On Thu, Mar 1, 2018 at 3:24 PM, Radim Krčmář <rkrcmar@xxxxxxxxxx> 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> This was reported by syzbot: https://groups.google.com/d/msg/syzkaller-bugs/QrDXoM_mQRk/mT2cebykBQAJ Please add the Reported-by: syzbot+fb7a33a4b6c35007a72b@xxxxxxxxxxxxxxxxxxxxxxxxx tag so that syzbot will know when it's fixed. > 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; > -- > 2.15.1 >
