Re: [Qemu-devel] [RFC/PATCH 2] kvm: x86: handle KVM_SET_VCPU_EVENTS/KVM_VCPUEVENT_VALID_SMM properly

[Paolo Bonzini <pbonzini@redhat.com>]

On 22/09/2016 09:51, Herongguang (Stephen) wrote:
> After making memory consistent between source and destination
> (https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg03069.html),
> there can
> still reproduce instruction emulation failure in destination side if
> migration when VM’s in grub stage:

Hi!  Did you follow up on that patch, by the way?

> So I think there is some lacking in kvm-kmod’s
> kvm_vcpu_ioctl_x86_set_vcpu_events that handles KVM_VCPUEVENT_VALID_SMM.
> I tried following patch,
> it seems works fine.
> 
> Do you think this patch is appropriate or not enough? Thanks.

Yes.  I would just call kvm_mmu_reset_context unconditionally at the end
of kvm_vcpu_iocyl_x86_set_x86_vcpu_events.  Please send this patch as
non-RFC.

Patch 3 is also okay, please send it separately.

Thanks,

Paolo

> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 19f9f9e..f39e839 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -3013,8 +3013,10 @@ static int
> kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
>                 vcpu->arch.apic->sipi_vector = events->sipi_vector;
> 
>         if (events->flags & KVM_VCPUEVENT_VALID_SMM) {
> -               if (events->smi.smm)
> +               if (events->smi.smm) {
>                         vcpu->arch.hflags |= HF_SMM_MASK;
> +                       kvm_mmu_reset_context(vcpu);
> +               }
>                 else
>                         vcpu->arch.hflags &= ~HF_SMM_MASK;
>                 vcpu->arch.smi_pending = events->smi.pending;
> 
>