From f4ef19108608c81769db69976999d056c070a6f0 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 1 Aug 2017 16:05:25 -0700 Subject: [PATCH] KVM: X86: Fix loss of pending INIT due to race MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When SMP VM start, AP may lost INIT because of receiving INIT between kvm_vcpu_ioctl_x86_get/set_vcpu_events. vcpu 0 vcpu 1 kvm_vcpu_ioctl_x86_get_vcpu_events events->smi.latched_init = 0 send INIT to vcpu1 set vcpu1's pending_events kvm_vcpu_ioctl_x86_set_vcpu_events if (events->smi.latched_init == 0) clear INIT in pending_events This patch fixes it by just update SMM related flags if we are in SMM. Thanks Peng Hao for the report and original commit message. Reported-by: Peng Hao Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li Reviewed-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/kvm/x86.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6c97c82814c4..037055a31b13 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3159,15 +3159,18 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, kvm_set_hflags(vcpu, hflags); vcpu->arch.smi_pending = events->smi.pending; - if (events->smi.smm_inside_nmi) - vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK; - else - vcpu->arch.hflags &= ~HF_SMM_INSIDE_NMI_MASK; - if (lapic_in_kernel(vcpu)) { - if (events->smi.latched_init) - set_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events); + + if (events->smi.smm) { + if (events->smi.smm_inside_nmi) + vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK; else - clear_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events); + vcpu->arch.hflags &= ~HF_SMM_INSIDE_NMI_MASK; + if (lapic_in_kernel(vcpu)) { + if (events->smi.latched_init) + set_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events); + else + clear_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events); + } } } -- 2.30.2