[libvirt] [PATCH 1/3] firmware: include arch and features in firmware file list

[Daniel P. Berrange]

On Wed, Oct 19, 2016 at 02:13:52PM +0100, Richard W.M. Jones wrote:
> On Wed, Oct 19, 2016 at 01:18:07PM +0100, Daniel P. Berrange wrote:
> > On Wed, Oct 19, 2016 at 01:07:25PM +0100, Richard W.M. Jones wrote:
> > > Unfortunately it's a case of so near and yet so far.  You're proposing
> > > this essentially static and non-secret data be stored in
> > > /etc/libvirt/qemu.conf, which is not readable as non-root.  virt-v2v
> > > (which can run as non-root) would still need to store a duplicate copy
> > > of the data.
> > 
> > What does v2v need the mapping data for ?  Any use case needs to be
> > addressed via the APIs, not having apps poke at libvirt private
> > config files.
> 
> Well the use is fairly narrow (and not present in RHEL).  If you use
> `-o qemu' mode, then virt-v2v will write a shell script that invokes
> qemu directly.  To do this for UEFI guests it needs to know the right
> firmware paths to use.

Oh, but that's outside scope of libvirt then - we're not looking to
expose APIs to help people run QEMU directly.

> There's also the issue of writing guests out to old versions of
> libvirt, but I'm not too worried about that since we could make the
> switch after we are sure the minimum version of libvirt supports
> <firmware/> everywhere.
> 
> Libguestfs itself also uses UEFI paths on aarch64 when backend = direct
> to run the appliance.

Ok, but that's outside scope of libvirt again.

> We could query the data through an API, I suppose, although that
> assumes libvirt is present.  Could this information be stored
> somewhere outside libvirt?  It's useful for people running qemu
> directly.

With other BIOS files, QEMU has a location it expects them to be at,
but this isn't applicable to UEFI since none of the QEMU machine types
default to using UEFI. If some machine types did start defaulting to
UEFI, then QEMU would have to define this in some manner, as it does
for other BIOS. There's the slight extra complication in that there
are multiple possible BIOS files for UEFI depending on featureset
you want to use :-(

Regards,
Daniel
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