Re: [PATCH v2 3/4] EFI: Introduce the new AMD Memory Encryption GUID.

From: Ard Biesheuvel <ardb@kernel.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Ashish Kalra <Ashish.Kalra@amd.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Joerg Roedel <joro@8bytes.org>,
	Tom Lendacky <thomas.lendacky@amd.com>, X86 ML <x86@kernel.org>,
	kvm@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	srutherford@google.com, Sean Christopherson <seanjc@google.com>,
	venu.busireddy@oracle.com, Brijesh Singh <brijesh.singh@amd.com>,
	linux-efi <linux-efi@vger.kernel.org>
Subject: Re: [PATCH v2 3/4] EFI: Introduce the new AMD Memory Encryption GUID.
Date: Wed, 12 May 2021 16:53:21 +0200	[thread overview]
Message-ID: <CAMj1kXE0U4JxCLYPhetENDpXKMOAEXs8-dpce+CvBcgifQz2Ww@mail.gmail.com> (raw)
In-Reply-To: <YJvV9yKclJWLppWU@zn.tnic>

On Wed, 12 May 2021 at 15:19, Borislav Petkov <bp@alien8.de> wrote:
>
> On Fri, Apr 23, 2021 at 03:59:01PM +0000, Ashish Kalra wrote:
> > From: Ashish Kalra <ashish.kalra@amd.com>
> >
> > Introduce a new AMD Memory Encryption GUID which is currently
> > used for defining a new UEFI environment variable which indicates
> > UEFI/OVMF support for the SEV live migration feature. This variable
> > is setup when UEFI/OVMF detects host/hypervisor support for SEV
> > live migration and later this variable is read by the kernel using
> > EFI runtime services to verify if OVMF supports the live migration
> > feature.
> >
> > Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> > ---
> >  include/linux/efi.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/include/linux/efi.h b/include/linux/efi.h
> > index 8710f5710c1d..e95c144d1d02 100644
> > --- a/include/linux/efi.h
> > +++ b/include/linux/efi.h
> > @@ -360,6 +360,7 @@ void efi_native_runtime_setup(void);
> >
> >  /* OEM GUIDs */
> >  #define DELLEMC_EFI_RCI2_TABLE_GUID          EFI_GUID(0x2d9f28a2, 0xa886, 0x456a,  0x97, 0xa8, 0xf1, 0x1e, 0xf2, 0x4f, 0xf4, 0x55)
> > +#define MEM_ENCRYPT_GUID                     EFI_GUID(0x0cf29b71, 0x9e51, 0x433a,  0xa3, 0xb7, 0x81, 0xf3, 0xab, 0x16, 0xb8, 0x75)
> >
> >  typedef struct {
> >       efi_guid_t guid;
> > --
>
> When you apply this patch locally, you do:
>
> $ git log -p -1 | ./scripts/get_maintainer.pl
> Ard Biesheuvel <ardb@kernel.org> (maintainer:EXTENSIBLE FIRMWARE INTERFACE (EFI))
> linux-efi@vger.kernel.org (open list:EXTENSIBLE FIRMWARE INTERFACE (EFI))
> linux-kernel@vger.kernel.org (open list)
>
> and this tells you that you need to CC EFI folks too.
>
> I've CCed linux-efi now - please make sure you use that script to CC the
> relevant parties on patches, in the future.
>

Thanks Boris.

You are adding this GUID to the 'OEM GUIDs' section, in which case I'd
prefer the identifier to include which OEM.

Or alternatively, put it somewhere else, but in this case, putting
something like AMD_SEV in the identifier would still help to make it
more self-documenting.

Thanks,
Ard.