From: Paolo Bonzini <pbonzini@redhat.com>
To: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Cc: Sean Christopherson <seanjc@google.com>,
LKML <linux-kernel@vger.kernel.org>,
kvm@vger.kernel.org, Filippo Sironi <sironi@amazon.de>,
David Woodhouse <dwmw@amazon.co.uk>,
"v4.7+" <stable@vger.kernel.org>,
Wanpeng Li <wanpengli@tencent.com>
Subject: Re: [PATCH 2/2] KVM: x86: Fix split-irqchip vs interrupt injection window request
Date: Thu, 15 Apr 2021 08:07:06 +0200 [thread overview]
Message-ID: <5b422691-ffc5-d73a-1bda-f1ee61116756@redhat.com> (raw)
In-Reply-To: <CAJhGHyA=v_va2QTvo7Ve8JyZO4j5LjiCdB9CLnvRXGwGwa3e+A@mail.gmail.com>
On 15/04/21 02:59, Lai Jiangshan wrote:
> The next call to inject_pending_event() will reach here AT FIRST with
> vcpu->arch.exception.injected==false and vcpu->arch.exception.pending==false
>
>> ... if (!vcpu->arch.exception.pending) {
>> if (vcpu->arch.nmi_injected) {
>> static_call(kvm_x86_set_nmi)(vcpu);
>> can_inject = false;
>> } else if (vcpu->arch.interrupt.injected) {
>> static_call(kvm_x86_set_irq)(vcpu);
>> can_inject = false;
>
> And comes here and vcpu->arch.interrupt.injected is true for there is
> an interrupt queued by KVM_INTERRUPT for pure user irqchip. It then does
> the injection of the interrupt without checking the EFLAGS.IF.
Ok, understood now. Yeah, that could be a problem for userspace irqchip
so we should switch it to use pending_external_vector instead. Are you
going to write the patch or should I?
Thanks!
Paolo
> My question is that what stops the next call to inject_pending_event()
> to reach here when KVM_INTERRUPT is called with exepction pending.
next prev parent reply other threads:[~2021-04-15 6:07 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-27 11:21 [PATCH 0/2] KVM: x86: cleanup and fix userspace interrupt window Paolo Bonzini
2020-11-27 11:21 ` [PATCH 1/2] KVM: x86: handle !lapic_in_kernel case in kvm_cpu_*_extint Paolo Bonzini
2020-11-27 11:56 ` David Woodhouse
2020-11-27 12:52 ` Filippo Sironi
2020-11-27 11:21 ` [PATCH 2/2] KVM: x86: Fix split-irqchip vs interrupt injection window request Paolo Bonzini
2020-11-27 12:53 ` Filippo Sironi
2021-04-09 7:14 ` Lai Jiangshan
2021-04-12 21:43 ` Sean Christopherson
2021-04-13 11:03 ` Lai Jiangshan
2021-04-13 12:15 ` Paolo Bonzini
2021-04-14 2:28 ` Lai Jiangshan
2021-04-14 16:58 ` Paolo Bonzini
2021-04-15 0:59 ` Lai Jiangshan
2021-04-15 6:07 ` Paolo Bonzini [this message]
2021-04-15 8:06 ` Lai Jiangshan
2021-04-13 12:10 ` Paolo Bonzini
2020-11-27 12:49 ` [PATCH 0/2] KVM: x86: cleanup and fix userspace interrupt window David Woodhouse
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