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From:   Thomas Gleixner <tglx@linutronix.de>
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To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        mingo@redhat.com, bp@alien8.de, dave.hansen@intel.com,
        luto@kernel.org, peterz@infradead.org
Cc:     sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com,
        ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com,
        hpa@zytor.com, jgross@suse.com, jmattson@google.com,
        joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org,
        pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com,
        tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com,
        thomas.lendacky@amd.com, brijesh.singh@amd.com, x86@kernel.org,
        linux-kernel@vger.kernel.org,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCHv6 23/30] x86/boot: Avoid #VE during boot for TDX platforms
In-Reply-To: <20220316020856.24435-24-kirill.shutemov@linux.intel.com>
References: <20220316020856.24435-1-kirill.shutemov@linux.intel.com>
 <20220316020856.24435-24-kirill.shutemov@linux.intel.com>
Date:   Thu, 17 Mar 2022 13:48:01 +0100
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On Wed, Mar 16 2022 at 05:08, Kirill A. Shutemov wrote:
> This theoretically makes the guest boot more fragile. If, for instance,
> EFER was set up incorrectly and a WRMSR was performed, it will trigger
> early exception panic or a triple fault, if it's before early
> exceptions are set up. However, this is likely to trip up the guest
> BIOS long before control reaches the kernel. In any case, these kinds
> of problems are unlikely to occur in production environments, and
> developers have good debug tools to fix them quickly.
>
> Change the common boot code to work on TDX and non-TDX systems.
> This should have no functional effect on non-TDX systems.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Reviewed-by: Andi Kleen <ak@linux.intel.com>
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>