From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH 1/3] KVM: APIC: remove unnecessary double checks on APIC existence
Date: Tue, 9 Feb 2016 14:55:03 +0100 [thread overview]
Message-ID: <20160209135502.GA30378@potion.brq.redhat.com> (raw)
In-Reply-To: <1454948146-35353-2-git-send-email-pbonzini@redhat.com>
2016-02-08 17:15+0100, Paolo Bonzini:
> Usually the in-kernel APIC's existence is checked in the caller. Do not
> bother checking it again in lapic.c.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> @@ -1601,8 +1595,7 @@ static int apic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this,
>
> void kvm_lapic_set_eoi(struct kvm_vcpu *vcpu)
> {
> - if (kvm_vcpu_has_lapic(vcpu))
> - apic_reg_write(vcpu->arch.apic, APIC_EOI, 0);
> + apic_reg_write(vcpu->arch.apic, APIC_EOI, 0);
This is most likely going to bug on the following path:
handle_apic_access -> kvm_lapic_set_eoi
Before the change, handle_apic_access would just drop EOIs that should
have gone to user space ... I'm not sure if we tested it, or the path is
really never taken.
next prev parent reply other threads:[~2016-02-09 13:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-08 16:15 [PATCH 0/3] KVM: x86: consolidate "has lapic" checks Paolo Bonzini
2016-02-08 16:15 ` [PATCH 1/3] KVM: APIC: remove unnecessary double checks on APIC existence Paolo Bonzini
2016-02-09 13:55 ` Radim Krčmář [this message]
2016-02-09 15:06 ` Paolo Bonzini
2016-02-09 15:18 ` Radim Krčmář
2016-02-08 16:15 ` [PATCH 2/3] KVM: x86: consolidate "has lapic" checks into irq.c Paolo Bonzini
2016-02-09 14:05 ` Radim Krčmář
2016-02-09 15:07 ` Paolo Bonzini
2016-02-09 15:21 ` Radim Krčmář
2016-02-08 16:15 ` [PATCH 3/3] KVM: x86: consolidate different ways to test for in-kernel LAPIC Paolo Bonzini
2016-02-09 14:14 ` Radim Krčmář
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