Re: [PATCH 0/2] Put AP into safe hlt-loop code on S3 path

[Laszlo Ersek <lersek@redhat.com>]

On 11/10/16 07:07, Jeff Fan wrote:
> On S3 path, we will wake up APs to restore CPU context in PiSmmCpuDxeSmm
> driver. In case, one NMI or SMI happens, APs may exit from hlt state and
> execute the instruction after HLT instruction.
> 
> But APs are not running on safe code, it leads OVMF S3 boot unstable.
> 
> https://bugzilla.tianocore.org/show_bug.cgi?id=216
> 
> I tested real platform with 64bit DXE.
> 
> Jeff Fan (2):
>   UefiCpuPkg/PiSmmCpuDxeSmm: Put AP into safe hlt-loop code on S3 path
>   UefiCpuPkg/PiSmmCpuDxeSmm: Place AP to 32bit protected mode on S3 path
> 
>  UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c             | 31 ++++++++++++++
>  UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmFuncsArch.c | 25 ++++++++++++
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h    | 13 ++++++
>  UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c  | 59 +++++++++++++++++++++++++++
>  4 files changed, 128 insertions(+)
> 

Can we please append, to both commit messages:

Analyzed-by: Paolo Bonzini <pbonzini@redhat.com>

I think we should give credit to Paolo for his work in this thread.

I'll report back with test results (with my suggested rounding-down of
TopOfStack in patch #1).

Thanks
Laszlo