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Date:   Thu, 30 Nov 2023 10:07:24 -0600
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Subject: Re: [PATCH] x86/sev: Fix kernel crash due to late update to read-only
 ghcb_version
Content-Language: en-US
To:     Ingo Molnar <mingo@kernel.org>,
        Ashwin Dayanand Kamat <kashwindayan@vmware.com>
Cc:     linux-kernel@vger.kernel.org, bp@alien8.de, brijesh.singh@amd.com,
        tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com,
        x86@kernel.org, hpa@zytor.com, jroedel@suse.de,
        stable@vger.kernel.org, ganb@vmware.com, tkundu@vmware.com,
        vsirnapalli@vmware.com, akaher@vmware.com, amakhalov@vmware.com,
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References: <1701254429-18250-1-git-send-email-kashwindayan@vmware.com>
 <ZWhWI2GvfleyGKsa@gmail.com>
From:   Tom Lendacky <thomas.lendacky@amd.com>
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On 11/30/23 03:30, Ingo Molnar wrote:
> 
> * Ashwin Dayanand Kamat <kashwindayan@vmware.com> wrote:
> 
>> From: Ashwin Dayanand Kamat <ashwin.kamat@broadcom.com>
>>
>> kernel crash was observed because of page fault, while running
>> cpuhotplug ltp testcases on SEV-ES enabled systems. The crash was
>> observed during hotplug after the CPU was offlined and the process
>> was migrated to different cpu. setup_ghcb() is called again which
>> tries to update ghcb_version in sev_es_negotiate_protocol(). Ideally this
>> is a read_only variable which is initialised during booting.
>> This results in pagefault.
> 
> Applied to tip:x86/urgent, thanks.
> 
> Tom: I've added your Suggested-by and Acked-by, which appeared to be the
> case given the v1 discussion, let me know if that's not accurate.

All good.

Thanks,
Tom

> 
> I've also tidied up the changelog - final version attached below.
> 
> Thanks,
> 
> 	Ingo
>