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Wysocki" , Jonathan Corbet , Shuah Khan , Huacai Chen , WANG Xuerui , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Juergen Gross , Boris Ostrovsky , Len Brown , Sunil V L , Mark Rutland , Jonathan Cameron , Kees Cook , Yanteng Si , Sean Christopherson , Kai Huang , Tom Lendacky , Thomas Huth , Thorsten Blum , Kevin Loughlin , Zheyun Shen , Peter Zijlstra , Pawan Gupta , Xin Li , "Ahmed S . Darwish" , Sohil Mehta , Ilkka Koskinen , Robin Murphy , James Clark , Besar Wicaksono , Ma Ke , Ajit Khaparde , Wei Huang , Andy Gospodarek , Somnath Kotur , wangzhou1@hisilicon.com, wanghuiqiang@huawei.com, liuyonglong@huawei.com, linux-pci@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-perf-users@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v5 1/2] ACPI: Rename get_acpi_id_for_cpu() to acpi_get_cpu_acpi_id() on non-x86 To: Bjorn Helgaas , Chengwen Feng References: <20260310175305.GA730372@bhelgaas> Content-Language: en-GB From: Andrew Cooper In-Reply-To: <20260310175305.GA730372@bhelgaas> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ClientProxiedBy: LO2P265CA0131.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:9f::23) To CH8PR03MB8275.namprd03.prod.outlook.com (2603:10b6:610:2b9::7) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH8PR03MB8275:EE_|SJ0PR03MB5518:EE_ X-MS-Office365-Filtering-Correlation-Id: 6ec7f3b8-a59e-49fc-4842-08de7ef5f52f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|1800799024|376014|22082099003|56012099003|18002099003; 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Xen PV dom0 (only, but still widely in use; ring-deprivileging and predates hardware virt) is OSPM for the whole system, seeing the real ACPI tables but with a number of vCPUs generally less than the whole system. This causes Linux to have a split idea of what CPUs are, held together by hope and duct tape. Xen PVH dom0 (hardware virt) is OSPM, but has an MADT matching it's vCPU layout.  It still sees the system DSDT/etc, so while this is better from Linux's point of view, it's still not great. Regular unprivileged VMs get a fully coherent set of CPUID + ACPI tables. ~Andrew