Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
Message-ID: <afc3e286-5a2d-62e8-e55e-b95ebe4373f4@amd.com>
Date:   Mon, 30 Oct 2023 14:19:38 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [PATCH v5 08/14] x86/mm: Add generic guest initialization hook
Content-Language: en-US
To:     Nikunj A Dadhania <nikunj@amd.com>, linux-kernel@vger.kernel.org,
        x86@kernel.org, kvm@vger.kernel.org
Cc:     bp@alien8.de, mingo@redhat.com, tglx@linutronix.de,
        dave.hansen@linux.intel.com, dionnaglaze@google.com,
        pgonda@google.com, seanjc@google.com, pbonzini@redhat.com
References: <20231030063652.68675-1-nikunj@amd.com>
 <20231030063652.68675-9-nikunj@amd.com>
From:   Tom Lendacky <thomas.lendacky@amd.com>
In-Reply-To: <20231030063652.68675-9-nikunj@amd.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ckp4WEZVck12NEhtY3JXaU8rS1dpTGJudmpwOUdjWHRvQys0dXI5TnZ3eUFX?=
 =?utf-8?B?QkZsallrWWpHRlpveU5Cb1dsL1A5dXdiV3VxdFNnZHpYQ0pTcktUR2dCNmFD?=
 =?utf-8?B?Njd6OGgyaG0wVGlFNi9yWlp1YmIwTm13TUdSS0VDUWw5dWhrcGhlc3hUMEVY?=
 =?utf-8?B?eCtEd2RxQnZ2RVF5TTJqNmUzSFh2cm5Xc2tkTkFNdmI4MUpIS2FtMUxhU1Ey?=
 =?utf-8?B?ZUFnbWlSRVhEbGFidDlyWTlnNE45ZmdTYmdVMVVtejlwS0liL25GVS9HeU1r?=
 =?utf-8?B?Yml5dWxNdGVqbGQ4bE9zUngrazZmRUtDMG5Yc3oxTTVrd1hJLy93cFpacjdM?=
 =?utf-8?B?dlRqMmgxNEpmbm1NRG1BN04ySG9WOXJNaGhkdExQMERySHpYUHhHM3F4MFc5?=
 =?utf-8?B?Um1aUGkyWkxId2FndlNiaUJlUUZNMTg5L2tZMXlLeE5YcmpMT2tJMnVaTytu?=
 =?utf-8?B?Wll6NEhJaHEwUDFVT0hOelVNV2d4SEpaRWFZTlZmeVd1b09LVFIxSVJYcGpv?=
 =?utf-8?B?Y3lsbzRwbG9sdW1NakFtUzNwZytrU2I2K0VBRlZqWmZuU1d5Q1hYVmxkUit2?=
 =?utf-8?B?YklRWTQvSW0rcGFsTEp4Q0lrbnBRUml0ZjBRRnJSTWNZdTgwRDZLU0ZUMk1s?=
 =?utf-8?B?WVc4UkVqSi9HR3hkaGtqWVJIQ0pxcGtCenBDekdKbnRPR0dlVGN1NWQzSE1v?=
 =?utf-8?B?N3JvT085aHNoT2lNd1lnRjNWMVZZb3o0YlJHMWJyRzIwbzNvTGRiZkJyQnBn?=
 =?utf-8?B?VDcxcDNoSFBwOG1pZlo4SkJyUmVkTFUyQkpjYW51NndnS0pIS3A3ZWp0ZWlC?=
 =?utf-8?B?U2JzYTF5ZXJOb1NWV0NBZkd1M1pwU0JvbzhRN1hEanRuRnJiTWtXWHpFVExj?=
 =?utf-8?B?aThKamY4Y2NaYTZKcXNyb01ZeEttNVpWVVovSFRrZnprdW9QeFdzbzNTbkhX?=
 =?utf-8?B?aXJ5L3BoR3AyNzVSQ0l3RFdkY3ozUDJvQlI2NVlPZTluWWcvYkY3aS92anN3?=
 =?utf-8?B?bFZzaUc0YnJMOGltWFA5ejJHUUttTkNKSlVVWUNkcXJOYzgzN3MrK3FJS2d1?=
 =?utf-8?B?RVYzell4SzdwU2R3YzJmNlVsZVp4OFF3MHdTZzVRTXlJdDQ0QTFmNElRclk3?=
 =?utf-8?B?Z0dCeG1KejU0OE1aSm1DVEsrekl0WUs3T0YwRGpFaERaelJtZ2dRUjRpZ2xB?=
 =?utf-8?B?K25jTE1hMkszU0Nad3FXR1IrSFBiQWVkejRLekpndXZISkovRVJmT0ErWmpj?=
 =?utf-8?B?cUhCcHJkakF1am9keWQzQVFYL0lURDRNaWhoMFBkcFQ5ZzVVVkQvVFBDUDFa?=
 =?utf-8?B?aVh4NmZtcHdRZXNOQWhUMnVTVGtiNWtLK1I2S0NnUHRXeEVlYm5vdkZZZGxK?=
 =?utf-8?B?aUtEZ0srcDFxT3UvUlFTditoK0wzOE95ZWhGTzhEY1N0NHZRTmV6UGh6L0g1?=
 =?utf-8?B?U2xRYlowSnBTd29UQUxCOTRMT1FuN1ZZNTMzczMwUWNFNFJPMis4dmZGTDdB?=
 =?utf-8?B?Z3E0Qk9XelppZWY0S0RPTVd0UE9ZLy91bEdjclhLNDBTWGh4MEhKSElmcWZo?=
 =?utf-8?B?ZFRabDlNTUkvcXBZMkFlYzJEdE43dGdFQ2pZWHpyWUpqZXRTYmxoRUZtbzls?=
 =?utf-8?B?Q0J5TzVaeElsSkdoRlVYbmc4SElDOC9GejNUUWtHemZzQ09zRTVuYit0bzgy?=
 =?utf-8?B?TnpOM3BDc3hZditBUWpJZEI1enhRTm43SENpN3JrcVNSMDFqenYxTUpPSTJx?=
 =?utf-8?B?QncxT2xzaGhEbFdTZVdpT3Y2STEzQnVZMzNiVy9DUVpKZ0p2T2tucm5MWlFI?=
 =?utf-8?B?Vy93WWlPS2s3RW1Jek01aTlhMEZuWm93V3AvOUR4Ukd4MlpqOFFCUERSenhz?=
 =?utf-8?B?NHRydHBvY1QwN2VjM2wza0xoMzRPTDZOOEFSV3g2ZytZSkdyOW9OZFNtTkFH?=
 =?utf-8?B?bGJ5LzM3UVRycGtnY2p0YUxMVDFwQTdJdjEyZlFiNDVNMERpZ1VFcUMxWmhW?=
 =?utf-8?B?QW5QYWc0bzh5N1ZQbm5TOU1xNEtSRitDdnpuVUN3VlNCTThEUURWVTNwSU4y?=
 =?utf-8?B?UVp5R2VCcFY1czdGS0hsVWFJTEMyUC9FTmpjSzZMK1dXVW96Z3dtWEJjSmRk?=
 =?utf-8?Q?BwTmhJd5bqgePe6jPfClgTdAq?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: d883cb7f-47f7-4938-118f-08dbd97d2acd
X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5732.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Oct 2023 19:19:41.6782
 (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: KL3IuljxZZiWtpX5jlDpGu1EhLK9cFsSla/wPUqh5rjtBcGcu/+wstVWq+euCEYvxO3ci+Mh2D2VyTmlxgA90w==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR12MB7866
X-Spam-Status: No, score=-5.8 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on fry.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (fry.vger.email [0.0.0.0]); Mon, 30 Oct 2023 12:20:02 -0700 (PDT)

On 10/30/23 01:36, Nikunj A Dadhania wrote:
> Add generic enc_init guest hook for performing any type of
> initialization that is vendor specific.

I think this commit message should be expanded on a bit... like when it is 
intended to be called, etc.

Thanks,
Tom

> 
> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
> ---
>   arch/x86/include/asm/x86_init.h | 2 ++
>   arch/x86/kernel/x86_init.c      | 2 ++
>   arch/x86/mm/mem_encrypt.c       | 3 +++
>   3 files changed, 7 insertions(+)
> 
> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
> index 5240d88db52a..6a08dcd1f3c4 100644
> --- a/arch/x86/include/asm/x86_init.h
> +++ b/arch/x86/include/asm/x86_init.h
> @@ -148,12 +148,14 @@ struct x86_init_acpi {
>    * @enc_status_change_finish	Notify HV after the encryption status of a range is changed
>    * @enc_tlb_flush_required	Returns true if a TLB flush is needed before changing page encryption status
>    * @enc_cache_flush_required	Returns true if a cache flush is needed before changing page encryption status
> + * @enc_init			Prepare and initialize encryption features
>    */
>   struct x86_guest {
>   	bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
>   	bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
>   	bool (*enc_tlb_flush_required)(bool enc);
>   	bool (*enc_cache_flush_required)(void);
> +	void (*enc_init)(void);
>   };
>   
>   /**
> diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
> index a37ebd3b4773..a07985a96ca5 100644
> --- a/arch/x86/kernel/x86_init.c
> +++ b/arch/x86/kernel/x86_init.c
> @@ -136,6 +136,7 @@ static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool
>   static bool enc_tlb_flush_required_noop(bool enc) { return false; }
>   static bool enc_cache_flush_required_noop(void) { return false; }
>   static bool is_private_mmio_noop(u64 addr) {return false; }
> +static void enc_init_noop(void) { }
>   
>   struct x86_platform_ops x86_platform __ro_after_init = {
>   	.calibrate_cpu			= native_calibrate_cpu_early,
> @@ -158,6 +159,7 @@ struct x86_platform_ops x86_platform __ro_after_init = {
>   		.enc_status_change_finish  = enc_status_change_finish_noop,
>   		.enc_tlb_flush_required	   = enc_tlb_flush_required_noop,
>   		.enc_cache_flush_required  = enc_cache_flush_required_noop,
> +		.enc_init		   = enc_init_noop,
>   	},
>   };
>   
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 9f27e14e185f..01abecc9a774 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -84,5 +84,8 @@ void __init mem_encrypt_init(void)
>   	/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
>   	swiotlb_update_mem_attributes();
>   
> +	if (x86_platform.guest.enc_init)
> +		x86_platform.guest.enc_init();
> +
>   	print_mem_encrypt_feature_info();
>   }