Re: [PATCH v7 09/20] x86/virt/tdx: Get information about TDX module and TDX-capable memory

[Huang, Kai]

On Fri, 2022-12-02 at 09:25 -0800, Dave Hansen wrote:
> On 12/2/22 03:19, Huang, Kai wrote:
> > Probably I forgot to mention the "r9" in practice always returns 32, so there
> > will be empty CMRs at the tail of the cmr_array[].
> 
> Right, so the r9 value is basically useless.  I bet the code gets
> simpler if you just ignore it.
> 
> > > But we can also do nothing here, but just skip empty CMRs when comparing the
> > > memory region to it (in next patch).
> > > 
> > > Or, we don't even need to explicitly check memory region against CMRs. If the
> > > memory regions that we provided in the TDMR doesn't fall into CMR, then
> > > TDH.SYS.CONFIG will fail. We can just depend on the SEAMCALL to do that.
> > 
> > Sorry to ping, but do you have any comments here?
> > 
> > How about we just don't do any check of TDX memory regions against CMRs, but
> > just let the TDH.SYS.CONFIG SEAMCALL to determine?
> 
> Right, if we screw it up TDH.SYS.CONFIG SEAMCALL will fail.  We don't
> need to add more code to detect that failure ourselves.  TDX is screwed
> either way.

Will do.  Thanks.