linux-kernel - Re: [PATCH] x86/mm: Fix memory encryption features advertisement

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Message-ID: <20240111104253.fzfjl6z4j3nup6cj@box.shutemov.name>
Date: Thu, 11 Jan 2024 13:42:53 +0300
From: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
To: Tom Lendacky <thomas.lendacky@....com>
Cc: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	Dexuan Cui <decui@...rosoft.com>,
	Jeremi Piotrowski <jpiotrowski@...ux.microsoft.com>
Subject: Re: [PATCH] x86/mm: Fix memory encryption features advertisement

On Wed, Jan 10, 2024 at 03:33:13PM -0600, Tom Lendacky wrote:
> On 1/10/24 13:35, Kirill A. Shutemov wrote:
> > When memory encryption is enabled, the kernel prints the encryption
> > flavor that the system supports.
> > 
> > The check assumes that everything is AMD SME/SEV if it has the TDX CPU
> 
> s/if it has/if it doesn't have/

Oopsie.

> > feature set.
> > 
> > To avoid confusion, check the cc_vendor directly.
> 
> Is this because of the setting of cc_vendor in hv_vtom_init() without
> setting the TDX feature and so "Intel TDX" isn't printed and instead "AMD"
> is printed?
> 
> If so, the commit message should really have some info about how this
> relates to Hyper-V isolation VMs.

That's one of the issue. But the code is generally has flawed logic that
worth addressing.

Will send v2 with better commit message.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov