From: Sean Christopherson <seanjc@google.com>
To: Adamos Ttofari <attofari@amazon.de>
Cc: dwmw@amazon.co.uk, "Paolo Bonzini" <pbonzini@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Nikita Leshenko" <nikita.leshchenko@oracle.com>,
"Liran Alon" <liran.alon@oracle.com>,
"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] KVM: x86: ioapic: Fix level-triggered EOI and userspace I/OAPIC reconfigure race
Date: Fri, 9 Dec 2022 01:34:23 +0000 [thread overview]
Message-ID: <Y5KQnyZYkfGkBIvR@google.com> (raw)
In-Reply-To: <20221208094415.12723-1-attofari@amazon.de>
On Thu, Dec 08, 2022, Adamos Ttofari wrote:
> When scanning userspace I/OAPIC entries, intercept EOI for level-triggered
> IRQs if the current vCPU has a pending and/or in-service IRQ for the
> vector in its local API, even if the vCPU doesn't match the new entry's
> destination. This fixes a race between userspace I/OAPIC reconfiguration
> and IRQ delivery that results in the vector's bit being left set in the
> remote IRR due to the eventual EOI not being forwarded to the userspace
> I/OAPIC.
>
> Commit 0fc5a36dd6b3 ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC
> reconfigure race") fixed the in-kernel IOAPIC, but not the userspace
> IOAPIC configuration, which has a similar race.
>
> Fixes: 0fc5a36dd6b3 ("KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race")
>
> Signed-off-by: Adamos Ttofari <attofari@amazon.de>
> ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
prev parent reply other threads:[~2022-12-09 1:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-07 9:13 [PATCH] KVM: x86: ioapic: Fix level-triggered EOI and userspace IOAPIC reconfigure race Adamos Ttofari
2022-12-07 9:42 ` David Woodhouse
2022-12-07 16:13 ` Sean Christopherson
2022-12-08 9:44 ` [PATCH v2] KVM: x86: ioapic: Fix level-triggered EOI and userspace I/OAPIC " Adamos Ttofari
2022-12-09 1:34 ` Sean Christopherson [this message]
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