From c112b5f50232a257056903040c66d97efb536889 Mon Sep 17 00:00:00 2001 From: Luwei Kang Date: Thu, 14 Feb 2019 10:48:07 +0800 Subject: KVM: x86: Recompute PID.ON when clearing PID.SN 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 comes at this time, the irq remapping facility will set the bit of PIR (Posted Interrupt Requests) but not ON (Outstanding Notification). Then, the interrupt will not be seen by KVM, which always expects PID.ON=1 if PID.PIR=1 as documented in the Intel processor SDM but not in the VT-d specification. To fix this, restore the invariant after PID.SN is cleared. Signed-off-by: Luwei Kang Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/vmx.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch/x86/kvm/vmx/vmx.h') diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 99328954c2fc..0ac0a64c7790 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -337,16 +337,16 @@ static inline int pi_test_and_set_pir(int vector, struct pi_desc *pi_desc) return test_and_set_bit(vector, (unsigned long *)pi_desc->pir); } -static inline void pi_clear_sn(struct pi_desc *pi_desc) +static inline void pi_set_sn(struct pi_desc *pi_desc) { - return clear_bit(POSTED_INTR_SN, + return set_bit(POSTED_INTR_SN, (unsigned long *)&pi_desc->control); } -static inline void pi_set_sn(struct pi_desc *pi_desc) +static inline void pi_set_on(struct pi_desc *pi_desc) { - return set_bit(POSTED_INTR_SN, - (unsigned long *)&pi_desc->control); + set_bit(POSTED_INTR_ON, + (unsigned long *)&pi_desc->control); } static inline void pi_clear_on(struct pi_desc *pi_desc) -- cgit v1.2.3