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b=V7D8BXKw9+jvBDgJT7CXKG4GJ5wGZvbkAd5GEK+2QXGIAyYI2y5rSSCB5N9ODwaVnoj094N4kiD4kSDqKAYQxwiBT/vSk2WZPbWfUF3PNjR3eBLQwwKfho4cdxAPf/oEluHhbvuIHpzWASVPX8tr4DiY7c/DxFofWxVzap6TP+0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BL3PR12MB9049.namprd12.prod.outlook.com (2603:10b6:208:3b8::21) by DM6PR12MB4451.namprd12.prod.outlook.com (2603:10b6:5:2ab::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9052.16; Thu, 21 Aug 2025 10:59:00 +0000 Received: from BL3PR12MB9049.namprd12.prod.outlook.com ([fe80::ae6a:9bdd:af5b:e9ad]) by BL3PR12MB9049.namprd12.prod.outlook.com ([fe80::ae6a:9bdd:af5b:e9ad%6]) with mapi id 15.20.8989.018; Thu, 21 Aug 2025 10:58:59 +0000 Message-ID: Date: Thu, 21 Aug 2025 05:58:56 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 2/2] KVM: SEV: Add SEV-SNP CipherTextHiding support To: Kim Phillips , Randy Dunlap , corbet@lwn.net, seanjc@google.com, pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, thomas.lendacky@amd.com, herbert@gondor.apana.org Cc: akpm@linux-foundation.org, rostedt@goodmis.org, paulmck@kernel.org, michael.roth@amd.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <95abc49edfde36d4fb791570ea2a4be6ad95fd0d.1755721927.git.ashish.kalra@amd.com> <5dff05c1-474e-4fff-a19b-7c17b4db6173@infradead.org> <7eed1970-4e7d-4b3a-a3c1-198b0a6521d5@amd.com> <922eaff1-b2dc-447c-9b9c-ac1281ee000d@amd.com> Content-Language: en-US From: "Kalra, Ashish" In-Reply-To: <922eaff1-b2dc-447c-9b9c-ac1281ee000d@amd.com> Content-Type: text/plain; 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>>>> + >>>> +        if (sev_is_snp_ciphertext_hiding_supported()) >>>> +            init_args.max_snp_asid = min(nr_ciphertext_hiding_asids, >>>> +                             min_sev_asid - 1); >>>> + >>>>           if (sev_platform_init(&init_args)) >>>>               sev_supported = sev_es_supported = sev_snp_supported = false; >>>>           else if (sev_snp_supported) >>>>               sev_snp_supported = is_sev_snp_initialized(); >>>> + >>>> +        if (sev_snp_supported) >>>> +            nr_ciphertext_hiding_asids = init_args.max_snp_asid; >>>> + >>>> +        /* >>>> +         * If ciphertext hiding is enabled, the joint SEV-ES/SEV-SNP >>>> +         * ASID range is partitioned into separate SEV-ES and SEV-SNP >>>> +         * ASID ranges, with the SEV-SNP range being [1..max_snp_asid] >>>> +         * and the SEV-ES range being [max_snp_asid..max_sev_es_asid]. >>>                                       [max_snp_asid + 1..max_sev_es_asid] >>> ? >> Yes. > > So why wouldn't you have left Sean's original "(max_snp_asid..max_sev_es_asid]" as-is? > > Kim > Because that i believe is a typo and the correct SEV-ES range is [max_snp_asid + 1..max_sev_es_asid]. Ashish