Check for pending (and notified!) posted interrupts when checking if L2
has a pending wake event, as fully posted/notified virtual interrupt is a
valid wake event for HLT.
Note that KVM must check vmx->nested.pi_pending to avoid prematurely
waking L2, e.g. even if KVM sees a non-zero PID.PIR and PID.0N=1, the
virtual interrupt won't actually be recognized until a notification IRQ is
received by the vCPU or the vCPU does (nested) VM-Enter.
Fixes: 26844fee6ade ("KVM: x86: never write to memory from kvm_vcpu_check_block()")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Reported-by: Jim Mattson <jmattson@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/20231207010302.2240506-1-jmattson@xxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 36 ++++++++++++++++++++++++++++++++++--
1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 9099c1d0c7cb..3bac65591f20 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4034,8 +4034,40 @@ static bool nested_vmx_preemption_timer_pending(struct kvm_vcpu *vcpu)
static bool vmx_has_nested_events(struct kvm_vcpu *vcpu, bool for_injection)
{
- return nested_vmx_preemption_timer_pending(vcpu) ||
- to_vmx(vcpu)->nested.mtf_pending;
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ void *vapic = vmx->nested.virtual_apic_map.hva;
+ int max_irr, vppr;
+
+ if (nested_vmx_preemption_timer_pending(vcpu) ||
+ vmx->nested.mtf_pending)
+ return true;
+
+ /*
+ * Virtual Interrupt Delivery doesn't require manual injection. Either
+ * the interrupt is already in GUEST_RVI and will be recognized by CPU
+ * at VM-Entry, or there is a KVM_REQ_EVENT pending and KVM will move
+ * the interrupt from the PIR to RVI prior to entering the guest.
+ */
+ if (for_injection)
+ return false;
+
+ if (!nested_cpu_has_vid(get_vmcs12(vcpu)) ||
+ __vmx_interrupt_blocked(vcpu))
+ return false;
+
+ if (!vapic)
+ return false;
+
+ vppr = *((u32 *)(vapic + APIC_PROCPRI));
+
+ if (vmx->nested.pi_pending && vmx->nested.pi_desc &&
+ pi_test_on(vmx->nested.pi_desc)) {
+ max_irr = pi_find_highest_vector(vmx->nested.pi_desc);
+ if (max_irr > 0 && (max_irr & 0xf0) > (vppr & 0xf0))
+ return true;
+ }
+
+ return false;
}
/*
--
2.45.2.505.gda0bf45e8d-goog
