Re: [PATCH v11 18/20] x86: Handle TDX erratum to reset TDX private memory during kexec() and reboot

[kirill.shutemov@xxxxxxxxxxxxxxx]

On Wed, Jun 14, 2023 at 09:33:45AM +0000, Huang, Kai wrote:
> On Mon, 2023-06-05 at 02:27 +1200, Kai Huang wrote:
> > --- a/arch/x86/kernel/reboot.c
> > +++ b/arch/x86/kernel/reboot.c
> > @@ -720,6 +720,7 @@ void native_machine_shutdown(void)
> >  
> >  #ifdef CONFIG_X86_64
> >  	x86_platform.iommu_shutdown();
> > +	x86_platform.memory_shutdown();
> >  #endif
> >  }
> 
> Hi Kirill/Dave,
> 
> I missed that this solution doesn't reset TDX private for emergency restart or
> when reboot_force is set, because machine_shutdown() isn't called for them.
> 
> Is it acceptable?  Or should we handle them too?

Force reboot is not used in kexec path, right? And the platform has to
handle erratum in BIOS to reset memory status on reboot anyway.

I think we should be fine. But it worth mentioning it in the commit
message.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov