回复: [edk2-devel] [PATCH] OvmfPkg: TdxDxe: Fix AsmRelocateApMailBoxLoop

["gaoliming" <gaoliming@byosoft.com.cn>]

Min, Isaku, Jiewen:
  Is this patch required to catch edk2 202205 stable tag?

Thanks
Liming
> -----邮件原件-----
> 发件人: devel@edk2.groups.io <devel@edk2.groups.io> 代表 Min Xu
> 发送时间: 2022年5月24日 17:14
> 收件人: Yamahata, Isaku <isaku.yamahata@intel.com>;
> devel@edk2.groups.io
> 主题: Re: [edk2-devel] [PATCH] OvmfPkg: TdxDxe: Fix
> AsmRelocateApMailBoxLoop
> 
> On May 24, 2022 3:54 PM, Yamahata, Isaku wrote:
> >
> > In TDX, Application Processor busy-loops on Mailbox for OS to issue
> > MpProtectedModeWakeupCommandWakeup command to UEFI.  As the
> AP
> > acking to it, it clears the command member according to ACPI spec 6.4,
> > 5.2.12.19 Multiprocessor Wakeup Structure: "The application processor
> > need clear the command to Noop(0) as the acknowledgement that the
> > command is received."
> > However, AsmRelocateApMailBoxLoop wrongly clears WakeupVector.
> > Correctly clear command instead of WakeupVector.
> >
> > Without this patch, TD guest kernel fails to boot APs.
> >
> > Fixes: fae5c1464d ("OvmfPkg: Add TdxDxe driver")
> > Cc: Min Xu <min.m.xu@intel.com>
> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> > ---
> >  OvmfPkg/TdxDxe/X64/ApRunLoop.nasm | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
> > b/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
> > index 49bd04415c..a859375fb8 100644
> > --- a/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
> > +++ b/OvmfPkg/TdxDxe/X64/ApRunLoop.nasm
> > @@ -69,7 +69,7 @@ MailBoxWakeUp:
> >      mov        rax, [rbx + WakeupVectorOffset]     ; OS sends a
> wakeup command
> > for a given APIC ID, firmware is supposed to reset     ; the command
field
> back
> > to zero as acknowledgement.-    mov        qword [rbx +
> WakeupVectorOffset],
> > 0+    mov        qword [rbx + CommandOffset], 0     jmp
> rax MailBoxSleep:
> > jmp       $--
> > 2.25.1
> 
> Thanks Isaku.
> Reviewed-by: Min Xu <min.m.xu@intel.com>
> 
> 
> 
> 
>