While reviewing a patch from Andrea that modified this test case, I
realized that although it was "properly failing" (it's a negative
test), that it was failing for the wrong reason (the MULTIFUNCTION cap
wasn't set in the test case, so it was saying that multifunction=on
wasn't supported by the QEMU binary; instead it should have been
complaining that it had run out of PCI slots of the appropriate type
and couldn't automatically add any more).
This improper failure had started when I added the patch to
automatically aggregate pcie-root-ports onto multiple functions of
each pcie-root slot, but I hadn't noticed it because the test still
failed.
This patch corrects the test case to 1) set the MULTIFUNCTION flag in
the caps, and 2) attempt to add 241 pcie-root-ports to a domain. Since
there are 30 slots available on a pcie-root (slot 0 is reserved, and
slot 31 is used by the integrated SATA controller), and a
pcie-root-port can only be placed on a function of a slot on
pcie-root, the maximum number of pcie-root-ports in any domain is 240.
Up until a while ago, libvirt would automatically add a legacy
PCI controllers combo (dmi-to-pci-bridge + pci-bridge) to any
PCIe machine type (x86_64/q35 and aarch64/virt).
As a result, a number of input and output files in the test
suite ended up containing the legacy PCI controllers, even
though they are not needed or in any way relevant to the
feature being tested.
Get rid of most of the occurrences. Most of the time, this
just means removing the controllers from the input file and
regenerating the output files; in a few instances, some
minor tweaking is performed on the input file, most notably
removing the memory balloon: as memory balloon support was
not the scope of the test being changed, there is no loss
of test coverage from doing so.
Several occurrences of the legacy PCI controllers remain in
the test suite, both because removing their usage would have
required even more tweaking, and because we still want to
have coverage of this perfectly valid combination.
The current code was a little bit odd. At first we've removed all
possible implicit input devices from domain definition to add them later
back if there was any graphics device defined while parsing XML
description. That's not all, while formating domain definition to XML
description we at first ignore any input devices with bus different to
USB and VIRTIO and few lines later we add implicit input devices to XML.
This seems to me as a lot of code for nothing. This patch may look
to be more complicated than original approach, but this is a preferred
way to modify/add driver specific stuff only in those drivers and not
deal with them in common parsing/formating functions.
The update is to add those implicit input devices into config XML to
follow the real HW configuration visible by guest OS.
There was also inconsistence between our behavior and QEMU's in the way,
that in QEMU there is no way how to disable those implicit input devices
for x86 architecture and they are available always, even without graphics
device. This applies also to XEN hypervisor. VZ driver already does its
part by putting correct implicit devices into live XML.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
This is backed by the qemu device ioh3420.
chassis and port from the <target> subelement are used to store/set the
respective qemu device options for the ioh3420. Currently, chassis is
set to be the index of the controller, and port is set to
"(slot << 3) + function" (per suggestion from Alex Williamson).
