Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <100d7145-7307-20fc-2cc9-0c2edd08f3ef@amd.com>
Date:   Wed, 2 Aug 2023 09:42:22 +0530
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Reply-To: nikunj@amd.com
Subject: Re: [PATCH v3 05/14] virt: sev-guest: Add vmpck_id to snp_guest_dev
 struct
Content-Language: en-US
To:     Tom Lendacky <thomas.lendacky@amd.com>,
        linux-kernel@vger.kernel.org, x86@kernel.org
Cc:     bp@alien8.de, dionnaglaze@google.com, pgonda@google.com,
        seanjc@google.com, pbonzini@redhat.com
References: <20230722111909.15166-1-nikunj@amd.com>
 <20230722111909.15166-6-nikunj@amd.com>
 <1a4e6652-2e24-955c-5332-da84cced68e4@amd.com>
From:   "Nikunj A. Dadhania" <nikunj@amd.com>
In-Reply-To: <1a4e6652-2e24-955c-5332-da84cced68e4@amd.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Qi9NQSttZFJ2Qng4SEpwMHN5ZjdCdlZtQm1LakZweHpvb2NUTGlybWdjMUJI?=
 =?utf-8?B?VjFaNVJuMTdzU09CT2pvU01lbmtGSTB5eUZXVVNYYnB2d1RGRFkvTHNieno5?=
 =?utf-8?B?NGNzdEdCWDQzNjc1SXJTTnMwTmZUdDhCVlhQZkRXdm1kdGxBa3Q1dUtuWWRo?=
 =?utf-8?B?N2JmYTR6SisxMW9nWlE1VFdHazZvZ2d0S0FmQkVIN2Y4anBSNVNXRFZUM3hL?=
 =?utf-8?B?cCt2YjFyeTdYWnJtOEZoc2tTd3NFemNQeXIrc3V5TnpSV1ZkMEpodlRkTkJh?=
 =?utf-8?B?aVdDNi8yWHhObFRhKytVVHpWMGM2dFZrYVMxeFk5OFVkNUtqM0VXaUxxc3Z4?=
 =?utf-8?B?SWxZZ2p4eHJCalJvMXhUVllMREpVbEwzNFFWYUg1dUpWTVZBZEVRT1IrRDJt?=
 =?utf-8?B?N0NKcUFRMzZhUEloSUFGcmlwM01mUGNPRC81NUtEa2cyNVBKQlpIMkFxb1hu?=
 =?utf-8?B?eUplSmdFVGlsM1BWZ250cWlaNXJtTnFHV3c4WDJVSnBpdHdHTUlXU2dCd0lH?=
 =?utf-8?B?dklRWEc5Q2RISHJNdXRJUU9ybWZuV1hFU2JjeEltYUVsWE5CK0VwVmNvM0Vk?=
 =?utf-8?B?c1dtUmhRN3Z6ZzJ5L1E4YnltSDNDSnFmcHQ4dnJjemh3dGJpN0ZYdkxEWWcy?=
 =?utf-8?B?dDVmQUdtVkUvY29aaGcwSW5vTTlqOTF3WVVWcnJST0EwOHQybDM1NnRlMmV1?=
 =?utf-8?B?NURyMFI3UVlZWEp1eUlZaUxFUjRaU25DQStZSjg3U04rTVhVczhBMEFXcDcv?=
 =?utf-8?B?aXhlOVZLRmJ5bXIxdGpkT3c3THpHN0xaM3hLMUhrcjh4alRGdWN1em92cXB3?=
 =?utf-8?B?RlVnb0dCNUl6RjljY3ZYa2dFaDlETHVwenZsR0ExWkpOeVd6MlhtTW1QQ2FN?=
 =?utf-8?B?czFJMW0xT1ZpTHFSbFpEMmxnMlR6blU0ZW5RR1ozbFptdkhmOTBnLzdqaHU2?=
 =?utf-8?B?K3R6WHpoUmtaNmdIUGFvQlhMZnI5YlBYeVp2OHV0Z3prSGcxNURlQnR4WWZO?=
 =?utf-8?B?bTJzNE9pK2tGNHRlY0hsOVRmU0prVlpmZFllZVlUc1F4QVoyRU9Nbmc1b0po?=
 =?utf-8?B?S05WTGo4UTAxVXN2WmlqWFRsVUx2dW9GQ2wxK0p2T0lJVTM2Uk9YVG81UXRa?=
 =?utf-8?B?Ykw5U2pCajJHbElQU1BVa2pRQkdyMG9NZXlNeXpIbWdKZHFmRGkvWXBNUVdZ?=
 =?utf-8?B?b0NFSCtlRk5MZmZQekV3U2JwenZGaFFsK2s2NzFFUjgvZHhBOEE0UCtnMG8y?=
 =?utf-8?B?bnF2ZEZTNHE5ay85UXdPK3pQU1YvMjRsa1o1RUVzbUFRdTdBVEdoRDMxY2Jt?=
 =?utf-8?B?dkxLbGluMkd5dU4yaEpsb2hxZU82VS9CQjVLcmJEeUtjZ2pUTnRjZE5Pb3pU?=
 =?utf-8?B?UDN0V2RjR1pYMkZYb3dWcUFGa3BwWUwvbGxEQUM5UFQvZkZqY0J2ZVFPTUZs?=
 =?utf-8?B?Q3FKR1oydzIrYVNFYzAwam1ER1JzNWYvamd2SkxveUY1UENFQzBlcDFoeVRL?=
 =?utf-8?B?V2s5NERBK0crSlRPNGFIQ093di95YWpLR1VOUXFWQnBOYkpZdEREMjBSc1Qv?=
 =?utf-8?B?S01BOS9RaEo2T3dQREFyNVd1Z3NNaWlxb1FGUnJReFhubDhteVZiOGdLaXFz?=
 =?utf-8?B?RldRbk8zYWc5YjRBNnVvNDg1a0dUOGoxSzd3ZEFYMnZrNW1VTFFQL2duQVAw?=
 =?utf-8?B?ZmwzRVRVU2VVSUYzRllZVEtBN0oxbFl1OWVlRWlLRG1hbU5ST0I1UnZjSUR1?=
 =?utf-8?B?ZVFFeTdqSkJlM095OThHVFhka0NmTW1QaXk5allvR1ZOc1dSVWF2ZE9ycTV2?=
 =?utf-8?B?SEpYS0J5VmkvYkJxNFZpOTdVaDQyN0JmdUhSL1pXbVBzUExIOEsrWHZ4MnBN?=
 =?utf-8?B?blBNaUtubW5YOHBOeHBxRXJVSkRCZU1vNVNXVzQyWTFhb1dhbktwanJ1K1d5?=
 =?utf-8?B?cFBvWGNGZ2pzTVNVd2RJQ3BJUlpYbG1HQ3A1cGsvVWsyb21KaHdFQ2ZIQ0p0?=
 =?utf-8?B?Y0ZQL0RwZkJUeG8yUkRjb3VzT093WTBJdHBGYUorTTgwcWhFeGU5QU8vNGlv?=
 =?utf-8?B?OTJBZFFiNjNXWGdKM2NkUlVCR1dzaDNldnlYWXdzOFdMWnpOUlV4NUtPYy80?=
 =?utf-8?Q?L/v9YZtVF8sWVYClMGilTYdyu?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: bbfcc3b8-56cc-4372-7206-08db930eb36d
X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB6309.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Aug 2023 04:12:35.5954
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 2hYiNby4bUi5osPIx71XzU/gkJTKdXvwc5810EYwfYpHFtw8BVBCjOoOvsoN71p02nyFmjGQ1li5+Gkv9vm9Xg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY5PR12MB6059
X-Spam-Status: No, score=-1.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,NICE_REPLY_A,
        RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_NONE,
        T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=no autolearn_force=no
        version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 8/1/2023 10:00 PM, Tom Lendacky wrote:
> On 7/22/23 06:19, Nikunj A Dadhania wrote:
>> Drop vmpck and os_area_msg_seqno pointers so that secret page layout
>> does not need to be exposed to the sev-guest driver after the rework.
>> Instead, add helper APIs to access vmpck and os_area_msg_seqno when
>> needed.
>>
>> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
>> ---
>>   drivers/virt/coco/sev-guest/sev-guest.c | 84 +++++++++++++------------
>>   1 file changed, 43 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
>> index d4241048b397..8ad43e007d3b 100644
>> --- a/drivers/virt/coco/sev-guest/sev-guest.c
>> +++ b/drivers/virt/coco/sev-guest/sev-guest.c
>> @@ -50,8 +50,7 @@ struct snp_guest_dev {
>>         struct snp_secrets_page_layout *layout;
>>       struct snp_req_data input;
>> -    u32 *os_area_msg_seqno;
>> -    u8 *vmpck;
>> +    unsigned int vmpck_id;
>>   };
>>     static u32 vmpck_id;
>> @@ -67,12 +66,23 @@ static inline unsigned int get_ctx_authsize(struct snp_guest_dev *snp_dev)
>>       return 0;
>>   }
>>   -static bool is_vmpck_empty(struct snp_guest_dev *snp_dev)
>> +static inline u8 *snp_get_vmpck(struct snp_guest_dev *snp_dev)
>> +{
>> +    return snp_dev->layout->vmpck0 + snp_dev->vmpck_id * VMPCK_KEY_LEN;
>> +}
>> +
>> +static inline u32 *snp_get_os_area_msg_seqno(struct snp_guest_dev *snp_dev)
>> +{
>> +    return &snp_dev->layout->os_area.msg_seqno_0 + snp_dev->vmpck_id;
>> +}
>> +
>> +static bool snp_is_vmpck_empty(struct snp_guest_dev *snp_dev)
> 
> I noticed this name change from is_vmpck_empty() to snp_is_vmpck_empty(). Is that in prep for moving, too? Is so, maybe call that out in the commit message.

Yes, will add to the  commit.

> 
>>   {
>>       char zero_key[VMPCK_KEY_LEN] = {0};
>> +    u8 *key = snp_get_vmpck(snp_dev);
>>   -    if (snp_dev->vmpck)
>> -        return !memcmp(snp_dev->vmpck, zero_key, VMPCK_KEY_LEN);
>> +    if (key)
>> +        return !memcmp(key, zero_key, VMPCK_KEY_LEN);
> 
> I believe key can't be NULL, so this check isn't required.

Sure, will update.

Regards
Nikunj