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Wysocki" , Viresh Kumar , Borislav Petkov , Jason Andryuk Cc: Michael Kelley , Michael Kelley , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, "Mario Limonciello (AMD)" References: <20260722-amd-pstate-vm-v4-1-d6607d9e9d9a@rong.moe> From: Mario Limonciello In-Reply-To: <20260722-amd-pstate-vm-v4-1-d6607d9e9d9a@rong.moe> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SA9PR13CA0154.namprd13.prod.outlook.com (2603:10b6:806:28::9) To PH8PR12MB6914.namprd12.prod.outlook.com (2603:10b6:510:1cb::21) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH8PR12MB6914:EE_|CYXPR12MB9388:EE_ X-MS-Office365-Filtering-Correlation-Id: 0c92eb7c-7069-47a3-358c-08dee755323e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|366016|1800799024|376014|3023799007|10067099003|56012099006|11063799006|18002099003|22082099003; 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Without it, the driver is unusable and thus will not > load. This check also prevents the driver from loading in guests and > thus not confuse users with misleading prints. > > Reviewed-by: Michael Kelley > Tested-by: Michael Kelley > Acked-by: Mario Limonciello (AMD) > Reviewed-by: K Prateek Nayak > Tested-by: K Prateek Nayak > Acked-by: Borislav Petkov (AMD) > Signed-off-by: Rong Zhang > --- Thanks, will include it in a PR this week. > Changes in v4: > - Clean up the commit message (thanks Borislav Petkov) > - Drop the Fixes: tag (ditto) > - Link to v3: https://patch.msgid.link/20260721-amd-pstate-vm-v3-1-8b59574fb714@rong.moe > > Changes in v3: > - Move the check into amd_cppc_supported() and add a pr_debug_once() > message (thanks K Prateek Nayak and Mario Limonciello) > - The check is added before the existing family 17h model 0h-2Fh one, > as print_cpu_info() already shows family, model, and stepping, and > will help debugging even if the new check overrides the existing > one, but not vice versa > - Link to v2: https://patch.msgid.link/20260718-amd-pstate-vm-v2-1-6ed5f3b2c89e@rong.moe > > Changes in v2: > - Check for X86_FEATURE_HW_PSTATE instead of X86_FEATURE_HYPERVISOR > (thanks K Prateek Nayak) > - Remove the check against Xen dom0, as it doesn't need the amd-pstate > driver (thanks Jason Andryuk) > - Reword comments and the commit message > - Remove Gautham R. Shenoy from the To list due to email bounces > - Link to v1: https://patch.msgid.link/20260716-amd-pstate-vm-v1-1-2ac97d3cf6e7@rong.moe > --- > drivers/cpufreq/amd-pstate.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c > index a74a4cf99d22..b0b651380732 100644 > --- a/drivers/cpufreq/amd-pstate.c > +++ b/drivers/cpufreq/amd-pstate.c > @@ -2167,6 +2167,7 @@ static struct cpufreq_driver amd_pstate_epp_driver = { > }; > > /* > + * Processors without frequency scaling support can't do CPPC. > * CPPC function is not supported for family ID 17H with model_ID ranging from 0x10 to 0x2F. > * show the debug message that helps to check if the CPU has CPPC support for loading issue. > */ > @@ -2175,6 +2176,11 @@ static bool amd_cppc_supported(void) > struct cpuinfo_x86 *c = &cpu_data(0); > bool warn = false; > > + if (!cpu_feature_enabled(X86_FEATURE_HW_PSTATE)) { > + pr_debug_once("frequency scaling is not supported by the processor\n"); > + return false; > + } > + > if ((boot_cpu_data.x86 == 0x17) && (boot_cpu_data.x86_model < 0x30)) { > pr_debug_once("CPPC feature is not supported by the processor\n"); > return false; > > --- > base-commit: 248951ddc14de84de3910f9b13f51491a8cd91df > change-id: 1cc24037-amd-pstate-vm-d6ab4c959bd3 > > Thanks, > Rong >