From f57ad63a835c6f1fe646ea985e78a79eb206a5b3 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Thu, 3 Dec 2020 16:33:19 +0200
Subject: [PATCH] KVM: x86: ignore SIPIs that are received while not in
wait-for-sipi state
In the commit 1c96dcceaeb3
("KVM: x86: fix apic_accept_events vs check_nested_events"),
we accidently started latching SIPIs that are received while the cpu is not
waiting for them.
This causes vCPUs to never enter a halted state.
Fixes: 1c96dcceaeb3 ("KVM: x86: fix apic_accept_events vs check_nested_events")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20201203143319.159394-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index e3ee597ff5404..6a87623aa578e 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2892,14 +2892,15 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
else
vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
}
- if (test_bit(KVM_APIC_SIPI, &pe) &&
- vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
+ if (test_bit(KVM_APIC_SIPI, &pe)) {
clear_bit(KVM_APIC_SIPI, &apic->pending_events);
- /* evaluate pending_events before reading the vector */
- smp_rmb();
- sipi_vector = apic->sipi_vector;
- kvm_vcpu_deliver_sipi_vector(vcpu, sipi_vector);
- vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+ if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
+ /* evaluate pending_events before reading the vector */
+ smp_rmb();
+ sipi_vector = apic->sipi_vector;
+ kvm_vcpu_deliver_sipi_vector(vcpu, sipi_vector);
+ vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+ }
}
}