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To: Anthony PERARD <anthony.perard@citrix.com>, marcandre.lureau@redhat.com
Cc: edk2-devel@lists.01.org, Jordan Justen <jordan.l.justen@intel.com>,
 Ard Biesheuvel <ard.biesheuvel@linaro.org>,
 Julien Grall <julien.grall@linaro.org>
References: <20181002121725.17178-1-marcandre.lureau@redhat.com>
 <20181002132725.GA1331@perard.uk.xensource.com>
From: Laszlo Ersek <lersek@redhat.com>
Message-ID: <28889e1a-e346-4c71-1afb-533466e09fc8@redhat.com>
Date: Tue, 2 Oct 2018 17:03:59 +0200
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 (mx1.redhat.com [10.5.110.27]); Tue, 02 Oct 2018 15:04:13 +0000 (UTC)
Subject: Re: [PATCH v3 1/1] OvmfPkg/PlatformPei: clear CPU caches
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On 10/02/18 15:27, Anthony PERARD wrote:
> On Tue, Oct 02, 2018 at 04:17:25PM +0400, marcandre.lureau@redhat.com wrote:
>> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>>
>> This is for conformance with the TCG "Platform Reset Attack Mitigation
>> Specification". Because clearing the CPU caches at boot doesn't impact
>> performance significantly, do it unconditionally, for simplicity's
>> sake.
>>
>> Flush the cache on all logical processors, thanks to
>> EFI_PEI_MP_SERVICES_PPI and CacheMaintenanceLib.
>>
>> Cc: Jordan Justen <jordan.l.justen@intel.com>
>> Cc: Laszlo Ersek <lersek@redhat.com>
>> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> Cc: Anthony Perard <anthony.perard@citrix.com>
>> Cc: Julien Grall <julien.grall@linaro.org>
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> That patch works for me on Xen. I can still boot guests with the patch
> applied, with either 1 or 4 vcpus assigned to the guest:
> 
> Tested-by: Anthony PERARD <anthony.perard@citrix.com>

Thanks a lot!
Laszlo