| Message ID | 20191111172012.28356-2-joao.m.martins@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: VMX: Posted Interrupts fixes | expand |
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 31ce6bc2c371..4c7d2935f7ec 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6141,7 +6141,11 @@ static int vmx_sync_pir_to_irr(struct kvm_vcpu *vcpu) static bool vmx_dy_apicv_has_pending_interrupt(struct kvm_vcpu *vcpu) { - return pi_test_on(vcpu_to_pi_desc(vcpu)); + struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); + + return pi_test_on(pi_desc) || + (pi_test_sn(pi_desc) && + !bitmap_empty((unsigned long *)pi_desc->pir, NR_VECTORS)); } static void vmx_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap)
Commit 17e433b54393 ("KVM: Fix leak vCPU's VMCS value into other pCPU") introduced vmx_dy_apicv_has_pending_interrupt() in order to determine if a vCPU have a pending posted interrupt. This routine is used by kvm_vcpu_on_spin() when searching for a a new runnable vCPU to schedule on pCPU instead of a vCPU doing busy loop. vmx_dy_apicv_has_pending_interrupt() determines if a vCPU has a pending posted interrupt solely based on PID.ON. However, when a vCPU is preempted, vmx_vcpu_pi_put() sets PID.SN which cause raised posted interrupts to only set bit in PID.PIR without setting PID.ON (and without sending notification vector), as depicted in VT-d manual section 5.2.3 "Interrupt-Posting Hardware Operation". Therefore, checking PID.ON is insufficient to determine if a vCPU has pending posted interrupts and instead we should also check if there is some bit set on PID.PIR if PID.SN=1. Fixes: 17e433b54393 ("KVM: Fix leak vCPU's VMCS value into other pCPU") Reviewed-by: Jagannathan Raman <jag.raman@oracle.com> Co-developed-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Liran Alon <liran.alon@oracle.com> Signed-off-by: Joao Martins <joao.m.martins@oracle.com> --- v2: * Fixed broken Sob Chain; * Add missing tags; * Only test PID.PIR if PID.SN=1 and reflect that in commit message last paragraph; --- arch/x86/kvm/vmx/vmx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)