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>
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>
virQEMUCapsFindTarget is supposed to find an alternative QEMU binary if
qemu-system-$GUEST_ARCH doesn't exist. The alternative is using host
architecture when it is compatible with $GUEST_ARCH. But a special
treatment has to be applied for ppc64le since the QEMU binary is always
called qemu-system-ppc64.
Broken by me in v2.2.0-171-gf2e71550d.
https://bugzilla.redhat.com/show_bug.cgi?id=1403745
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
qemuAgentNotifyEvent accesses monitor structure and is called on qemu
reset/shutdown/suspend events under domain lock. Other monitor
functions on the other hand take monitor lock and don't hold domain lock.
Thus it is possible to have risky simultaneous access to the structure
from 2 threads. Let's take monitor lock here to make access exclusive.
In case of 0 filesystems *info is not set while according
to virDomainGetFSInfo contract user should call free on it even
in case of 0 filesystems. Thus we need to properly set
it. NULL will be enough as free eats NULLs ok.
The libvirt-domain.h documentation indicates that for a qcow2 file
in a filesystem being used for a backing store should report the disk
space occupied by a file; however, commit id '15fa84ac' altered the
code to trust that the wr_highest_offset should be used whenever
wr_highest_offset_valid was set.
As it turns out this will lead to indeterminite results. For an active
domain when qemu hasn't yet had the need to find the wr_highest_offset
value, qemu will report 0 even though qemu-img will report the proper
disk size. This causes reporting of the following XML:
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/path/to/test-1g.qcow2'/>
to be as follows:
Capacity: 1073741824
Allocation: 0
Physical: 1074139136
with qemu-img indicating:
image: /path/to/test-1g.qcow2
file format: qcow2
virtual size: 1.0G (1073741824 bytes)
disk size: 1.0G
Once the backing source file is opened on the guest, then wr_highest_offset
is updated, but only to the high water mark and not the size of the file.
This patch will adjust the logic to check for the file backed qcow2 image
and enforce setting the allocation to the returned 'physical' value, which
is the 'actual-size' value from a 'query-block' operation.
NB: The other consumer of the wr_highest_offset output (GetAllDomainStats)
has a contract that indicates 'allocation' is the offset of the highest
written sector, so it doesn't need adjustment.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Instead of having duplicated code in qemuStorageLimitsRefresh and
virStorageBackendUpdateVolTargetInfo to get capacity specific data
about the storage backing source or volume -- create a common API
to handle the details for both.
As a side effect, virStorageFileProbeFormatFromBuf returns to being
a local/static helper to virstoragefile.c
For the QEMU code - if the probe is done, then the format is saved so
as to avoid future such probes.
For the storage backend code, there is no need to deal with the probe
since we cannot call the new API if target->format == NONE.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Instead of having duplicated code in qemuStorageLimitsRefresh and
virStorageBackendUpdateVolTargetInfoFD to fill in the storage backing
source or volume allocation, capacity, and physical values - create a
common API that will handle the details for both.
The common API will fill in "default" capacity values as well - although
those more than likely will be overridden by subsequent code. Having just
one place to make the determination of what the values should be will
make things be more consistent.
For the QEMU code - the data filled in will be for inactive domains
for the GetBlockInfo and DomainGetStatsOneBlock API's. For the storage
backend code - the data will be filled in during the volume updates.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Commit id '8dc27259' introduced virStorageSourceUpdateBlockPhysicalSize
in order to retrieve the physical size for a block backed source device
for an active domain since commit id '15fa84ac' changed to use the
qemuMonitorGetAllBlockStatsInfo and qemuMonitorBlockStatsUpdateCapacity
API's to (essentially) retrieve the "actual-size" from a 'query-block'
operation for the source device.
However, the code only was made functional for a BLOCK backing type
and it neglected to use qemuOpenFile, instead using just open. After
the open the block lseek would find the end of the block and set the
physical value, close the fd and return.
Since the code would return 0 immediately if the source device wasn't
a BLOCK backed device, the physical would be displayed incorrectly,
such as follows in domblkinfo for a file backed source device:
Capacity: 1073741824
Allocation: 0
Physical: 0
This patch will modify the algorithm to get the physical size for other
backing types and it will make use of the qemuDomainStorageOpenStat
helper in order to open/stat the source file depending on its type.
The qemuDomainGetStatsOneBlock will no longer inhibit printing errors,
but it will still ignore them leaving the physical value set to 0.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Split out the opening of the file and fetch of the stat buffer into a
helper qemuDomainStorageOpenStat. This will handle either opening the
local or remote storage.
Additionally split out the cleanup of that into a separate helper
qemuDomainStorageCloseStat which will either close the file or
call the virStorageFileDeinit function.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Originally added by commit id '89646e69' prior to commit id '15fa84ac'
and '71d2c172' which ensured that qemuStorageLimitsRefresh was only called
for inactive domains.
Adjust the comment describing the need for FIXME and move all the text
to the function description.
Signed-off-by: John Ferlan <jferlan@redhat.com>
In preparation to the code move to virnetdevtap.c, this change:
* renames virNetInterfaceStats to virNetDevTapInterfaceStats
* changes 'path' to 'ifname', to use the same vocable as other
method in virnetdevtap.c.
* Add the attributes checker
When vhostuser interfaces are used, the interface statistics
are not available in /proc/net/dev.
This change looks at the openvswitch interfaces statistics
tables to provide this information for vhostuser interface.
Note that in openvswitch world drop/error doesn't always make sense
for some interface type. When these informations are not available we
set them to 0 on the virDomainInterfaceStats.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
There's nothing to compress if the requested snapshot memory format is
set to 'raw' explicitly. After commit 9e14689ea libvirt would try to
run /sbin/raw to process the memory stream if the qemu.conf option
snapshot_image_format is set.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1402726
Since its introduction in 2012 this internal API did nothing.
Moreover we have the same API that does exactly the same:
virSecurityManagerDomainSetPathLabel.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
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>
So far this function takes virDomainObjPtr which:
1) is an overkill,
2) might be not available in all the places we will use it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Qemu 2.8.0+ changes arguments structure for blockdev-add in the effort
to make it finally stable. Since libvirt recently added the detection of
gluster debug support relying on the old syntax we need to add the new
as well.
With current perf framework, this patch adds support and documentation
for the branch_instructions perf event.
Signed-off-by: Nitesh Konkar <nitkon12@linux.vnet.ibm.com>
Add in the block I/O throttling group parameter to the command line
if supported. If not supported, fail command creation.
Add the xml2argvtest for testing.
Signed-off-by: John Ferlan <jferlan@redhat.com>
Rather than have multiple bool values, create a single enum with bits
representing what fields are set. Fields are generally set in groups
of 3 (read, write, total).
Currently we build the JSON object for the "block_set_io_throttle"
command using the knowledge that a NULL for a support*Options boolean
would essentially ignore the rest of the arguments.
This may not work properly if some capability was backported, plus it just
looks rather ugly. So instead, build the "base" arguments and then if
the support*Option bool capability is set, add in the arguments on the fly.
Then append those arguments to the basic command and send to qemu.
Rather than using negative logic and setting the maxparams to a lesser
value based on which capabilities exist, alter the logic to modify the
maxparams based on a base value plus the found capabilities. Reduces the
chance that some backported feature produces an incorrect value.
Two reasons:
1.in none hotplug, we will pass it. We can see from libvirt function
qemuBuildVhostuserCommandLine
2.qemu will use this vetcor num to init msix table. If we don't pass, qemu
will use default value, this will cause VM can only use default value
interrupts at most.
Signed-off-by: gaohaifeng <gaohaifeng.gao@huawei.com>
Consider the following XML snippets:
$ cat scsicontroller.xml
<controller type='scsi' model='virtio-scsi' index='0'/>
$ cat scsihostdev.xml
<hostdev mode='subsystem' type='scsi'>
<source>
<adapter name='scsi_host0'/>
<address bus='0' target='8' unit='1074151456'/>
</source>
</hostdev>
If we create a guest that includes the contents of scsihostdev.xml,
but forget the virtio-scsi controller described in scsicontroller.xml,
one is silently created for us. The same holds true when attaching
a hostdev before the matching virtio-scsi controller.
(See qemuDomainFindOrCreateSCSIDiskController for context.)
Detaching the hostdev, followed by the controller, works well and the
guest behaves appropriately.
If we detach the virtio-scsi controller device first, any associated
hostdevs are detached for us by the underlying virtio-scsi code (this
is fine, since the connection is broken). But all is not well, as the
guest is unable to receive new virtio-scsi devices (the attach commands
succeed, but devices never appear within the guest), nor even be
shutdown, after this point.
While this is not libvirt's problem, we can prevent falling into this
scenario by checking if a controller is being used by any hostdev
devices. The same is already done for disk elements today.
Applying this patch and then using the XML snippets from earlier:
$ virsh detach-device guest_01 scsicontroller.xml
error: Failed to detach device from scsicontroller.xml
error: operation failed: device cannot be detached: device is busy
$ virsh detach-device guest_01 scsihostdev.xml
Device detached successfully
$ virsh detach-device guest_01 scsicontroller.xml
Device detached successfully
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Although nearly all host devices that are assigned to guests using
VFIO ("<hostdev>" devices in libvirt) are physically PCI Express
devices, until now libvirt's PCI address assignment has always
assigned them addresses on legacy PCI controllers in the guest, even
if the guest's machinetype has a PCIe root bus (e.g. q35 and
aarch64/virt).
This patch tries to assign them to an address on a PCIe controller
instead, when appropriate. First we do some preliminary checks that
might allow setting the flags without doing any extra work, and if
those conditions aren't met (and if libvirt is running privileged so
that it has proper permissions), we perform the (relatively) time
consuming task of reading the device's PCI config to see if it is an
Express device. If this is successful, the connect flags are set based
on the result, but if we aren't able to read the PCI config (most
likely due to the device not being present on the system at the time
of the check) we assume it is (or will be) an Express device, since
that is almost always the case anyway.
If libvirtd is running unprivileged, it can open a device's PCI config
data in sysfs, but can only read the first 64 bytes. But as part of
determining whether a device is Express or legacy PCI,
qemuDomainDeviceCalculatePCIConnectFlags() will be updated in a future
patch to call virPCIDeviceIsPCIExpress(), which tries to read beyond
the first 64 bytes of the PCI config data and fails with an error log
if the read is unsuccessful.
In order to avoid creating a parallel "quiet" version of
virPCIDeviceIsPCIExpress(), this patch passes a virQEMUDriverPtr down
through all the call chains that initialize the
qemuDomainFillDevicePCIConnectFlagsIterData, and saves the driver
pointer with the rest of the iterdata so that it can be used by
qemuDomainDeviceCalculatePCIConnectFlags(). This pointer isn't used
yet, but will be used in an upcoming patch (that detects Express vs
legacy PCI for VFIO assigned devices) to examine driver->privileged.
Restarting libvirtd on the source host at the end of migration when a
domain is already running on the destination would cause image labels to
be reset effectively killing the domain. Commit e8d0166e1d fixed similar
issue on the destination host, but kept the source always resetting the
labels, which was mostly correct except for the specific case handled by
this patch.
https://bugzilla.redhat.com/show_bug.cgi?id=1343858
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Post-copy migration needs bi-directional communication between the
source and the destination QEMU processes, which is not supported by
tunnelled migration.
https://bugzilla.redhat.com/show_bug.cgi?id=1371358
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
