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Date:   Fri, 7 Jul 2023 10:57:12 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Joerg Roedel <jroedel@suse.de>, michael.roth@amd.com
Cc:     Baoquan He <bhe@redhat.com>, Tao Liu <ltao@redhat.com>,
        thomas.lendacky@amd.com, tglx@linutronix.de, mingo@redhat.com,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        ardb@kernel.org, linux-kernel@vger.kernel.org, dyoung@redhat.com,
        kexec@lists.infradead.org, linux-efi@vger.kernel.org
Subject: Re: [PATCH v2] x86/kexec: Add EFI config table identity mapping for
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On Fri, Jul 07, 2023 at 10:22:56AM +0200, Joerg Roedel wrote:
> On Fri, Jul 07, 2023 at 12:23:59PM +0800, Baoquan He wrote:
> > I am wondering why we don't detect the cpu type and return early inside
> > sev_enable() if it's Intel cpu.
> > 
> > We can't rely on CONFIG_AMD_MEM_ENCRYPT to decide if the code need be
> > executed or not because we usually enable them all in distros.
> 
> Looking at the code in head_64.S, by the time sev_enable() runs the SEV
> bit should already be set in sev_status. Maybe use that to detect
> whether SEV is enabled and bail out early?

There was something about getting the CPUID page on SNP *before*
actually calling CPUID but this is not the first time we had trouble in
this area. This needs to be done differently.

Michael?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette