diff options
| author | Sean Christopherson <seanjc@google.com> | 2024-11-01 12:14:43 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-12-19 07:34:11 -0800 |
| commit | cda3960fbcc532f8609fc32b07196abe2a2f0376 (patch) | |
| tree | 97b18c428308cbd2cd39197d3bd4c2425f9288dc | |
| parent | fdd2db5126ce9cce22947354008d430252b08a03 (diff) | |
KVM: nVMX: Explicitly update vPPR on successful nested VM-Enter
Always request pending event evaluation after successful nested VM-Enter
if L1 has a pending IRQ, as KVM will effectively do so anyways when APICv
is enabled, by way of vmx_has_apicv_interrupt(). This will allow dropping
the aforementioned APICv check, and will also allow handling nested Posted
Interrupt processing entirely within vmx_check_nested_events(), which is
necessary to honor priority between concurrent events.
Note, checking for pending IRQs has a subtle side effect, as it results in
a PPR update for L1's vAPIC (PPR virtualization does happen at VM-Enter,
but for nested VM-Enter that affects L2's vAPIC, not L1's vAPIC). However,
KVM updates PPR _constantly_, even when PPR technically shouldn't be
refreshed, e.g. kvm_vcpu_has_events() re-evaluates PPR if IRQs are
unblocked, by way of the same kvm_apic_has_interrupt() check. Ditto for
nested VM-Enter itself, when nested posted interrupts are enabled. Thus,
trying to avoid a PPR update on VM-Enter just to be pedantically accurate
is ridiculous, given the behavior elsewhere in KVM.
Link: https://lore.kernel.org/kvm/20230312180048.1778187-1-jason.cj.chen@intel.com
Closes: https://lore.kernel.org/all/20240920080012.74405-1-mankku@gmail.com
Signed-off-by: Chao Gao <chao.gao@intel.com>
Link: https://lore.kernel.org/r/20241101191447.1807602-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 103baa8e4cf8..a8f8ac0f26d2 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3618,7 +3618,8 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, * effectively unblock various events, e.g. INIT/SIPI cause VM-Exit * unconditionally. */ - if (unlikely(evaluate_pending_interrupts)) + if (unlikely(evaluate_pending_interrupts) || + kvm_apic_has_interrupt(vcpu)) kvm_make_request(KVM_REQ_EVENT, vcpu); /* |