From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Cc: 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: Tue, 13 Apr 2021 14:10:02 +0200 [thread overview]
Message-ID: <4a9e11b1-9cd6-b9a4-d9ea-f2f4d0983084@redhat.com> (raw)
In-Reply-To: <YHS/BxMiO6I1VOEY@google.com>
On 12/04/21 23:43, Sean Christopherson wrote:
> where kvm_arch_interrupt_allowed() checks EFLAGS.IF (and an edge case related to
> nested virtualization). KVM also captures EFLAGS.IF in vcpu->run->if_flag.
> For whatever reason, QEMU checks both vcpu->run flags before injecting an IRQ,
> maybe to handle a case where QEMU itself clears EFLAGS.IF?
It's mostly obsolete code (that will be deprecated in the next version
and removed in about a year) so I wouldn't read much into it. if_flag
itself is obsolete; it is not provided by SEV-ES, and a useless subset
of ready_for_interrupt_injection.
Paolo
next prev parent reply other threads:[~2021-04-13 12:10 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
2021-04-15 8:06 ` Lai Jiangshan
2021-04-13 12:10 ` Paolo Bonzini [this message]
2020-11-27 12:49 ` [PATCH 0/2] KVM: x86: cleanup and fix userspace interrupt window David Woodhouse
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