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AHgh+RpeRhuykgrKW/WhAqpQQTkp7dD8M1eXAKRmbsz47M9N+JKx5rUmszLX9o8pjxu+OBuk3bPhpbs=@vger.kernel.org X-Gm-Message-State: AOJu0YzcEG0VQKHrHRHMXrM/X1IUgY4OZqQhnX+alIAY4AwdFVVcxzpJ X4jlG8MQ14sfDQi+IXhGkvh+WjoMBUlTD7pWZ0pk1Af+boCnz+ROGOuqwtbLHud2KHNCQlGuM4i wX9iOtA== X-Received: from pfbcj7.prod.google.com ([2002:a05:6a00:2987:b0:847:8f34:1b76]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:a0f:b0:847:9aa8:d3bb with SMTP id d2e1a72fcca58-847add72a06mr877659b3a.12.1782830528799; Tue, 30 Jun 2026 07:42:08 -0700 (PDT) Date: Tue, 30 Jun 2026 07:42:08 -0700 In-Reply-To: <20260626193343.256956-2-jinpu.wang@ionos.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260626193343.256956-1-jinpu.wang@ionos.com> <20260626193343.256956-2-jinpu.wang@ionos.com> Message-ID: Subject: Re: [stable-6.12 v2 1/3] KVM: SEV: Ignore MMIO requests of length '0' From: Sean Christopherson To: Jack Wang Cc: gregkh@linuxfoundation.org, sashal@kernel.org, stable@vger.kernel.org, Tom Lendacky , Paolo Bonzini Content-Type: text/plain; charset="us-ascii" On Fri, Jun 26, 2026, Jack Wang wrote: > From: Sean Christopherson > > commit 1aa8a6dc7dac8b83234b53518311bf78231f4fa5 upstream. > > Explicitly ignore MMIO requests of length '0', so that setting up the > software scratch area (and other code) doesn't have to worry about > underflowing the length, and to allow for special casing '0' in the > future. > > Fixes: 8f423a80d299 ("KVM: SVM: Support MMIO for an SEV-ES guest") > Cc: stable@vger.kernel.org > Reviewed-by: Tom Lendacky > Signed-off-by: Sean Christopherson > Message-ID: <20260501202250.2115252-3-seanjc@google.com> > Signed-off-by: Paolo Bonzini When sending backports, please document what was changed. Doing so saves maintainer time and is very helpful in case there's a problem with the backport. [Jack: Duplicate the fix to the split READ/WRITE paths] > Signed-off-by: Jack Wang Acked-by: Sean Christopherson