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From: Tom Lendacky <thomas.lendacky@amd.com>
To: Borislav Petkov <bp@alien8.de>, Michael Roth <michael.roth@amd.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Sean Christopherson <seanjc@google.com>,
	stable@kernel.org
Subject: Re: [PATCH] x86/sev: Guard sev_evict_cache() with CONFIG_AMD_MEM_ENCRYPT
Date: Sat, 13 Sep 2025 09:29:47 -0500	[thread overview]
Message-ID: <56877590-a7c8-4dbd-b334-ae9cbbf62bf1@amd.com> (raw)
In-Reply-To: <20250912210201.GFaMSKSSvK55XIwR3e@fat_crate.local>

On 9/12/25 16:02, Borislav Petkov wrote:
> On Fri, Sep 12, 2025 at 03:49:29PM -0500, Michael Roth wrote:
>> I think that's actually the concerning thing. If someone built a guest
>> kernel with CONFIG_KVM_AMD_SEV=y they might be under the impression that
>> this is performing evictions when it's actually just a stub function.
> 
> That sooo needs to be in the commit message...

I can send a v2 or if you want to modify the commit message with the
following:

 The sev_evict_cache() is guest-related code and should be guarded by
 CONFIG_AMD_MEM_ENCRYPT, not CONFIG_KVM_AMD_SEV.

 CONFIG_AMD_MEM_ENCRYPT=y is required for a guest to run properly as an
 SEV-SNP guest, but a guest kernel built with CONFIG_KVM_AMD_SEV=n would
 get the stub function of sev_evict_cache() instead of the version that
 performs the actual eviction. Move the function declarations under the
 appropriate #ifdef.

Let me know.

Thanks,
Tom

> 


  reply	other threads:[~2025-09-13 14:29 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-12 20:29 Tom Lendacky
2025-09-12 20:39 ` Michael Roth
2025-09-12 20:42 ` Borislav Petkov
2025-09-12 20:49   ` Michael Roth
2025-09-12 21:02     ` Borislav Petkov
2025-09-13 14:29       ` Tom Lendacky [this message]
2025-09-13 15:38         ` Borislav Petkov

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