On 01/03/2018 15:24, Radim Krčmář wrote:
> Moving the code around broke this rare configuration.
> Use this opportunity to finally call lapic reset from vcpu reset.
>
> Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Fixes: 0b2e9904c159 ("KVM: x86: move LAPIC initialization after VMCS creation")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> ---
> arch/x86/kvm/lapic.c | 10 ++++------
> arch/x86/kvm/x86.c | 3 ++-
> 2 files changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index cc5fe7a50dde..391dda8d43b7 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -2002,14 +2002,13 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
>
> void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
> {
> - struct kvm_lapic *apic;
> + struct kvm_lapic *apic = vcpu->arch.apic;
> int i;
>
> - apic_debug("%s\n", __func__);
> + if (!apic)
> + return;
>
> - ASSERT(vcpu);
> - apic = vcpu->arch.apic;
> - ASSERT(apic != NULL);
> + apic_debug("%s\n", __func__);
>
> /* Stop the timer in case it's a reset to an active apic */
> hrtimer_cancel(&apic->lapic_timer.timer);
> @@ -2568,7 +2567,6 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
>
> pe = xchg(&apic->pending_events, 0);
> if (test_bit(KVM_APIC_INIT, &pe)) {
> - kvm_lapic_reset(vcpu, true);
> kvm_vcpu_reset(vcpu, true);
> if (kvm_vcpu_is_bsp(apic->vcpu))
> vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 1a3ed81031f1..3f96b51d0495 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -8123,7 +8123,6 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
> kvm_vcpu_mtrr_init(vcpu);
> vcpu_load(vcpu);
> kvm_vcpu_reset(vcpu, false);
> - kvm_lapic_reset(vcpu, false);
> kvm_mmu_setup(vcpu);
> vcpu_put(vcpu);
> return 0;
> @@ -8166,6 +8165,8 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
>
> void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
> {
> + kvm_lapic_reset(vcpu, init_event);
> +
> vcpu->arch.hflags = 0;
>
> vcpu->arch.smi_pending = 0;
>
Much better indeed, thanks.
Paolo