Documents in formatdomain.html that when migrating a guest
defined with the host-passthrough CPU model from a machine that
is running on a newer CPU model than the destination machine's
CPU model, it is very likely that the guest will crash upon
arrival.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Finally, now that all APIs have been introduced, wire them up to virt-admin
and introduce daemon-log-outputs and daemon-log-filters commands.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Enable libvirt users to modify daemon's logging output settings from outside.
If either an empty string or NULL is passed, a default logging output will be
used the same way as it would be in case writing an empty string to the
libvirtd.conf
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Now that virLog{Get,Set}DefaultOutput routines are introduced we can wire them
up to the daemon's logging initialization code. Also, change the order of
operations a bit so that we still strictly honor our precedence of settings:
cmdline > env > config now that outputs and filters are not appended anymore.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Along with an empty string, it should also be possible for users to pass
NULL to the public APIs which in turn would trigger a routine(future
work) responsible for defining an appropriate default logging output
given the current circumstances.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
These helpers will manage the log destination defaults (fetch/set). The reason
for this is to stay consistent with the current daemon's behaviour with respect
to /etc/libvirt/<daemon>.conf file, since both assignment of an empty string
or not setting the log output variable at all trigger the daemon's decision on
the default log destination which depends on whether the daemon runs daemonized
or not.
This patch also changes the logic of the selection of the default
logging output compared to how it is done now. The main difference though is
that we should only really care if we're running daemonized or not, disregarding
the fact of (not) having a TTY completely (introduced by commit eba36a3878) as
that should be of the libvirtd's parent concern (what FD it will pass to it).
Before:
if (godaemon || !hasTTY):
if (journald):
use journald
if (godaemon):
if (privileged):
use SYSCONFIG/libvirtd.log
else:
use XDG_CONFIG_HOME/libvirtd.log
else:
use stderr
After:
if (godaemon):
if (journald):
use journald
else:
if (privileged):
use SYSCONFIG/libvirtd.log
else:
use XDG_CONFIG_HOME/libvirtd.log
else:
use stderr
Signed-off-by: Erik Skultety <eskultet@redhat.com>
External disk-only snapshots with recent enough qemu don't require
libvirt to pause the VM. The logic determining when to resume cpus was
slightly flawed and attempted to resume them even if they were not
paused by the snapshot code. This normally was not a problem, but with
locking enabled the code would attempt to acquire the lock twice.
The fallout of this bug would be a error from the API, but the actual
snapshot being created. The bug was introduced with when adding support
for external snapshots with memory (checkpoints) in commit f569b87.
Resolves problems described by:
https://bugzilla.redhat.com/show_bug.cgi?id=1403691
After qemu delivers the resume event it's already running and thus it's
too late to enter lockspaces since it may already have modified the
disk. The code only creates false log entries in the case when locking
is enabled. The lockspace needs to be acquired prior to starting cpus.
Given how intrusive previous patches are, it might happen that
there's a bug or imperfection. Lets give users a way out: if they
set 'namespaces' to an empty array in qemu.conf the feature is
suppressed.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Instead of trying to fix our security drivers, we can use a
simple trick to relabel paths in both namespace and the host.
I mean, if we enter the namespace some paths are still shared
with the host so any change done to them is visible from the host
too.
Therefore, we can just enter the namespace and call
SetAllLabel()/RestoreAllLabel() from there. Yes, it has slight
overhead because we have to fork in order to enter the namespace.
But on the other hand, no complexity is added to our code.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
When starting a domain and separate mount namespace is used, we
have to create all the /dev entries that are configured for the
domain.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Prime time. When it comes to spawning qemu process and
relabelling all the devices it's going to touch, there's inherent
race with other applications in the system (e.g. udev). Instead
of trying convincing udev to not touch libvirt managed devices,
we can create a separate mount namespace for the qemu, and mount
our own /dev there. Of course this puts more work onto us as we
have to maintain /dev files on each domain start and device
hot(un-)plug. On the other hand, this enhances security also.
From technical POV, on domain startup process the parent
(libvirtd) creates:
/var/lib/libvirt/qemu/$domain.dev
/var/lib/libvirt/qemu/$domain.devpts
The child (which is going to be qemu eventually) calls unshare()
to create new mount namespace. From now on anything that child
does is invisible to the parent. Child then mounts tmpfs on
$domain.dev (so that it still sees original /dev from the host)
and creates some devices (as explained in one of the previous
patches). The devices have to be created exactly as they are in
the host (including perms, seclabels, ACLs, ...). After that it
moves $domain.dev mount to /dev.
What's the $domain.devpts mount there for then you ask? QEMU can
create PTYs for some chardevs. And historically we exposed the
host ends in our domain XML allowing users to connect to them.
Therefore we must preserve devpts mount to be shared with the
host's one.
To make this patch as small as possible, creating of devices
configured for domain in question is implemented in next patches.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is a list of devices that qemu needs for its run (apart from
what's configured for domain). The devices on the list are
enabled in the CGroups by default so they will be good candidates
for initial /dev for new qemu.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function in near future so that we know what
/dev device corresponds to the SCSI device.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function in near future so that we know what
/dev device corresponds to the SCSI device.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We will need this function in near future so that we know what
/dev device corresponds to the USB device.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Namely, virFileGetACLs, virFileSetACLs, virFileFreeACLs and
virFileCopyACLs. These functions are going to be required when we
are creating /dev for qemu. We have copy anything that's in
host's /dev exactly as is. Including ACLs.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
libvirt libxl picks its own default with respect to the default NIC
to use. libxlMakeNic is the one responsible for this and on boot it
picks LIBXL_NIC_TYPE_VIF_IOEMU for HVM domains such that it accomodates
both PV and emulated one. The good behaving guest at boot will then
select the pv and unplug the emulated device.
Now, on HVM when attaching an interface it will pick the same default
that is LIBXL_NIC_TYPE_VIF_IOEMU which as a result will fail the attach
(see xen commit 32e9d0f ("libxl: nic type defaults to vif in hotplug for
hvm guest"). Xen doesn't yet support the hotplug of emulated devices,
but we don't want to rule out that case either, which might get support
in the future. Hence we simply reverse the defaults when we are
attaching the interface which allows libvirt to prefer the PV nic first
without adding "model='netfront'" following the same pattern as above
commit. Also to avoid ruling out the emulated one we set to
LIBXL_NIC_TYPE_IOEMU when setting a model type that is not 'netfront'.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
The virDomainSendProcessSignal method says the flags values
come from virDomainProcessSignalFlag, but this enum has
never existed. No flags are needed for this method.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Almost none of our virJSONValue*Get* functions accept const virJSONValue
pointers and it wouldn't even make sense since we sometimes modify what
we get. And because there is no reason for preventing callers of
virJSONValueObjectForeachKeyValue from modifying the values they get in
each iteration we can just stop doing it.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Using a variable named 'stat' clashes with the system function
'stat()' causing compiler warnings on some platforms
cc1: warnings being treated as errors
../../src/qemu/qemu_monitor_text.c: In function 'parseMemoryStat':
../../src/qemu/qemu_monitor_text.c:604: error: declaration of 'stat' shadows a global declaration [-Wshadow]
/usr/include/sys/stat.h:455: error: shadowed declaration is here [-Wshadow]
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If the cpuset cgroup controller is disabled in /etc/libvirt/qemu.conf
QEMU virtual machines can in principle use all host CPUs, even if they
are hot plugged, if they have no explicit CPU affinity defined.
However, there's libvirt code supposed to handle the situation where
the libvirt daemon itself is not using all host CPUs. The code in
qemuProcessInitCpuAffinity attempts to set an affinity mask including
all defined host CPUs. Unfortunately, the resulting affinity mask for
the process will not contain the offline CPUs. See also the
sched_setaffinity(2) man page.
That means that even if the host CPUs come online again, they won't be
used by the QEMU process anymore. The same is true for newly hot
plugged CPUs. So we are effectively preventing that QEMU uses all
processors instead of enabling it to use them.
It only makes sense to set the QEMU process affinity if we're able
to actually grow the set of usable CPUs, i.e. if the process affinity
is a subset of the online host CPUs.
There's still the chance that for some reason the deliberately chosen
libvirtd affinity matches the online host CPU mask by accident. In this
case the behavior remains as it was before (CPUs offline while setting
the affinity will not be used if they show up later on).
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
The functions to retrieve online and present host CPU information
are only supported on Linux for the time being.
This leads to runtime errors if these function are used on other
platforms. To avoid that, code in higher levels using the functions
must replicate the conditional compilation in higher level which
is error prone (and is plainly spoken ugly).
Adding a function virHostCPUHasBitmap that can be used to check
for host CPU bitmap support.
NB: There are other functions including the host CPU count that
are lacking support on all platforms, but they are too essential
in order to be bypassed.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
