Re: [edk2-devel] [PATCH 0/3] CloudHv: Rely on PVH boot specification

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

If you want to support PVH-only, that means you *defeature* the CloudHv in *edk2-stable202202* tag according to https://github.com/tianocore/tianocore.github.io/wiki/EDK-II-Release-Planning.
I hope that is stated clearly, with justification why we choose PVH-only. Something like: "In edk2-stable202202, CloudHv supported xxx. In edk2-stable202205 or future, CloudHv for non-TDX will only support PVH, because xxxxxx. The CloudFv for TDX will continue support xxx." An ASCII table is preferred to clarify the combination.

If possible, please create a similar README under https://github.com/tianocore/edk2/tree/master/OvmfPkg/CloudHv to record such info. (configuration, feature, supported v.s. unsupported, URL link, how to build, how to launch, etc)


FYI: The readme in Microvm is a good example - https://github.com/tianocore/edk2/blob/master/OvmfPkg/Microvm/README.

Thank you
Yao Jiewen

> -----Original Message-----
> From: Boeuf, Sebastien <sebastien.boeuf@intel.com>
> Sent: Wednesday, February 23, 2022 8:20 PM
> To: kraxel@redhat.com; devel@edk2.groups.io
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Justen, Jordan L
> <jordan.l.justen@intel.com>
> Subject: Re: [edk2-devel] [PATCH 0/3] CloudHv: Rely on PVH boot specification
> 
> On Wed, 2022-02-23 at 13:02 +0100, kraxel@redhat.com wrote:
> >   Hi,
> >
> > > Well that's a good question. If we expect the same target (CloudHv)
> > > to
> > > support both TDX and non-TDX, that means the generated TDVF will be
> > > a
> > > PVH ELF binary, which will require some special handling from Cloud
> > > Hypervisor.
> > > Having two separate targets would simplify things a lot. What's the
> > > plan for QEMU? Will the same OVMF target cover both use cases?
> >
> > Yes, there will be a single binary supporting both tdx and non-tdx,
> > some
> > configs add sev to the mix.  Doing the same for cloudhv shouldn't be
> > much
> > of a problem I think.
> >
> > In tdx mode the firmware uses the tdhob for memory detection, in non-
> > tdx
> > mode qemu fw_cfg is used instead.  The cloudhv build could switch
> > between tdhob and pvhinfo in a simliar way.
> 
> Sounds good :)
> 
> >
> > take care,
> >  Gerd
> >