Thanks to the complex capability caching code virQEMUCapsProbeQMP was
never called when we were starting a new qemu VM. On the other hand,
when we are reconnecting to the qemu process we reload the capability
list from the status XML file. This means that the flag preventing the
function being called was not set and thus we partially reprobed some of
the capabilities.
The recent addition of CPU hotplug clears the
QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS if the machine does not support it.
The partial re-probe on reconnect results into attempting to call the
unsupported command and then killing the VM.
Remove the partial reprobe and depend on the stored capabilities. If it
will be necessary to reprobe the capabilities in the future, we should
do a full reprobe rather than this partial one.
QEMU 2.8.0 adds support for unavailable-features in
query-cpu-definitions reply. The unavailable-features array lists CPU
features which prevent a corresponding CPU model from being usable on
current host. It can only be used when all the unavailable features are
disabled. Empty array means the CPU model can be used without
modifications.
We can use unavailable-features for providing CPU model usability info
in domain capabilities XML:
<domainCapabilities>
...
<cpu>
<mode name='host-passthrough' supported='yes'/>
<mode name='host-model' supported='yes'>
<model fallback='allow'>Skylake-Client</model>
...
</mode>
<mode name='custom' supported='yes'>
<model usable='yes'>qemu64</model>
<model usable='yes'>qemu32</model>
<model usable='no'>phenom</model>
<model usable='yes'>pentium3</model>
<model usable='yes'>pentium2</model>
<model usable='yes'>pentium</model>
<model usable='yes'>n270</model>
<model usable='yes'>kvm64</model>
<model usable='yes'>kvm32</model>
<model usable='yes'>coreduo</model>
<model usable='yes'>core2duo</model>
<model usable='no'>athlon</model>
<model usable='yes'>Westmere</model>
<model usable='yes'>Skylake-Client</model>
...
</mode>
</cpu>
...
</domainCapabilities>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
"host" CPU model is supported by a special host-passthrough CPU mode and
users is not allowed to specify this model directly with custom mode.
Thus we should not advertise "host" CPU model in domain capabilities.
This worked well on architectures for which libvirt provides a list of
supported CPU models in cpu_map.xml (since "host" is not in the list).
But we need to explicitly filter "host" model out for all other
architectures.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
CPU models (and especially some additional details which we will start
probing for later) differ depending on the accelerator. Thus we need to
call query-cpu-definitions in both KVM and TCG mode to get all data we
want.
Tests in tests/domaincapstest.c are temporarily switched to TCG to avoid
having to squash even more stuff into this single patch. They will all
be switched back later in separate commits.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This patch moves the CPU models formatting code from
virQEMUCapsFormatCache into a separate function.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The function just returned cached capabilities without checking whether
they are still valid. We should check that and refresh the capabilities
to make sure we don't return stale data. In other words, we should do
what all other lookup functions do.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The function is made a little bit more readable and the code which
refreshes cached capabilities if they are not valid any more was moved
into a separate function (virQEMUCapsCacheValidate) so that it can be
reused in other places.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
If a user asked for a KVM domain capabilities when KVM is not available,
we would happily return data we got when probing through TCG and
pretended they were relevant for KVM. Let's just report KVM is not
supported to avoid confusion.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
When domain capabilities were introduced we did not have enough data to
decide whether KVM works on the host or not and thus working legacy/VFIO
device assignment was used as a witness. Now that we know whether KVM
was enabled when probing QEMU capabilities (and thus we know it's
working), we can use this knowledge to provide better default value for
virttype.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Since some may depend on the accelerator used when probing QEMU the
cache becomes invalid when KVM becomes available or if it is not
available anymore.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
CPU related capabilities may differ depending on accelerator used when
probing. Let's use KVM if available when probing QEMU and fall back to
TCG. The created capabilities already contain all we need to distinguish
whether KVM or TCG was used:
- KVM was used when probing capabilities:
QEMU_CAPS_KVM is set
QEMU_CAPS_ENABLE_KVM is not set
- TCG was used and QEMU supports KVM, but it failed (e.g., missing
kernel module or wrong /dev/kvm permissions)
QEMU_CAPS_KVM is not set
QEMU_CAPS_ENABLE_KVM is set
- KVM was not used and QEMU does not support it
QEMU_CAPS_KVM is not set
QEMU_CAPS_ENABLE_KVM is not set
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Let's set QEMU_CAPS_KVM and QEMU_CAPS_ENABLE_KVM early so that the rest
of the probing code can use these capabilities to handle KVM/TCG replies
differently.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Using -machine instead of -M for QMP probing is safe because any QEMU
binary which is capable of QMP probing supports -machine.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The code that runs a new QEMU process to be used for probing
capabilities is separated into four reusable functions so that any code
that wants to probe a QEMU process may just follow a few simple steps:
cmd = virQEMUCapsInitQMPCommandNew(...);
virQEMUCapsInitQMPCommandRun(cmd);
/* talk to the running QEMU process using its QMP monitor */
if (reprobeIsRequired) {
virQEMUCapsInitQMPCommandAbort(cmd, ...);
virQEMUCapsInitQMPCommandRun(cmd);
/* talk to the running QEMU process again */
}
virQEMUCapsInitQMPCommandFree(cmd);
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
We have couple of functions that operate over NULL terminated
lits of strings. However, our naming sucks:
virStringJoin
virStringFreeList
virStringFreeListCount
virStringArrayHasString
virStringGetFirstWithPrefix
We can do better:
virStringListJoin
virStringListFree
virStringListFreeCount
virStringListHasString
virStringListGetFirstWithPrefix
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
If libvirt is compiled without NUMACTL support starting libvirtd
reports a libvirt internal error "NUMA isn't available on this host"
without checking if NUMA support is compiled into the libvirt binaries.
This patch adds the missing NUMA support check to prevent the internal error.
It also includes a check if the cgroup controller cpuset is available before
using it.
The error was noticed when libvirtd was restarted with running domains and
on libvirtd start the qemuConnectCgroup gets called during qemuProcessReconnect.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Adjust the device string that is built for vhost-scsi devices so that it
can be invoked from hotplug.
From the QEMU command line, the file descriptors are expect to be numeric only.
However, for hotplug, the file descriptors are expected to begin with at least
one alphabetic character else this error occurs:
# virsh attach-device guest_0001 ~/vhost.xml
error: Failed to attach device from /root/vhost.xml
error: internal error: unable to execute QEMU command 'getfd':
Parameter 'fdname' expects a name not starting with a digit
We also close the file descriptor in this case, so that shutting down the
guest cleans up the host cgroup entries and allows future guests to use
vhost-scsi devices. (Otherwise the guest will silently end.)
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Open /dev/vhost-scsi, and record the resulting file descriptor, so that
the guest has access to the host device outside of the libvirt daemon.
Pass this information, along with data parsed from the XML file, to build
a device string for the qemu command line. That device string will be
for either a vhost-scsi-ccw device in the case of an s390 machine, or
vhost-scsi-pci for any others.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
We already have a "scsi" hostdev subsys type, which refers to a single
LUN that is passed through to a guest. But what of things where
multiple LUNs are passed through via a single SCSI HBA, such as with
the vhost-scsi target? Create a new hostdev subsys type that will
carry this.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Do all the stuff for the vhost-scsi capability in QEMU,
so it's in place for our checks later.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Removed the comment 'Set the migration source' as it isn't valid anymore
and 'start it up' isn't useful as qemuProcessStart() is already a
speaking name.
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Just like in the previous commit, we are not updating CGroups on
chardev hot(un-)plug and thus leaving qemu unable to access any
non-default device users are trying to hotplug.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
If users try to hotplug RNG device with a backend different to
/dev/random or /dev/urandom the whole operation fails as qemu is
unable to access the device. The problem is we don't update
device CGroups during the operation.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
qemuDomainObjExitAgent is unsafe.
First it accesses domain object without domain lock.
Second it uses outdated logic that goes back to commit 79533da1 of
year 2009 when code was quite different. (unref function
instead of unreferencing only unlocked and disposed object
in case of last reference and leaved unlocking to the caller otherwise).
Nowadays this logic may lead to disposing locked object
i guess.
Another problem is that the callers of qemuDomainObjEnterAgent
use domain object again (namely priv->agent) without domain lock.
This patch address these two problems.
qemuDomainGetAgent is dropped as unused.
Sometimes after domain restart agent is unavailabe even
if it is up and running in guest. Diagnostic message is
"QEMU guest agent is not available due to an error"
that is 'priv->agentError' is set. Investiagion shows that
'priv->agent' is not NULL, so error flag is set probably
during domain shutdown process and not cleaned up eventually.
The patch is quite simple - just clean up error flag unconditionally
upon domain stop.
Other hunks address other cases when error flag is not cleaned up.
1. processSerialChangedEvent. We need to clean error flag
unconditionally here too. For example if upon first 'connected' event we
fail to connect and set error flag and then connect on second
'connected' event then error flag will remain set erroneously
and make agent unavailable.
2. qemuProcessHandleAgentEOF. If error flag is set and we get
EOF we need to change state (and diagnostic) from 'error' to
'not connected'.
qemuConnectAgent return -1 or -2 in case of different errors.
A. -1 is a case of unsuccessuful connection to guest agent.
B. -2 is a case of destoyed domain during connection attempt.
All qemuConnectAgent callers handle the first error the same way
so let's move this logic into qemuConnectAgent itself. Patched
function returns 0 in case A and -1 in case B.
Use the util function virHostdevIsSCSIDevice() to simplify if
statements.
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Add missing checks if a hostdev is a subsystem/SCSI device before access
the union member 'subsys'/'scsi'. Also fix indentation and simplify
qemuDomainObjCheckHostdevTaint().
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
New line character in name of domain is now forbidden because it
mess virsh output and can be confusing for users.
Validation of name is done in drivers, after parsing XML to avoid
problems with dissappeared domains which was already created with
new-line char in name.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Commit 3f71c797689a4a70 added 'qemu_id' field to track the id of the cpu
as reported by query-cpus. The patch did not include changes necessary
to propagate the id through the functions matching the data to the
libvirt cpu structures and thus all vcpus had id 0.
Don't use qemuMonitorGetCPUInfo which does a lot of matching to get the
full picture which is not necessary and would be mostly discarded.
Refresh only the vcpu halted state using data from query-cpus.
We don't need to call qemuMonitorGetCPUInfo which is very inefficient to
get data required to update the vcpu 'halted' state.
Add a monitor helper that will retrieve the halted state and return it
in a bitmap so that it can be indexed easily.
Whenever qemuMonitorJSONCheckError returns 0, the "return" object is
guaranteed to exist. Thus virJSONValueObjectGetObject will never fail to
get it. On the other hand, virJSONValueObjectGetArray may fail since the
"return" object may not be an array.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Libvirt's code relies on this fact so don't allow parsing a command line
which would have none.
Libvirtd would crash in the post parse callback on such config.
After a944bd92 we gained support for setting gluster debug level.
However, due to a space we haven't tested whether augeas file
actually works.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
PPC driver needs to convert POWERx_v* legacy CPU model names into POWERx
to maintain backward compatibility with existing domains. This patch
adds a new step into the guest CPU configuration work flow which CPU
drivers can use to convert legacy CPU definitions.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
It was introduced by commit 7a51d9ebb, which started to use
monitor commands without job acquiring, which is unsafe and leads
to simultaneous access to vm->mon structure by different threads.
Crash backtrace is the following (shortened):
Program received signal SIGSEGV, Segmentation fault.
qemuMonitorSend (mon=mon@entry=0x7f4ef4000d20, msg=msg@entry=0x7f4f18e78640) at qemu/qemu_monitor.c:1011
1011 while (!mon->msg->finished) {
0 qemuMonitorSend () at qemu/qemu_monitor.c:1011
1 0x00007f691abdc720 in qemuMonitorJSONCommandWithFd () at qemu/qemu_monitor_json.c:298
2 0x00007f691abde64a in qemuMonitorJSONCommand at qemu/qemu_monitor_json.c:328
3 qemuMonitorJSONQueryCPUs at qemu/qemu_monitor_json.c:1408
4 0x00007f691abcaebd in qemuMonitorGetCPUInfo g@entry=false) at qemu/qemu_monitor.c:1931
5 0x00007f691ab96863 in qemuDomainRefreshVcpuHalted at qemu/qemu_domain.c:6309
6 0x00007f691ac0af99 in qemuDomainGetStatsVcpu at qemu/qemu_driver.c:18945
7 0x00007f691abef921 in qemuDomainGetStats at qemu/qemu_driver.c:19469
8 qemuConnectGetAllDomainStats at qemu/qemu_driver.c:19559
9 0x00007f693382e806 in virConnectGetAllDomainStats at libvirt-domain.c:11546
10 0x00007f6934470c40 in remoteDispatchConnectGetAllDomainStats at remote.c:6267
(gdb) p mon->msg
$1 = (qemuMonitorMessagePtr) 0x0
This change fixes it by calling qemuDomainRefreshVcpuHalted only when job is acquired.
Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
For machinetypes with a pci-root bus (all legacy PCI), libvirt will
make a "fake" reservation for one extra slot prior to assigning
addresses to unaddressed PCI endpoint devices in the domain. This will
trigger auto-adding of a pci-bridge for the final device to be
assigned an address *if that device would have otherwise instead been
the last device on the last available pci-bridge*; thus it assures
that there will always be at least one slot left open in the domain's
bus topology for expansion (which is important both for hotplug (since
a new pci-bridge can't be added while the guest is running) as well as
for offline additions to the config (since adding a new device might
otherwise in some cases require re-addressing existing devices, which
we want to avoid)).
It's important to note that for the above case (legacy PCI), we must
check for the special case of all slots on all buses being occupied
*prior to assigning any addresses*, and avoid attempting to reserve
the extra address in that case, because there is no free address in
the existing topology, so no place to auto-add a pci-bridge for
expansion (i.e. it would always fail anyway). Since that condition can
only be reached by manual intervention, this is acceptable.
For machinetypes with pcie-root (Q35, aarch64 virt), libvirt's
methodology for automatically expanding the bus topology is different
- pcie-root-ports are plugged into slots (soon to be functions) of
pcie-root as needed, and the new endpoint devices are assigned to the
single slot in each pcie-root-port. This is done so that the devices
are, by default, hotpluggable (the slots of pcie-root don't support
hotplug, but the single slot of the pcie-root-port does). Since
pcie-root-ports can only be plugged into pcie-root, and we don't
auto-assign endpoint devices to the pcie-root slots, this means
topology expansion doesn't compete with endpoint devices for slots, so
we don't need to worry about checking for all "useful" slots being
free *prior* to assigning addresses to new endpoint devices - as a
matter of fact, if we attempt to reserve the open slots before the
used slots, it can lead to errors.
Instead this patch just reserves one slot for a "future potential"
PCIe device after doing the assignment for actual devices, but only
if the only PCI controller defined prior to starting address
assignment was pcie-root, and only if we auto-added at least one PCI
controller during address assignment. This assures two things:
1) that reserving the open slots will only be done when the domain is
initially defined, never at any time after, and
2) that if the user understands enough about PCI controllers that they
are adding them manually, that we don't mess up their plan by
adding extras - if they know enough to add one pcie-root-port, or
to manually assign addresses such that no pcie-root-ports are
needed, they know enough to add extra pcie-root-ports if they want
them (this could be called the "libguestfs clause", since
libguestfs needs to be able to create domains with as few
devices/controllers as possible).
This is set to reserve a single free port for now, but could be
increased in the future if public sentiment goes in that direction
(it's easy to increase later, but essentially impossible to decrease)
Real Q35 hardware has an ICH9 chip that includes several integrated
devices at particular addresses (see the file docs/q35-chipset.cfg in
the qemu source). libvirt already attempts to put the first two sets
of ich9 USB2 controllers it finds at 00:1D.* and 00:1A.* to match the
real hardware. This patch does the same for the ich9 "HD audio"
device.
The main inspiration for this patch is that currently the *only*
device in a reasonable "workstation" type virtual machine config that
requires a legacy PCI slot is the audio device, Without this patch,
the standard Q35 machine created by virt-manager will have a
dmi-to-pci-bridge and a pci-bridge just for the sound device; with the
patch (and if you change the sound device model from the default
"ich6" to "ich9"), the machine definition constructed by virt-manager
has absolutely no legacy PCI controllers - any legacy PCI devices
(e.g. video and sound) are on pcie-root as integrated devices.
Previously we added a set of EHCI+UHCI controllers to Q35 machines to
mimic real hardware as closely as possible, but recent discussions
have pointed out that the nec-usb-xhci (USB3) controller is much more
virtualization-friendly (uses less CPU), so this patch switches the
default for Q35 machinetypes to add an XHCI instead (if it's
supported, which it of course *will* be).
Since none of the existing test cases left out USB controllers in the
input XML, a new Q35 test case was added which has *no* devices, so
ends up with only the defaults always put in by qemu, plus those added
by libvirt.
