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Wed, 26 Aug 2026 21:48:23 -0700 (PDT) From: Hemanth Selam To: seanjc@google.com, pbonzini@redhat.com, shuah@kernel.org Cc: sashiko-reviews@lists.linux.dev, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] KVM: selftests: Add a helper to read a vCPU's APIC ID Date: Thu, 27 Aug 2026 10:18:00 +0530 Message-ID: <20260827044800.2917294-1-hemanth.selam@gmail.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20260826115915.2882221-1-hemanth.selam@gmail.com> References: <20260826115915.2882221-1-hemanth.selam@gmail.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Please skip this version, the report is right: the helper applied the xAPIC shift and mask unconditionally, so it returned 0 for a vCPU in x2APIC mode on a VM that enabled KVM_X2APIC_API_USE_32BIT_IDS, and truncated IDs above 255. v3 handles both modes and I checked it against every way KVM reports an ID, including a vCPU with ID 300 and a guest that renames its own xAPIC ID: https://lore.kernel.org/all/20260827044534.2900285-1-hemanth.selam@gmail.com Hemanth