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KVM: x86: Formalize blocking of nested pending exceptions

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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>
This commit is contained in:
Sean Christopherson 2022-08-30 23:16:02 +00:00 committed by Paolo Bonzini
parent d4963e319f
commit 72c14e00bd
2 changed files with 33 additions and 20 deletions
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26
arch/x86/kvm/svm/nested.c
View File

@ -1360,10 +1360,22 @@ static inline bool nested_exit_on_init(struct vcpu_svm *svm)
static int svm_check_nested_events(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
bool block_nested_events =
kvm_event_needs_reinjection(vcpu) || svm->nested.nested_run_pending;
struct kvm_lapic *apic = vcpu->arch.apic;
struct vcpu_svm *svm = to_svm(vcpu);
/*
* 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 = svm->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)) {
@ -1376,13 +1388,7 @@ static int svm_check_nested_events(struct kvm_vcpu *vcpu)
}
if (vcpu->arch.exception.pending) {
/*
* 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 EXITINTINFO
* vmcb field, while delivering the pending exception.
*/
if (svm->nested.nested_run_pending)
if (block_nested_exceptions)
return -EBUSY;
if (!nested_exit_on_exception(svm))
return 0;

27
arch/x86/kvm/vmx/nested.c
View File

@ -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;