Messages in this thread Patch in this message | | | From | Paolo Bonzini <> | Subject | [PATCH] KVM: x86: check for interrupts before deciding whether to exit the fast path | Date | Wed, 20 Oct 2021 10:52:29 -0400 |
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The kvm_x86_sync_pir_to_irr callback can sometimes set KVM_REQ_EVENT. If that happens exactly at the time that an exit is handled as EXIT_FASTPATH_REENTER_GUEST, vcpu_enter_guest will go incorrectly through the loop that calls kvm_x86_run, instead of processing the request promptly.
Fixes: 379a3c8ee444 ("KVM: VMX: Optimize posted-interrupt delivery for timer fastpath") Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/x86.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fa48948b4934..b9b31e5f72b0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9781,14 +9781,14 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST)) break; - if (unlikely(kvm_vcpu_exit_request(vcpu))) { + if (vcpu->arch.apicv_active) + static_call(kvm_x86_sync_pir_to_irr)(vcpu); + + if (unlikely(kvm_vcpu_exit_request(vcpu))) { exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED; break; } - - if (vcpu->arch.apicv_active) - static_call(kvm_x86_sync_pir_to_irr)(vcpu); - } + } /* * Do this here before restoring debug registers on the host. And -- 2.27.0
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