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Subject: Re: [PATCH] x86/xen: disable Firmware First mode for correctable
 memory errors
To:     boris.ostrovsky@oracle.com, Juergen Gross <jgross@suse.com>,
        x86@kernel.org, linux-kernel@vger.kernel.org
Cc:     xen-devel@lists.xenproject.org,
        Stefano Stabellini <sstabellini@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, stable@vger.kernel.org
References: <20200925101148.21012-1-jgross@suse.com>
 <171970df-5f6e-5a2b-e784-e62d300a005b@oracle.com>
From:   Jan Beulich <jbeulich@suse.com>
Message-ID: <c017f364-e34c-092c-18ca-0ab9a2d75f59@suse.com>
Date:   Fri, 25 Sep 2020 16:00:53 +0200
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On 25.09.2020 15:45, boris.ostrovsky@oracle.com wrote:
> On 9/25/20 6:11 AM, Juergen Gross wrote:
>> @@ -1296,6 +1296,14 @@ asmlinkage __visible void __init xen_start_kernel(void)
>>  
>>  	xen_smp_init();
>>  
>> +#ifdef CONFIG_ACPI
>> +	/*
>> +	 * Disable selecting "Firmware First mode" for correctable memory
>> +	 * errors, as this is the duty of the hypervisor to decide.
>> +	 */
>> +	acpi_disable_cmcff = 1;
>> +#endif
> 
> 
> Not that it matters greatly but should this go under if (xen_initial_domain())
> clause a bit further down?

Yes - DomU-s are supposed to be in charge of their (virtual) firmware,
no matter that right now APEI for guests is completely out of sight as
far as I'm aware.

Jan