_ONCE(vmx->emulation_required && vmx->nested.nested_run_pending);
intr_window_requested = exec_controls_get(vmx) &
CPU_BASED_INTR_WINDOW_EXITING;
while (vmx->emulation_required && count-- != 0) {
if (intr_window_requested && vmx_interrupt_allowed(vcpu))
if (intr_window_requested && !vmx_interrupt_blocked(vcpu))
return handle_interrupt_window(&vmx->vcpu);
if (kvm_test_request(KVM_REQ_EVENT, vcpu))
@ -5913,6 +5906,14 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu,
if (enable_pml)
vmx_flush_pml_buffer(vcpu);
/*
* We should never reach this point with a pending nested VM-Enter, and
* more specifically emulation of L2 due to invalid guest state (see
* below) should never happen as that means we incorrectly allowed a
* nested VM-Enter with an invalid vmcs12.
*/
WARN_ON_ONCE(vmx->nested.nested_run_pending);
/* If guest state is invalid, start emulating */
if (vmx->emulation_required)
return handle_invalid_guest_state(vcpu);
@ -5979,7 +5980,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu,
if (unlikely(!enable_vnmi &&
vmx->loaded_vmcs->soft_vnmi_blocked)) {
if (vmx_interrupt_allowed(vcpu)) {
if (!vmx_interrupt_blocked(vcpu)) {
vmx->loaded_vmcs->soft_vnmi_blocked = 0;
} else if (vmx->loaded_vmcs->vnmi_blocked_time > 1000000000LL &&
vcpu->arch.nmi_pending) {