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Date:   Thu, 9 Nov 2023 17:35:39 +0100
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Subject: Re: [PATCH] x86/mm: Check cc_vendor when printing memory encryption
 info
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To:     Dave Hansen <dave.hansen@intel.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
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        linux-kernel@vger.kernel.org,
        Michael Kelley <mhklinux@outlook.com>,
        Dexuan Cui <decui@microsoft.com>
Cc:     linux-hyperv@vger.kernel.org, stefan.bader@canonical.com,
        tim.gardner@canonical.com, roxana.nicolescu@canonical.com,
        cascardo@canonical.com, kys@microsoft.com, haiyangz@microsoft.com,
        wei.liu@kernel.org, kirill.shutemov@linux.intel.com,
        sashal@kernel.org
References: <1699546489-4606-1-git-send-email-jpiotrowski@linux.microsoft.com>
 <16ea75a9-8c94-4665-ae04-32d08aa4ebb2@intel.com>
From:   Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
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On 09/11/2023 17:25, Dave Hansen wrote:
> On 11/9/23 08:14, Jeremi Piotrowski wrote:
> ...
>>  	pr_info("Memory Encryption Features active:");
>>  
>> -	if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) {
>> +	if (cc_vendor == CC_VENDOR_INTEL) {
>>  		pr_cont(" Intel TDX\n");
>>  		return;
>>  	}
> 
> Why aren't these guests setting X86_FEATURE_TDX_GUEST?

They could if we can confirm that the code gated behind
cpu_feature_enabled(X86_FEATURE_TDX_GUEST) is correct when running with TD partitioning.

It still makes sense to have these prints based on the cc_xxx abstractions.

Jeremi