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

["Yao, Jiewen" <jiewen.yao@intel.com>]

Agree to merge to stable tag. Thanks for the reminder.

Reviewed-by: Jiewen Yao@intel.com

> -----Original Message-----
> From: gaoliming <gaoliming@byosoft.com.cn>
> Sent: Wednesday, May 25, 2022 10:40 AM
> To: devel@edk2.groups.io; Xu, Min M <min.m.xu@intel.com>; Yamahata, Isaku
> <isaku.yamahata@intel.com>
> Cc: Yao, Jiewen <jiewen.yao@intel.com>
> Subject: 回复: [edk2-devel] [PATCH] OvmfPkg: TdxDxe: Fix
> AsmRelocateApMailBoxLoop
> 
> 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>
> >
> >
> >
> > 
> >
> 
>