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From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sat, 24 Feb 2024 02:14:55 +0100
Message-ID: <CAHmME9oN+7rbLYcvQN=+KMjwrokvARy_7khLWJvDK=K_S5uHqg@mail.gmail.com>
Subject: Re: [PATCH v4] x86/coco: Require seeding RNG with RDRAND on CoCo systems
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86@kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, 
	Borislav Petkov <bp@alien8.de>, =?UTF-8?Q?Daniel_P_=2E_Berrang=C3=A9?= <berrange@redhat.com>, 
	Dave Hansen <dave.hansen@linux.intel.com>, "H . Peter Anvin" <hpa@zytor.com>, 
	Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@linutronix.de>, stable@vger.kernel.org, 
	Elena Reshetova <elena.reshetova@intel.com>, 
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, "Theodore Ts'o" <tytso@mit.edu>
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Hi Tom,

On Fri, Feb 23, 2024 at 11:05=E2=80=AFPM Tom Lendacky <thomas.lendacky@amd.=
com> wrote:
>
> On 2/21/24 20:05, Jason A. Donenfeld wrote:
> > +
> > +     if (cc_vendor =3D=3D CC_VENDOR_NONE)
>
> I responded to an earlier version of this patch, adding that response her=
e:
>
> You probably want to use:
>
>      if (!cc_platform_has(CC_GUEST_MEM_ENCRYPT))
>          return;
>
> Otherwise, you can hit the bare-metal case where AMD SME is active and
> then cc_vendor will not be CC_VENDOR_NONE.

Nice catch, thanks. I'll do that for v+1.


Jason