Commit Graph

5908 Commits

Author SHA1 Message Date
Nitesh Konkar
9ae79400ff perf: add stalled_cycles_backend perf event support
This patch adds support and documentation for
the stalled_cycles_backend perf event.

Signed-off-by: Nitesh Konkar <nitkon12@linux.vnet.ibm.com>
2016-12-15 16:47:05 -05:00
Nitesh Konkar
060c159b08 perf: add stalled_cycles_frontend perf event support
This patch adds support and documentation
for the stalled_cycles_frontend perf event.

Signed-off-by: Nitesh Konkar <nitkon12@linux.vnet.ibm.com>
2016-12-15 16:47:05 -05:00
Nitesh Konkar
7d34731067 perf: add bus_cycles perf event support
This patch adds support and documentation
for the bus_cycles perf event.

Signed-off-by: Nitesh Konkar <nitkon12@linux.vnet.ibm.com>
2016-12-15 16:47:05 -05:00
Peter Krempa
4b951d1e38 qemu: snapshot: Don't attempt to resume cpus if they were not paused
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
2016-12-15 09:46:41 +01:00
Peter Krempa
e8f167a623 qemu: monitor: Don't resume lockspaces in resume event handler
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.
2016-12-15 09:46:41 +01:00
Michal Privoznik
f444faa94a qemu: Enable mount namespace
https://bugzilla.redhat.com/show_bug.cgi?id=1404952

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-15 09:25:16 +01:00
Michal Privoznik
661887f558 qemu: Let users opt-out from containerization
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
f95c5c48d4 qemu: Manage /dev entry on RNG hotplug
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
f5fdf23a68 qemu: Manage /dev entry on chardev hotplug
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
6e57492839 qemu: Manage /dev entry on hostdev hotplug
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
81df21507b qemu: Manage /dev entry on disk hotplug
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
eadaa97548 qemu: Enter the namespace on relabelling
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
2160f338a7 qemu: Prepare RNGs when starting a domain
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
8ec8a8c5ff qemu: Prepare inputs when starting a domain
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
2c654490f3 qemu: Prepare TPM when starting a domain
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
4e4451019c qemu: Prepare chardevs when starting a domain
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
73267cec46 qemu: Prepare hostdevs when starting a domain
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
054202d020 qemu: Prepare disks when starting a domain
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
bb4e529664 qemu: Spawn qemu under mount namespace
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>
2016-12-15 09:25:16 +01:00
Michal Privoznik
a5896e8ca4 qemu_cgroup: Expose defaultDeviceACL
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>
2016-12-15 09:25:16 +01:00
Daniel P. Berrange
a81cfb649d Avoid variable named 'stat'
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>
2016-12-14 12:17:08 +00:00
Viktor Mihajlovski
283e290434 qemu: Allow use of hot plugged host CPUs if no affinity set
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>
2016-12-13 18:25:00 -05:00
Jiri Denemark
f00c00475f qemu: Fix virQEMUCapsFindTarget on ppc64le
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>
2016-12-13 22:11:33 +01:00
Nitesh Konkar
8981d7925e perf: add branch_misses perf event support
This patch adds support and documentation
for the branch_misses perf event.

Signed-off-by: Nitesh Konkar <nitkon12@linux.vnet.ibm.com>
2016-12-12 18:04:52 -05:00
Nikolay Shirokovskiy
cdd6819318 qemu: agent: take monitor lock in qemuAgentNotifyEvent
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.
2016-12-12 17:14:11 -05:00
Nikolay Shirokovskiy
c9a191fc48 qemu: don't use vm when lock is dropped in qemuDomainGetFSInfo
Current call to qemuAgentGetFSInfo in qemuDomainGetFSInfo is
unsafe. Domain lock is dropped and we use vm->def. Let's make
def copy to fix that.
2016-12-12 17:14:11 -05:00
Nikolay Shirokovskiy
3ab9652a86 qemu: agent: fix uninitialized var case in qemuAgentGetFSInfo
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.
2016-12-12 17:14:11 -05:00
John Ferlan
cf436a560d qemu: Fix GetBlockInfo setting allocation from wr_highest_offset
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>
2016-12-12 16:04:17 -05:00
John Ferlan
9d734b60a7 util: Introduce virStorageSourceUpdateCapacity
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>
2016-12-12 16:04:17 -05:00
John Ferlan
3039ec962e util: Introduce virStorageSourceUpdateBackingSizes
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>
2016-12-12 16:04:17 -05:00
John Ferlan
c5f6151390 util: Introduce virStorageSourceUpdatePhysicalSize
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>
2016-12-12 16:04:17 -05:00
John Ferlan
a7fea19fcd qemu: Introduce helper qemuDomainStorageUpdatePhysical
Currently just a shim to call virStorageSourceUpdateBlockPhysicalSize

Signed-off-by: John Ferlan <jferlan@redhat.com>
2016-12-12 16:04:17 -05:00
John Ferlan
732af77cce qemu: Add helpers to handle stat data for qemuStorageLimitsRefresh
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>
2016-12-12 16:04:17 -05:00
John Ferlan
7149d1693d qemu: Clean up description for qemuStorageLimitsRefresh
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>
2016-12-12 16:04:17 -05:00
Nikolay Shirokovskiy
1215965a4c qemu: mark user defined websocket as used
We need extra state variable to distinguish between autogenerated
and user defined cases after auto generation is done.
2016-12-09 07:54:34 -05:00
Nikolay Shirokovskiy
b07cfd724f qemu: Refactor qemuProcessGraphicsReservePorts
Use switch for enums rather than if/else conditions.
2016-12-09 07:40:46 -05:00
Michal Privoznik
b492f7ef0f qemuGetDomainHugepagePath: Initialize @ret
The variable may be used uninitialized in this function.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-12-09 10:51:37 +01:00
Mehdi Abaakouk
e0d893e86d Move virstat.c code to virnetdevtap.c
This is just a code move of virstat.c to virnetdevtap.c
2016-12-09 10:28:07 +01:00
Mehdi Abaakouk
9b6de7c506 virstat: fix signature of virstat helper
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
2016-12-09 10:27:56 +01:00
Mehdi Abaakouk
013df874db Gathering vhostuser interface stats with ovs
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>
2016-12-09 10:23:09 +01:00
Peter Krempa
a4ed5b4212 qemu: Don't try to find compression program for "raw" memory images
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
2016-12-08 17:12:54 +01:00
Michal Privoznik
ce937d3710 security: Drop virSecurityManagerSetHugepages
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>
2016-12-08 15:45:52 +01:00
Michal Privoznik
f55afd83b1 qemu: Create hugepage path on per domain basis
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>
2016-12-08 15:45:52 +01:00
Michal Privoznik
7ed6934f3b virDomainObjGetShortName: take virDomainDef
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>
2016-12-08 15:45:52 +01:00
Peter Krempa
cf44dc072a qemu: capabilities: Add gluster.debug_level detection for 2.8.0+
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.
2016-12-07 13:34:22 +01:00
Nitesh Konkar
8546adf80b perf: add one more perf event support
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>
2016-12-07 07:03:57 -05:00
John Ferlan
1ff38366b8 qemu: Add the group name option to the iotune command line
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>
2016-12-05 18:30:38 -05:00
John Ferlan
c53bd25b13 qemu: Add support for parsing iotune group setting
Add support to read/parse the iotune group setting for qemu.

Signed-off-by: John Ferlan <jferlan@redhat.com>
2016-12-05 18:12:08 -05:00
John Ferlan
d0f82df205 qemu: Adjust various bool BlockIoTune set_ values into a single mask
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).
2016-12-05 18:12:08 -05:00
John Ferlan
ad9f127302 qemu: Alter qemuMonitorJSONSetBlockIoThrottle command logic
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.
2016-12-05 18:12:08 -05:00
John Ferlan
c84ad82a2d qemu: Adjust maxparams logic for qemuDomainGetBlockIoTune
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.
2016-12-05 18:12:08 -05:00
John Ferlan
d3364dfdc8 caps: Add new capability for the iotune group name
Add the capability to detect if the qemu binary can support the feature
to use throttling.group.
2016-12-05 18:12:08 -05:00
Yuri Chornoivan
ff8e021225 Fix minor typos 2016-12-02 09:25:13 +01:00
gaohaifeng
f81b33b50c qemuDomainAttachNetDevice: pass mq and vectors for vhost-user with multiqueue
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>
2016-12-01 15:02:35 +01:00
Eric Farman
655429a0d4 qemu: Prevent detaching SCSI controller used by hostdev
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>
2016-11-30 17:16:47 -05:00
Laine Stump
70249927b7 qemu: assign VFIO devices to PCIe addresses when appropriate
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.
2016-11-30 15:41:57 -05:00
Laine Stump
9b0848d523 qemu: propagate virQEMUDriver object to qemuDomainDeviceCalculatePCIConnectFlags
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.
2016-11-30 15:28:07 -05:00
Jiri Denemark
0355de2e77 qemuProcessReconnect: Avoid relabeling images after migration
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>
2016-11-29 12:37:04 +01:00
Jiri Denemark
ee3ea86b37 qemu: Report tunnelled post-copy migration as unsupported
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>
2016-11-29 12:31:25 +01:00
Peter Krempa
b87a11340f qemu: capabilities: Don't partially reprope caps on process reconnect
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.
2016-11-28 10:02:36 +01:00
Jiri Denemark
a1adfb0f06 qemu: Add support for unavailable-features
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>
2016-11-28 09:11:22 +01:00
Jiri Denemark
73411a7ff1 qemu: Avoid reporting "host" as a supported CPU model
"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>
2016-11-25 20:59:19 +01:00
Jiri Denemark
7bf6f345e0 qemu: Probe CPU models for KVM and TCG
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>
2016-11-25 20:34:27 +01:00
Jiri Denemark
7c95619cb1 qemu: Introduce virQEMUCapsFormatCPUModels
This patch moves the CPU models formatting code from
virQEMUCapsFormatCache into a separate function.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2016-11-25 20:34:26 +01:00
Jiri Denemark
1bdcd7a4ee qemu: Introduce virQEMUCapsLoadCPUModels
This patch moves the CPU models parsing code from virQEMUCapsLoadCache
into a separate function.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
2016-11-25 20:34:26 +01:00
Jiri Denemark
f9d57f2b57 qemu: Refresh caps in virQEMUCapsCacheLookupByArch
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
72e5aa4e1e qemu: Refactor virQEMUCapsCacheLookup
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
cd51b90fbf qemu: Don't return unusable virttype in domain capabilities
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
8f55eef246 qemu: Use saner defaults for domain capabilities
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
d87df9bd39 qemu: Discard caps cache when KVM availability changes
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
25ba9c31f5 qemu: Enable KVM when probing capabilities
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
429a7b231c qemu: Probe KVM state earlier
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
e73447f693 qemu: Use -machine when probing capabilities via QMP
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>
2016-11-25 20:34:26 +01:00
Jiri Denemark
4c5d05ea8a qemu: Make QMP probing process reusable
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>
2016-11-25 20:34:26 +01:00
Michal Privoznik
c2a5a4e7ea virstring: Unify string list function names
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>
2016-11-25 13:54:05 +01:00
Boris Fiuczynski
b178fa8ecb qemu: fix internal error: NUMA isn't available on this host
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>
2016-11-25 09:48:41 +01:00
Eric Farman
8c6d365373 qemu: Allow hotplug of vhost-scsi device
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>
2016-11-24 12:16:23 -05:00
Eric Farman
9cc26dc622 qemu: Add vhost-scsi string for -device parameter
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>
2016-11-24 12:16:19 -05:00
Eric Farman
fc0e627bac Introduce framework for a hostdev SCSI_host subsystem type
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>
2016-11-24 12:15:26 -05:00
Eric Farman
c271fc1f35 qemu: Introduce vhost-scsi capability
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>
2016-11-24 12:15:26 -05:00
Marc Hartmayer
b270ef9981 qemu: Removed an outdated comment in qemuDomainSaveImageStartVM()
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>
2016-11-23 12:33:38 -05:00
Michal Privoznik
5d9c2c7081 qemu: Update cgroup on chardev hotplug
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>
2016-11-23 16:38:02 +01:00
Michal Privoznik
085692c8bb qemu: Update cgroup on RNG hotplug
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>
2016-11-23 16:37:57 +01:00
Nikolay Shirokovskiy
aaf2992d90 qemu: agent: fix unsafe agent access
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.
2016-11-23 11:31:28 +03:00
Nikolay Shirokovskiy
3c1c56781d qemu: drop write-only agentStart 2016-11-23 11:31:14 +03:00
Nikolay Shirokovskiy
6ba861ae36 qemu: agent: cleanup agent error flag correctly
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'.
2016-11-23 11:14:44 +03:00
Nikolay Shirokovskiy
f5109f20ff qemu: agent: remove redundant check 2016-11-23 11:14:28 +03:00
Nikolay Shirokovskiy
851ae08e3e qemu: agent: handle agent connection errors in one place
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.
2016-11-23 11:14:11 +03:00
Marc Hartmayer
1c122e737e Refactoring: Use virHostdevIsSCSIDevice()
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>
2016-11-22 14:37:36 +01:00
Marc Hartmayer
505bc9b025 qemu: Fix improper union member access on hostdevs
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>
2016-11-22 14:37:36 +01:00
Sławek Kapłoński
6c98ac2c62 Forbid new-line char in name of new domain
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>
2016-11-22 14:35:14 +01:00
Peter Krempa
b6afa9a8b5 qemu: monitor: Properly propagate the 'qemu_id' field through the matcher
Commit 3f71c79768 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.
2016-11-22 10:44:17 +01:00
Peter Krempa
0df2524acb qemu: domain: Refresh vcpu halted state using qemuMonitorGetCpuHalted
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.
2016-11-21 17:19:48 +01:00
Peter Krempa
5d885f4ff3 qemu: monitor: Extract halted state to a bitmap indexed by cpu id
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.
2016-11-21 17:19:48 +01:00
Peter Krempa
3f71c79768 qemu: monitor: Extract qemu cpu id along with other data
Storing of the ID will allow simpler extraction of data present only in
query-cpus without the need to call qemuMonitorGetCPUInfo in statistics
paths.
2016-11-21 17:19:48 +01:00
Jiri Denemark
2e0d6cdec4 qemu_monitor_json: Don't check existence of "return" object
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>
2016-11-21 16:14:52 +01:00
Peter Krempa
4fa7ba0b32 qemu: process: Set current vcpu count to maximum if it was not specified
Mimic qemu's behavior on the given command line.
2016-11-21 14:35:20 +01:00
Peter Krempa
d3734b7a1d qemu: parse: Assign maximum cpu count from topology if not provided
qemu uses this if 'maxcpus' is not present. Do the same in the parsing
code.
2016-11-21 14:35:20 +01:00
Peter Krempa
0d9a76de6d qemu: parse: Assign topology info earlier
Qemu can also use the topology to calculate the total vcpu count. To
allow parsing this move the assignment earlier.
2016-11-21 14:35:20 +01:00
Peter Krempa
d78a8c26c2 qemu: parse: Allow the 'cpus=' prefix for current cpu number
qemu allows following syntax:

  -smp [cpus=]n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus]

Allow the "cpus" prefix.
2016-11-21 14:35:20 +01:00