Re: [PATCH V4 2/2] OvmfPkg: Update CcProbeLib to DxeCcProbeLib

["Min Xu" <min.m.xu@intel.com>]

On August 29, 2022 9:37 PM, Tom Lendacky wrote:
> On 8/26/22 18:07, Min Xu wrote:
> > From: Min M Xu <min.m.xu@intel.com>
> >
> > BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3974
> >
> > To gurantee the GuestType is cached, we read the value in both
> 
> s/gurantee/guarantee/
Thanks for reminder. It will be fixed in the next version.
> 
> > constructor and CcProbe. Because in some corner case, the constructor
> > may be called after CcProbe. For example in
> > MdeModulePkg/Core/Dxe/DxeMain, BaseDebugLibSerialPortConstructor is
> > called before DxeCcProbeLibConstructor. While CcProbe () is called in
> > BaseDebugLibSerialPortConstructor.
> 
> Is there a way to put some kind of ordering in place so that CcProbe's
> constructor is called before BaseDebugLibSerialPortConstructor?
Even there is a way to make the CcProbe's constructor be called before BaseDebugLibSerialPortConstructor, we cannot guarantee it will not be broken in the future. So I think it's safer to read the ovmf work area in both constructor and CcProbe.
> 
> >
> > The reason why we probe CC guest type in 2 different ways is the
> > global varialbe. Global variable cannot be used in SEC/PEI and CcProbe
> > is called
> 
> s/varialbe/variable/
Thanks for reminder. It will be fixed in the next version.

Thanks
Min