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>
My original implementation was based on a qemu version that still did
not have all the checks in place. Using sizes that would align to odd
megabyte increments will produce the following error:
qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,id=dimm0: backend memory size must be multiple of 0x200000
qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,id=dimm0: Device 'pc-dimm' could not be initialized
Introduce an alignment retrieval function for memory devices and use it
to align the devices separately and modify a test case to verify it.
So far the argument has not much meaning and was practically ignored.
This is not good since when doing memory hotplug, the size of desired
hugepage backing is passed in that argument. Taking closer look at the
tests I'm fixing reveals the bug. For instance, while the following is
in the test:
<memory model='dimm'>
<source>
<nodemask>1-3</nodemask>
<pagesize unit='KiB'>4096</pagesize>
</source>
<target>
<size unit='KiB'>524287</size>
<node>0</node>
</target>
<address type='dimm' slot='0' base='0x100000000'/>
</memory>
the generated commandline corresponding to this XML was:
-object memory-backend-ram,id=memdimm0,size=536870912,\
host-nodes=1-3,policy=bind
Have you noticed? Yes, memory-backend-ram! Nothing can be further away
from the right answer. The hugepage backing is requested in the XML
and we happily ignore it. This is just not right. It's
memory-backend-file which should have been used:
-object memory-backend-file,id=memdimm0,prealloc=yes,\
mem-path=/dev/hugepages4M/libvirt/qemu,size=536870912,\
host-nodes=1-3,policy=bind
The problem is, that @pagesize passed to qemuBuildMemoryBackendStr
(where this part of commandline is built) was ignored. The hugepage to
back memory was searched only and only by NUMA nodes pinning. This
works only for regular guest NUMA nodes.
Then, I'm changing the hugepages size in the test XMLs too. This is
simply because in the test suite we create dummy mount points just for
2M and 1G hugepages. And in the test 4M was requested. I'm sticking to
2M, but 1G should just work too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
After parsing the memory device XML the function would not restore the
XML parser context causing invalid XPath starting point for the rest of
the elements. This is a regression since 3e4230d2.
The test case addition uses the <idmap> element that is currently unused
by qemu, but parsed after the memory device definition and formatted
always.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1223631
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
This patch adds code that parses and formats configuration for memory
devices.
A simple configuration would be:
<memory model='dimm'>
<target>
<size unit='KiB'>524287</size>
<node>0</node>
</target>
</memory>
A complete configuration of a memory device:
<memory model='dimm'>
<source>
<pagesize unit='KiB'>4096</pagesize>
<nodemask>1-3</nodemask>
</source>
<target>
<size unit='KiB'>524287</size>
<node>1</node>
</target>
</memory>
This patch preemptively forbids use of the <memory> device in individual
drivers so the users are warned right away that the device is not
supported.
