Even when the user is not taking advantage of firmware
autoselection and instead manually providing all the necessary
information, in most cases they're still going to use firmware
builds that are provided by the OS vendor, are installed in
standard paths and come with a corresponding firmware
descriptor.
Similarly, even when the user is not guiding the autoselection
process by specifying the desired status of certain features
and instead is relying on the system-level descriptor priority
being set up correctly, libvirt will still ultimately decide to
use a specific descriptor, which includes information about the
firmware's features.
In both these cases, take the additional information that were
obtained from the firmware descriptor and reflect them back into
the domain XML, where they can be conveniently inspected by the
user and management applications alike.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Now that we no longer reject configurations that include both
this information and explicit firmware details, as long of
course as everything is internally consistent, and that we've
ensured that we produce maximally compatible XML on migration,
we can stop stripping this information at the end of the
firmware selection process.
There are several advantages to keeping this information around:
* if the user wants to change the firmware configuration for
an existing VM, they can simply drop the <loader> and
<nvram> elements, tweak the firmware autoselection parameters
and let libvirt pick a firmware that matches on the new
requirements;
* management applications can inspect the XML and easily
figure out firmware-related information without having to
reverse-engineer them based on some opaque paths.
Overall, this change makes things more transparent and easier to
understand. The improvement is so significant that, in a
follow-up commit, we're going to ensure that this information is
available in even more cases.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Currently, firmware selection is performed as part of the
domain startup process. This mostly works fine, but there's a
significant downside to this approach: since the process is
affected by factors outside of libvirt's control, specifically
the contents of the various JSON firmware descriptors and
their names, it's pretty much impossible to guarantee that the
outcome is always going to be the same. It would only take an
edk2 update, or a change made by the local admin, to render a
domain unbootable or downgrade its boot security.
To avoid this, move firmware selection to the postparse phase.
This way it will only be performed once, when the domain is
first defined; subsequent boots will not need to go through
the process again, as all the paths that were picked during
firmware selection are recorded in the domain XML.
Care is taken to ensure that existing domains are handled
correctly, even if their firmware configuration can't be
successfully resolved. Failure to complete the firmware
selection process is only considered fatal when defining a
new domain; in all other cases the error will be reported
during startup, as is already the case today.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
These cover scenarios such as using the new, more verbose
format of the <nvram> element to point to a local path, mixing
firmware autoselection with non-local NVRAM files, and
explicitly disabling SMM when using firmware autoselection.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
