Commit b4830f3a authored by Radim Krčmář's avatar Radim Krčmář Committed by Greg Kroah-Hartman
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KVM: x86: fix vcpu initialization with userspace lapic 



commit b7e31be3 upstream.

Moving the code around broke this rare configuration.
Use this opportunity to finally call lapic reset from vcpu reset.

Reported-by: default avatar <syzbot+fb7a33a4b6c35007a72b@syzkaller.appspotmail.com>
Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Fixes: 0b2e9904 ("KVM: x86: move LAPIC initialization after VMCS creation")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1f17daea

arch/x86/kvm/lapic.c

+4 −6
Original line number Original line Diff line number Diff line
@@ -1944,14 +1944,13 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) 




void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)

void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)

{

{

	struct kvm_lapic *apic;

	struct kvm_lapic *apic = vcpu->arch.apic;

	int i;

	int i;





	apic_debug("%s\n", __func__);

	if (!apic)

		return;





	ASSERT(vcpu);

	apic_debug("%s\n", __func__);

	apic = vcpu->arch.apic;

	ASSERT(apic != NULL);





	/* Stop the timer in case it's a reset to an active apic */

	/* Stop the timer in case it's a reset to an active apic */

	hrtimer_cancel(&apic->lapic_timer.timer);

	hrtimer_cancel(&apic->lapic_timer.timer);
@@ -2510,7 +2509,6 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu) 




	pe = xchg(&apic->pending_events, 0);

	pe = xchg(&apic->pending_events, 0);

	if (test_bit(KVM_APIC_INIT, &pe)) {

	if (test_bit(KVM_APIC_INIT, &pe)) {

		kvm_lapic_reset(vcpu, true);

		kvm_vcpu_reset(vcpu, true);

		kvm_vcpu_reset(vcpu, true);

		if (kvm_vcpu_is_bsp(apic->vcpu))

		if (kvm_vcpu_is_bsp(apic->vcpu))

			vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;

			vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;

arch/x86/kvm/x86.c

+2 −1
Original line number Original line Diff line number Diff line
@@ -7779,7 +7779,6 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) 
	if (r)

	if (r)

		return r;

		return r;

	kvm_vcpu_reset(vcpu, false);

	kvm_vcpu_reset(vcpu, false);

	kvm_lapic_reset(vcpu, false);

	kvm_mmu_setup(vcpu);

	kvm_mmu_setup(vcpu);

	vcpu_put(vcpu);

	vcpu_put(vcpu);

	return r;

	return r;
@@ -7822,6 +7821,8 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) 




void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)

void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)

{

{

	kvm_lapic_reset(vcpu, init_event);



	vcpu->arch.hflags = 0;

	vcpu->arch.hflags = 0;





	vcpu->arch.smi_pending = 0;

	vcpu->arch.smi_pending = 0;