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Tue, 23 Sep 2025 08:16:07 +0000 Date: Tue, 23 Sep 2025 16:15:57 +0800 From: Chao Gao To: Sean Christopherson CC: Paolo Bonzini , , , Tom Lendacky , Mathias Krause , John Allen , Rick Edgecombe , Binbin Wu , Xiaoyao Li , "Maxim Levitsky" , Zhang Yi Z , "Xin Li" Subject: Re: [PATCH v16 24/51] KVM: nVMX: Always forward XSAVES/XRSTORS exits from L2 to L1 Message-ID: References: <20250919223258.1604852-1-seanjc@google.com> <20250919223258.1604852-25-seanjc@google.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20250919223258.1604852-25-seanjc@google.com> X-ClientProxiedBy: SGXP274CA0019.SGPP274.PROD.OUTLOOK.COM (2603:1096:4:b8::31) To CH3PR11MB8660.namprd11.prod.outlook.com (2603:10b6:610:1ce::13) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR11MB8660:EE_|DS0PR11MB7650:EE_ X-MS-Office365-Filtering-Correlation-Id: 106b238c-f2f3-4925-eaf0-08ddfa79728f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|7416014|376014|366016|7053199007; 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KVM always >loads vmcs02 with vmcs12's bitmap, and so any exit _must_ be due to >vmcs12's XSS-bitmap. > >Drop the comment about XSS never being non-zero in anticipation of >enabling CET_KERNEL and CET_USER support. > >Opportunistically WARN if XSAVES is not enabled for L2, as the CPU is >supposed to generate #UD before checking the XSS-bitmap. > >Signed-off-by: Sean Christopherson Reviewed-by: Chao Gao