From: Paolo Bonzini pbonzini@redhat.com
commit de7cd3f6761f49bef044ec49493d88737a70f1a6 upstream.
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 Reviewed-by: Sean Christopherson seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/x86.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9642,14 +9642,14 @@ static int vcpu_enter_guest(struct kvm_v 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