* [PATCH v2] KVM: X86: Fix loss of pending INIT due to race
@ 2017-08-01 23:05 Wanpeng Li
2017-08-02 7:44 ` Paolo Bonzini
0 siblings, 1 reply; 2+ messages in thread
From: Wanpeng Li @ 2017-08-01 23:05 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
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 <peng.hao2@zte.com.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
v1 -> v2:
* move the stuff under if (events->smi_smm)
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 1a4c84d..839b5dad6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3160,15 +3160,18 @@ 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);
+ }
}
}
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] KVM: X86: Fix loss of pending INIT due to race
2017-08-01 23:05 [PATCH v2] KVM: X86: Fix loss of pending INIT due to race Wanpeng Li
@ 2017-08-02 7:44 ` Paolo Bonzini
0 siblings, 0 replies; 2+ messages in thread
From: Paolo Bonzini @ 2017-08-02 7:44 UTC (permalink / raw)
To: Wanpeng Li, linux-kernel, kvm; +Cc: Radim Krčmář, Wanpeng Li
On 02/08/2017 01:05, Wanpeng Li wrote:
> From: Wanpeng Li <wanpeng.li@hotmail.com>
>
> 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 <peng.hao2@zte.com.cn>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
> v1 -> v2:
> * move the stuff under if (events->smi_smm)
>
> 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 1a4c84d..839b5dad6 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3160,15 +3160,18 @@ 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);
> + }
> }
> }
>
>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-08-02 7:44 ` Paolo Bonzini
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