On 10/11/2017 02:24, Liran Alon wrote:
>
> @@ -6720,6 +6720,12 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
> if (!kvm_apic_hw_enabled(vcpu->arch.apic))
> return;
>
> + if (is_guest_mode(vcpu)) {
> + vcpu->arch.scan_ioapic_pending = true;
> + return;
> + }
> + vcpu->arch.scan_ioapic_pending = false;
> +
> bitmap_zero(vcpu->arch.ioapic_handled_vectors, 256);
>
> if (irqchip_split(vcpu->kvm))
I am not sure it is correct to exit immediately. The bug is that you're
losing the EOI exit bitmap in the vmcs01; however, with your patch
you're losing it in the vmcs02. If the L1 hypervisor passes the local
APIC registers to the L2 guest, you would have a similar bug.
However, the patch is generally in the right direction. Another small
issue:
> @@ -6833,7 +6839,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
> goto out;
> }
> }
> - if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu))
> + if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu) ||
> + (!is_guest_mode(vcpu) && vcpu->arch.scan_ioapic_pending))
> vcpu_scan_ioapic(vcpu);
I think this is not reliable because kvm_request_pending(vcpu) might be
false here---and then you never reach the "if" in the first place.
Maybe you can add a
if (vcpu->arch.scan_ioapic_pending)
kvm_make_request(KVM_REQ_SCAN_IOAPIC, vcpu);
to leave_guest_mode in arch/x86/kvm/kvm_cache_regs.h?
Thanks,
Paolo
> if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu))
> kvm_vcpu_reload_apic_access_page(vcpu);
> @@ -7981,6 +7988,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
> kvm = vcpu->kvm;
>
> vcpu->arch.apicv_active = kvm_x86_ops->get_enable_apicv(vcpu);
> + vcpu->arch.scan_ioapic_pending = false;
> vcpu->arch.pv.pv_unhalted = false;
> vcpu->arch.emulate_ctxt.ops = &emulate_ops;
> if (!irqchip_in_kernel(kvm) || kvm_vcpu_is_reset_bsp(vcpu))
>
