From 81b016676e1c8f58027bd4d2b1d8a981776b36fe Mon Sep 17 00:00:00 2001 From: Luwei Kang Date: Thu, 31 Jan 2019 16:52:02 +0800 Subject: KVM: x86: Sync the pending Posted-Interrupts Some Posted-Interrupts from passthrough devices may be lost or overwritten when the vCPU is in runnable state. The SN (Suppress Notification) of PID (Posted Interrupt Descriptor) will be set when the vCPU is preempted (vCPU in KVM_MP_STATE_RUNNABLE state but not running on physical CPU). If a posted interrupt coming at this time, the irq remmaping facility will set the bit of PIR (Posted Interrupt Requests) without ON (Outstanding Notification). So this interrupt can't be sync to APIC virtualization register and will not be handled by Guest because ON is zero. Signed-off-by: Luwei Kang [Eliminate the pi_clear_sn fast path. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a1fb99f21317..96f87d356c79 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7808,7 +7808,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) * 1) We should set ->mode before checking ->requests. Please see * the comment in kvm_vcpu_exiting_guest_mode(). * - * 2) For APICv, we should set ->mode before checking PIR.ON. This + * 2) For APICv, we should set ->mode before checking PID.ON. This * pairs with the memory barrier implicit in pi_test_and_set_on * (see vmx_deliver_posted_interrupt). * -- cgit