Re: [RFC PATCH v3 17/36] pflash_cfi01/tdx: Introduce ram_mode of pflash for TDVF

[Gerd Hoffmann]

  Hi,

> > If you don't need a pflash device, don't use it: simply map your nvram
> > region as ram in your machine. No need to clutter the pflash model like
> > that.

Using the pflash device for something which isn't actually flash looks a
bit silly indeed.

> 
> I know it's dirty to hack the pflash device. The purpose is to make the user
> interface unchanged that people can still use
> 
>       -drive if=pflash,format=raw,unit=0,file=/path/to/OVMF_CODE.fd
>         -drive if=pflash,format=raw,unit=1,file=/path/to/OVMF_VARS.fd
> 
> to create TD guest.

Well, if persistent vars are not supported anyway there is little reason
to split the firmware into CODE and VARS files.  You can use just use
OVMF.fd with a single pflash device.  libvirt recently got support for
that.

Just using -bios OVMF.fd might work too.  Daniel tried that recently for
sev, but ran into problems with wiring up ovmf metadata parsing for
-bios.  Don't remember the details though.

take care,
  Gerd