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>
Most of the differences, such as those in the domain name or
amount of memory, are fairly harmless, but they still make it
more cumbersome than necessary to directly compare different
input (and output) files.
More importantly, the use of unversioned machine types in some
of the test cases results in the descriptor-based autoselection
logic being effectively skipped, because the compatible machine
types as listed in them are only the versioned variants.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The iTCO watchdog is part of the q35 machine type since its inception,
we just did not add it implicitly.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2137346
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Normally when an UEFI firmware is marked as read-only, an associated
NVRAM file will be created. Some builds of UEFI firmware, however, wish
to remain stateless and so will be read-only, but never have any NVRAM
file. To represent this concept a 'stateless' tristate bool attribute
is introduced on the <loader/> element.
There are rather a large number of permutations to consider.
With default firmware selection
* <os/>
=> Historic default, no change
* <os>
<loader stateless='yes'/>
</os>
=> Explicit version of historic default, no change
* <os>
<loader stateless='no'/>
</os>
=> Invalid, bios is always stateless
With manual legacy BIOS selection
* <os>
<loader>/path/to/seabios</loader>
...
</os>
=> Historic default, no change
* <os>
<loader stateless='yes'>/path/to/seabios</loader>
...
</os>
=> Explicit version of historic default, no change
* <os>
<loader stateless='no'>/path/to/seabios</loader>
...
</os>
=> Invalid, bios is always stateless
With manual UEFI selection
* <os>
<loader type='pflash'>/path/to/edk2</loader>
...
</os>
=> Historic default, no change
* <os>
<loader type='pflash' stateless='yes'>/path/to/edk2</loader>
...
</os>
=> Skip auto-filling NVRAM / template
* <os>
<loader type='pflash' stateless='no'>/path/to/edk2</loader>
...
</os>
=> Explicit version of historic default, no change
With automatic firmware selection
* <os firmware='bios'/>
=> Historic default, no change
* <os firmware='bios'>
<loader stateless='yes'/>
</os>
=> Explicit version of historic default, no change
* <os firmware='bios'>
<loader stateless='no'/>
</os>
=> Invalid, bios is always stateless
* <os firmware='uefi'/>
=> Historic default, no change
* <os firmware='uefi'>
<loader stateless='yes'/>
</os>
=> Skip auto-filling NVRAM / template
* <os firmware='uefi'>
<loader stateless='no'/>
</os>
=> Explicit version of historic default, no change
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
