Currently, monitoring QEMU virtual machines with standard Unix
sysadmin tools is harder than it has to be. The QEMU command line is
often miles long and mostly redundant, it's hard to tell which process
is which.
This patch reorders the QEMU -name argument to be the first, so it's
immediately visible in "ps x", htop and "atop -c" output.
In the past, generic SCSI commands issued from a guest to a virtio
disk were always passed through to the underlying disk by qemu, and
the kernel would also pass them on.
As a result of CVE-2011-4127 (see:
http://seclists.org/oss-sec/2011/q4/536), qemu now honors its
scsi=on|off device option for virtio-blk-pci (which enables/disables
passthrough of generic SCSI commands), and the kernel will only allow
the commands for physical devices (not for partitions or logical
volumes). The default behavior of qemu is still to allow sending
generic SCSI commands to physical disks that are presented to a guest
as virtio-blk-pci devices, but libvirt prefers to disable those
commands in the standard virtio block devices, enabling it only when
specifically requested (hopefully indicating that the requester
understands what they're asking for). For this purpose, a new libvirt
disk device type (device='lun') has been created.
device='lun' is identical to the default device='disk', except that:
1) It is only allowed if bus='virtio', type='block', and the qemu
version is "new enough" to support it ("new enough" == qemu 0.11 or
better), otherwise the domain will fail to start and a
CONFIG_UNSUPPORTED error will be logged).
2) The option "scsi=on" will be added to the -device arg to allow
SG_IO commands (if device !='lun', "scsi=off" will be added to the
-device arg so that SG_IO commands are specifically forbidden).
Guests which continue to use disk device='disk' (the default) will no
longer be able to use SG_IO commands on the disk; those that have
their disk device changed to device='lun' will still be able to use SG_IO
commands.
*docs/formatdomain.html.in - document the new device attribute value.
*docs/schemas/domaincommon.rng - allow it in the RNG
*tests/* - update the args of several existing tests to add scsi=off, and
add one new test that will test scsi=on.
*src/conf/domain_conf.c - update domain XML parser and formatter
*src/qemu/qemu_(command|driver|hotplug).c - treat
VIR_DOMAIN_DISK_DEVICE_LUN *almost* identically to
VIR_DOMAIN_DISK_DEVICE_DISK, except as indicated above.
Note that no support for this new device value was added to any
hypervisor drivers other than qemu, because it's unclear what it might
mean (if anything) to those drivers.
One of the xml tests in the test suite was created using a
now-deprecated qemu machine type ("fedora-13", which was only ever
valid for Fedora builds of qemu). Although strictly speaking it's not
necessary to replace it with an actual supported qemu machine type
(since the xml in question is never actually sent to qemu), this patch
changes it to the actually-supported "pc-0.13" just for general
tidiness. (Also, on some Fedora builds which contain a special patch
to rid the world of "fedora-13", having it mentioned in the test suite
will cause make check to fail.)
This patch teaches testutil how to read multi-line input files with
backspace-newline line continuation markers.
The patch also breaks up all the single-line arguments test input files into
multi-line files with lines shorter than 80 characters.
We already use the '-nodefaults' command line arg with QEMU to stop
it adding any default devices to guests. Unfortunately, QEMU will
load global config files from /etc/qemu that may also add default
devices. These aren't blocked by '-nodefaults', so we need to also
add the '-nodefconfig' arg to prevent that.
Unfortunately these global config files are also used to define
custom CPU models. So in blocking global hardware device addition
we also block definitions of new CPU models. Libvirt doesn't know
about these custom CPU models though, so it would never make use
of them anyway. Thus blocking them via -nodefconfig isn't a show
stopping problem. We would need to expand libvirt's own CPU model
XML database to support these instead.
* src/qemu/qemu_conf.c: Add '-nodefconfig' if available
* tests/qemuxml2argvdata/: Add '-nodefconfig' to all data files which
have '-nodefaults' present
* virStorageEncryptionFormat is called from both
virDomainDiskDefFormat and virStorageVolTargetDefFormat. The proper
indentation in the generated XML depends on the caller. My earlier
patch to fix the incorrect indentation for the domain XML broke the
indentation for the storage XML. This patch adopts Laine's
suggestion of requring the caller of virStorageEncryptionFormat to
provide an unsigned int with the number of spaces the output should
be indented. The patch modifies both callers to provide the
additional argument.
* Add a regression test for the domain XML
* src/conf/domain_conf.c src/conf/storage_conf.c
src/conf/storage_encryption_conf.c src/conf/storage_encryption_conf.h:
change the indentation code
* tests/qemuxml2xmltest.c
tests/qemuxml2argvdata/qemuxml2argv-encrypted-disk.args
tests/qemuxml2argvdata/qemuxml2argv-encrypted-disk.xml: add a regression test
