Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
Date:   Tue, 17 Oct 2023 18:16:20 -0700
In-Reply-To: <20231017155101.40677-1-nsaenz@amazon.com>
Mime-Version: 1.0
References: <20231017155101.40677-1-nsaenz@amazon.com>
Message-ID: <169759163972.1787364.3932584247097617727.b4-ty@google.com>
Subject: Re: [PATCH v3] KVM: x86: hyper-v: Don't auto-enable stimer on write
 from user-space
From:   Sean Christopherson <seanjc@google.com>
To:     Sean Christopherson <seanjc@google.com>, kvm@vger.kernel.org,
        Nicolas Saenz Julienne <nsaenz@amazon.com>
Cc:     vkuznets@redhat.com, pbonzini@redhat.com, tglx@linutronix.de,
        mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, graf@amazon.de, rkagan@amazon.de,
        linux-kernel@vger.kernel.org, anelkz@amazon.de,
        stable@vger.kernel.org
Content-Type: text/plain; charset="utf-8"
Precedence: bulk

On Tue, 17 Oct 2023 15:51:02 +0000, Nicolas Saenz Julienne wrote:
> Don't apply the stimer's counter side effects when modifying its
> value from user-space, as this may trigger spurious interrupts.
> 
> For example:
>  - The stimer is configured in auto-enable mode.
>  - The stimer's count is set and the timer enabled.
>  - The stimer expires, an interrupt is injected.
>  - The VM is live migrated.
>  - The stimer config and count are deserialized, auto-enable is ON, the
>    stimer is re-enabled.
>  - The stimer expires right away, and injects an unwarranted interrupt.
> 
> [...]

Applied to kvm-x86 misc, thanks!

[1/1] KVM: x86: hyper-v: Don't auto-enable stimer on write from user-space
      https://github.com/kvm-x86/linux/commit/d6800af51c76

--
https://github.com/kvm-x86/linux/tree/next