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Commit f563db4b authored by Radim Krčmář's avatar Radim Krčmář Committed by Marcelo Tosatti
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KVM: SVM: fix interrupt injection (apic->isr_count always 0) 



In commit b4eef9b3, we started to use hwapic_isr_update() != NULL
instead of kvm_apic_vid_enabled(vcpu->kvm).  This didn't work because
SVM had it defined and "apicv" path in apic_{set,clear}_isr() does not
change apic->isr_count, because it should always be 1.  The initial
value of apic->isr_count was based on kvm_apic_vid_enabled(vcpu->kvm),
which is always 0 for SVM, so KVM could have injected interrupts when it
shouldn't.

Fix it by implicitly setting SVM's hwapic_isr_update to NULL and make the
initial isr_count depend on hwapic_isr_update() for good measure.

Fixes: b4eef9b3 ("kvm: x86: vmx: NULL out hwapic_isr_update() in case of !enable_apicv")
Reported-and-tested-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 4ff6f8e6

arch/x86/kvm/lapic.c

+2 −2
Original line number Diff line number Diff line
@@ -1572,7 +1572,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu) 
		apic_set_reg(apic, APIC_TMR + 0x10 * i, 0);

	}

	apic->irr_pending = kvm_apic_vid_enabled(vcpu->kvm);

	apic->isr_count = kvm_apic_vid_enabled(vcpu->kvm);

	apic->isr_count = kvm_x86_ops->hwapic_isr_update ? 1 : 0;

	apic->highest_isr_cache = -1;

	update_divide_count(apic);

	atomic_set(&apic->lapic_timer.pending, 0);
@@ -1782,7 +1782,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu, 
	update_divide_count(apic);

	start_apic_timer(apic);

	apic->irr_pending = true;

	apic->isr_count = kvm_apic_vid_enabled(vcpu->kvm) ?

	apic->isr_count = kvm_x86_ops->hwapic_isr_update ?

				1 : count_vectors(apic->regs + APIC_ISR);

	apic->highest_isr_cache = -1;

	if (kvm_x86_ops->hwapic_irr_update)

arch/x86/kvm/svm.c

+0 −6
Original line number Diff line number Diff line
@@ -3649,11 +3649,6 @@ static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap) 
	return;

}



static void svm_hwapic_isr_update(struct kvm *kvm, int isr)

{

	return;

}



static void svm_sync_pir_to_irr(struct kvm_vcpu *vcpu)

{

	return;
@@ -4403,7 +4398,6 @@ static struct kvm_x86_ops svm_x86_ops = { 
	.set_virtual_x2apic_mode = svm_set_virtual_x2apic_mode,

	.vm_has_apicv = svm_vm_has_apicv,

	.load_eoi_exitmap = svm_load_eoi_exitmap,

	.hwapic_isr_update = svm_hwapic_isr_update,

	.sync_pir_to_irr = svm_sync_pir_to_irr,



	.set_tss_addr = svm_set_tss_addr,