On 25/02/2015 20:41, Radim Krčmář wrote:
> 2015-02-25 17:00+0100, Borislav Petkov:
>> Hi,
>>
>> commit in $Subject breaks my kvm guest on AMD host, causing it to do the
>> following below. Mouse doesn't work anymore in the guest, network is
>> gone too.
>>
>> Reverting it fixes the issue.
>
> Thanks,
>
> this patch should fix it.
>
> ---8<---
> In commit b4eef9b36db4, 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 setting SVM's hwapic_isr_update to NULL and make the initial
> isr_count depend on hwapic_isr_update() for good measure.
>
> Fixes: b4eef9b36db4 ("kvm: x86: vmx: NULL out hwapic_isr_update() in case of
> !enable_apicv")
> Reported-by: Borislav Petkov <[email protected]>
> Signed-off-by: Radim Krčmář <[email protected]>
> ---
> arch/x86/kvm/lapic.c | 4 ++--
> arch/x86/kvm/svm.c | 7 +------
> 2 files changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index e55b5fc344eb..bd4e34de24c7 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -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)
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index d319e0c24758..54c7b36ad12d 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -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 +4398,7 @@ 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,
> + .hwapic_isr_update = NULL,
Please remove the line altogether.
Paolo
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