Date:   Wed, 17 Nov 2021 14:11:20 +0100
From:   Borislav Petkov <bp@alien8.de>
To:     Michael Roth <michael.roth@amd.com>
Cc:     Brijesh Singh <brijesh.singh@amd.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org,
        linux-coco@lists.linux.dev, linux-mm@kvack.org,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ard Biesheuvel <ardb@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Jim Mattson <jmattson@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        David Rientjes <rientjes@google.com>,
        Dov Murik <dovmurik@linux.ibm.com>,
        Tobin Feldman-Fitzthum <tobin@ibm.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Kirill A . Shutemov" <kirill@shutemov.name>,
        Andi Kleen <ak@linux.intel.com>,
        "Dr . David Alan Gilbert" <dgilbert@redhat.com>,
        tony.luck@intel.com, marcorr@google.com,
        sathyanarayanan.kuppuswamy@linux.intel.com
Subject: Re: [PATCH v7 02/45] x86/sev: detect/setup SEV/SME features earlier
 in boot
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References: <20211110220731.2396491-1-brijesh.singh@amd.com>
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 <YZKxCdhaFTTlSHAJ@zn.tnic>
 <20211115201715.gv24iugujwhxmrdp@amd.com>
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On Mon, Nov 15, 2021 at 02:17:15PM -0600, Michael Roth wrote:
> but in order for that to happen soon enough to make use of the CPUID
> table for all CPUID intructions, it needs to be moved to just after the first
> #VC handler is setup (where snp_cpuid_init() used to be in v6).

So, it needs to happen after the initial IDT is loaded on the BSP in
startup_64_setup_env().

So why don't you call sme_enable() right after the
startup_64_setup_env() call and add a comment above it to explain why
this call needs to happen there?

Instead of sticking that call in startup_64_setup_env() where it doesn't
belong conceptually - enabling SME doesn't really have anything to do
with setting up early environment...

Hmm.

-- 
Regards/Gruss,
    Boris.

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