diff options
| author | Sean Christopherson <seanjc@google.com> | 2022-08-30 23:16:02 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-09-26 12:03:08 -0400 |
| commit | 72c14e00bdc445e96045c28d04bba45cbe69cf95 (patch) | |
| tree | a0a866ce68b2da420ec9b9fe14a8b8b4ec5aaf27 /arch/x86/kvm/vmx/nested.c | |
| parent | d4963e319f1f7851a098df6610a27f9f4cf6d42a (diff) | |
| download | linux-72c14e00bdc445e96045c28d04bba45cbe69cf95.tar.bz2 | |
KVM: x86: Formalize blocking of nested pending exceptions
Capture nested_run_pending as block_pending_exceptions so that the logic
of why exceptions are blocked only needs to be documented once instead of
at every place that employs the logic.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20220830231614.3580124-16-seanjc@google.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/nested.c')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 8e7f8cebce4d..68533ae52d90 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3945,11 +3945,23 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu) static int vmx_check_nested_events(struct kvm_vcpu *vcpu) { + struct kvm_lapic *apic = vcpu->arch.apic; struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long exit_qual; - bool block_nested_events = - vmx->nested.nested_run_pending || kvm_event_needs_reinjection(vcpu); - struct kvm_lapic *apic = vcpu->arch.apic; + /* + * Only a pending nested run blocks a pending exception. If there is a + * previously injected event, the pending exception occurred while said + * event was being delivered and thus needs to be handled. + */ + bool block_nested_exceptions = vmx->nested.nested_run_pending; + /* + * New events (not exceptions) are only recognized at instruction + * boundaries. If an event needs reinjection, then KVM is handling a + * VM-Exit that occurred _during_ instruction execution; new events are + * blocked until the instruction completes. + */ + bool block_nested_events = block_nested_exceptions || + kvm_event_needs_reinjection(vcpu); if (lapic_in_kernel(vcpu) && test_bit(KVM_APIC_INIT, &apic->pending_events)) { @@ -3988,15 +4000,10 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu) * for TSS T flag #DBs). KVM also doesn't save/restore pending MTF * across SMI/RSM as it should; that needs to be addressed in order to * prioritize SMI over MTF and trap-like #DBs. - * - * Note that only a pending nested run can block a pending exception. - * Otherwise an injected NMI/interrupt should either be - * lost or delivered to the nested hypervisor in the IDT_VECTORING_INFO, - * while delivering the pending exception. */ if (vcpu->arch.exception.pending && !(vmx_get_pending_dbg_trap(vcpu) & ~DR6_BT)) { - if (vmx->nested.nested_run_pending) + if (block_nested_exceptions) return -EBUSY; if (!nested_vmx_check_exception(vcpu, &exit_qual)) goto no_vmexit; @@ -4013,7 +4020,7 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu) } if (vcpu->arch.exception.pending) { - if (vmx->nested.nested_run_pending) + if (block_nested_exceptions) return -EBUSY; if (!nested_vmx_check_exception(vcpu, &exit_qual)) goto no_vmexit; |