Re: [PATCH v7 11/20] x86/virt/tdx: Add placeholder to construct TDMRs to cover all TDX memory regions

[Huang, Kai]

On Thu, 2022-12-08 at 06:58 -0800, Dave Hansen wrote:
> On 12/8/22 04:56, Huang, Kai wrote:
> > I haven't looked into the reason yet but I suspect the address isn't aligned (I
> > used __pa() to get the physical address).  I'll take a look and report back.
> > 
> > In the meantime, do you have any comments?  Should I still pursue to keep them
> > as local variable on the stack?
> 
> Yes, you should investigate the reason for the failure and try to
> understand both the success and the failure cases.

Hi Dave,

Learned something new from Kirill today.

The reason is not the alignment, but it's wrong to use __pa() to get the
physical address of function local variable on the stack.  It is because Kirill
told me kernel stack can now be allocated via vmalloc(), so use __pa() won't
work.

I changed to use slow_virt_to_phys() and tried in my testing and it now works.

So I'll change to use slow_virt_to_phys() for the next version.  We can take a
look at the new version to see if that is what you wanted.

Thanks for your time.