If you've ever tried running a huge page backed guest under
different user than in qemu.conf, you probably failed. Problem is
even though we have corresponding APIs in the security drivers,
there's no implementation and thus we don't relabel the huge page
path. But even if we did, so far all of the domains share the
same path:
/hugepageMount/libvirt/qemu
Our only option there would be to set 0777 mode on the qemu dir
which is totally unsafe. Therefore, we can create dir on
per-domain basis, i.e.:
/hugepageMount/libvirt/qemu/domainName
and chown domainName dir to the user that domain is configured to
run under.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
As with other devices assign the slot number right away when adding the
device. This will make the slot numbers static as we do with other
addressing elements and it will ultimately simplify allocation of the
alias in a static way which does not break with qemu.
Per-domain directories were introduced in order to be able to
completely separate security labels for each domain (commit
f1f68ca334). However when the domain
name is long (let's say a ridiculous 110 characters), we cannot
connect to the monitor socket because on length of UNIX socket address
is limited. In order to get around this, let's shorten it in similar
fashion and in order to avoid conflicts, throw in an ID there as well.
Also save that into the status XML and load the old status XMLs
properly (to clean up after older domains). That way we can change it
in the future.
The shortening can be seen in qemuxml2argv tests, for example in the
hugepages-pages2 case.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Just recently, qemu forbade specifying format for sourceless
disks (qemu commit 39c4ae941ed992a3bb5). It kind of makes sense.
If there's no file to open, why specify its format. Anyway, I
have a domain like this:
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<target dev='hda' bus='ide'/>
<readonly/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
and obviously I am unable to start it. Therefore, a fix on our
side is needed too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
As of QEMU 0.10.0 the -drive format= parameter was added,
so the QEMU driver can assume it is always available.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Back in
commit bd6c46fa0c
Author: Juerg Haefliger <juerg.haefliger@hp.com>
Date: Mon Jan 31 06:42:57 2011 -0500
tests: handle backspace-newline pairs in test input files
all the test argv files were line wrapped so that the args
were less than 80 characters.
The way the line wrapping was done turns out to be quite
undesirable, because it often leaves multiple parameters
on the same line. If we later need to add or remove
individual parameters, then it leaves us having to redo
line wrapping.
This commit changes the line wrapping so that every
single "-param value" is one its own new line. If the
"value" is still too long, then we break on ',' or ':'
or ' ' as needed.
This means that when we come to add / remove parameters
from the test files line, the patch diffs will only
ever show a single line added/removed which will greatly
simplify review work.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
We are using memory-backing-file even when it's not needed, for example
if user requests hugepages for memory backing, but does not specify any
pagesize or memory node pinning. This causes migrations to fail when
migrating from older libvirt that did not do this. So similarly to
commit 7832fac847 which does it for
memory-backend-ram, this commit makes is more generic and
backend-agnostic, so the backend is not used if there is no specific
pagesize of hugepages requested, no nodeset the memory node should be
bound to, no memory access change required, and so on.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1266856
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Proper Haswell CPU model handling is tested in several
qemuxml2argv-cpu-* which are run in a special environment. Let's remove
the CPU model from other tests to make them less fragile.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
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>
https://bugzilla.redhat.com/show_bug.cgi?id=1196644
This function constructs the backend (host facing) part of the
memory device. At the beginning, the configured hugepages are
searched to find the best match for given guest NUMA node.
Configured hugepages can have a @nodeset attribute to specify on
which guest NUMA nodes should be the hugepages backing used.
There is, however, one 'corner case'. Users may just tell 'use
hugepages to back all the nodes'. In other words:
<memoryBacking>
<hugepages/>
</memoryBacking>
<cpu>
<numa>
<cell id='0' cpus='0-1' memory='1024000' unit='KiB'/>
</numa>
</cpu>
Our code fails in this case. Well, since there's no @nodeset (nor
any <page/> child element to <hugepages/>) we fail to lookup the
default hugepage size to use.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
