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Date: Tue, 23 Apr 2024 10:04:42 +0530
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Reply-To: nikunj@amd.com
Subject: Re: [PATCH v8 08/16] x86/mm: Add generic guest initialization hook
To: Borislav Petkov <bp@alien8.de>
Cc: linux-kernel@vger.kernel.org, thomas.lendacky@amd.com, x86@kernel.org,
 kvm@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de,
 dave.hansen@linux.intel.com, pgonda@google.com, seanjc@google.com,
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References: <20240215113128.275608-1-nikunj@amd.com>
 <20240215113128.275608-9-nikunj@amd.com>
 <20240422132058.GBZiZkOqU0zFviMzoC@fat_crate.local>
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From: "Nikunj A. Dadhania" <nikunj@amd.com>
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On 4/22/2024 6:50 PM, Borislav Petkov wrote:
> On Thu, Feb 15, 2024 at 05:01:20PM +0530, Nikunj A Dadhania wrote:
>> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
>> index d035bce3a2b0..68aa06852466 100644
>> --- a/arch/x86/mm/mem_encrypt.c
>> +++ b/arch/x86/mm/mem_encrypt.c
>> @@ -89,6 +89,8 @@ void __init mem_encrypt_init(void)
>>  	/* Call into SWIOTLB to update the SWIOTLB DMA buffers */
>>  	swiotlb_update_mem_attributes();
>>  
>> +	x86_platform.guest.enc_init();
>> +
>>  	print_mem_encrypt_feature_info();
> 
> Why all this hoopla if all you need is to call it once in mem_encrypt.c?

This was added thinking in mind that any SNP/TDX init can happen in this hook.

> IOW, you can simply call snp_secure_tsc_prepare() there, no?

Yes, that is very simple, will drop this change.

> Those function pointers are to be used in generic code in order to hide
> all the platform-specific hackery but mem_encrypt.c is not really
> generic code, I'd say...
> 

Sure.

Regards
Nikunj