Re: [edk2-devel] [PATCH] UefiCpuPkg/MpInitLib: Skip reading PlatformId on AMD processors.

["Duran, Leo" <leo.duran@amd.com>]

> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Monday, April 20, 2020 5:41 AM
> To: Gary Lin <glin@suse.com>; devel@edk2.groups.io; Duran, Leo
> <leo.duran@amd.com>
> Cc: Eric Dong <eric.dong@intel.com>; Ray Ni <ray.ni@intel.com>
> Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg/MpInitLib: Skip reading
> PlatformId on AMD processors.
> 
> On 04/17/20 10:14, Gary Lin wrote:
> > On Sat, Feb 29, 2020 at 09:05:45AM -0600, Leo Duran wrote:
> >> REF:
> >>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbug
> >>
> zilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D2556&amp;data=02%7C01%7
> Cleo
> >>
> .duran%40amd.com%7C10bcdc9150b24c3c53c108d7e50ef6a9%7C3dd8961fe
> 4884e6
> >>
> 08e11a82d994e183d%7C0%7C0%7C637229724752057989&amp;sdata=fcn7
> g8Tpx97I
> >> U6FBPB%2BZ8wJFMtd9zhQzxJIhOct%2B1Vo%3D&amp;reserved=0
> >>
> >> This patch uses CPUID signature check to skip reading the PlatformId
> >> MSR, which is not implemented on AMD processors.
> >>
> >> The PlatformId is used for loading microcode patches, which is also
> >> not supported and AMD-based platforms. To mitigate the PlatformId
> >> dependency, PcdCpuMicrocodePatchAddress and
> >> PcdCpuMicrodePatchRegionSize must be set to 0 (default value), in order
> to bypass microcode loading code paths.
> >>
> > I got an error report about the executable bit of MpLib.h while
> > packaging ovmf. It turned out that this patch accidentally changed the
> > file mode. It would be nice if the mode can be corrected.
> 
> Thanks for the report. I've filed
> <https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbug
> zilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D2678&amp;data=02%7C01%7
> Cleo.duran%40amd.com%7C10bcdc9150b24c3c53c108d7e50ef6a9%7C3dd89
> 61fe4884e608e11a82d994e183d%7C0%7C0%7C637229724752057989&amp;
> sdata=wlBDe%2BOTRXpUyuCyJv5aJd1mH7NMbNkzZ%2B4obnhkfx0%3D&am
> p;reserved=0> and assigned it to Leo.
> 
> Leo, can you please submit the patch?
[Duran, Leo] 
Yes, I can do that... Unless the Maintainer prefers to take care of the file permission bits.

> 
> Thanks!
> Laszlo