This eliminates the warning message reported in:
https://bugzilla.redhat.com/show_bug.cgi?id=624447
It was caused by a failure to open an image file that is not
accessible by root (the uid libvirtd is running as) because it's on a
root-squash NFS share, owned by a different user, with permissions of
660 (or maybe 600).
The solution is to use virFileOpenAs() rather than open(). The
codepath that generates the error is during qemuSetupDiskCGroup(), but
the actual open() is in a lower-level generic function called from
many places (virDomainDiskDefForeachPath), so some other pieces of the
code were touched just to add dummy (or possibly useful) uid and gid
arguments.
Eliminating this warning message has the nice side effect that the
requested operation may even succeed (which in this case isn't
necessary, but shouldn't hurt anything either).
filter 0-device-weight when:
- getting blkio parameters with --config
- starting up a domain
When testing with blkio, I found these issues:
(dom is down)
virsh blkiotune dom --device-weights /dev/sda,300,/dev/sdb,500
virsh blkiotune dom --device-weights /dev/sda,300,/dev/sdb,0
virsh blkiotune dom
weight : 800
device_weight : /dev/sda,200,/dev/sdb,0
# issue 1: shows 0 device weight of /dev/sdb that may confuse user
(continued)
virsh start dom
# issue 2: If /dev/sdb doesn't exist, libvirt refuses to bring the
# dom up because it wants to set the device weight to 0 of a
# non-existing device. Since 0 means no weight-limit, we really don't
# have to set it.
The cpu bandwidth is applied at the vcpu group level. We should apply it
at the vm group level too, because the vm may do heavy I/O, and it will affect
the other vm.
We apply cpu bandwidth at the vcpu and the vm group level, so we must ensure
that max(child_quota) <= parent_quota when we modify cpu bandwidth.
The LXC and UML drivers can both make use of auditing. Move
the qemu_audit.{c,h} files to src/conf/domain_audit.{c,h}
* src/conf/domain_audit.c: Rename from src/qemu/qemu_audit.c
* src/conf/domain_audit.h: Rename from src/qemu/qemu_audit.h
* src/Makefile.am: Remove qemu_audit.{c,h}, add domain_audit.{c,h}
* src/qemu/qemu_audit.h, src/qemu/qemu_cgroup.c,
src/qemu/qemu_command.c, src/qemu/qemu_driver.c,
src/qemu/qemu_hotplug.c, src/qemu/qemu_migration.c,
src/qemu/qemu_process.c: Update for changed audit API names
Detected by Coverity. All existing callers happen to be in
range, so this isn't too serious.
* src/qemu/qemu_cgroup.c (qemuCgroupControllerActive): Check
bounds before dereference.
These VIR_XXXX0 APIs make us confused, use the non-0-suffix APIs instead.
How do these coversions works? The magic is using the gcc extension of ##.
When __VA_ARGS__ is empty, "##" will swallow the "," in "fmt," to
avoid compile error.
example: origin after CPP
high_level_api("%d", a_int) low_level_api("%d", a_int)
high_level_api("a string") low_level_api("a string")
About 400 conversions.
8 special conversions:
VIR_XXXX0("") -> VIR_XXXX("msg") (avoid empty format) 2 conversions
VIR_XXXX0(string_literal_with_%) -> VIR_XXXX(%->%%) 0 conversions
VIR_XXXX0(non_string_literal) -> VIR_XXXX("%s", non_string_literal)
(for security) 6 conversions
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Clang warned about a dead assignment. In the process, I noticed
that we are only using the function for a bool value. I audited
all other callers in qemu_{migration,cgroup,driver,hotplug), and
all were making the call in a bool context.
Also, do bounds checking on the argument.
* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Delete dead
assignment.
(qemuCgroupControllerActive): Change return type to bool.
* src/qemu/qemu_cgroup.h (qemuCgroupControllerActive): Likewise.
It throws errors as long as the cgroup controller is not available,
regardless of whether we really want to use it to do setup or not,
which is not what we want, fixing it with throwing error when need
to use the controller.
And change "VIR_WARN" to "qemuReportError" for memory controller
incidentally.
When domain startup, setting cpu affinity and cpu shares according
to the cputune xml specified in domain xml.
Modify "qemudDomainPinVcpu" to update domain config for vcpupin,
and modify "qemuSetSchedulerParameters" to update domain config
for cpu shares.
v1 - v2:
* Use "VIR_ALLOC_N" instead of "VIR_ALLOC_VAR"
* But keep raising error when it fails on adding vcpupin xml
entry, as I still don't have a better idea yet.
* Correct the documentation for cgroup: the swap_hard_limit indicates
mem+swap_hard_limit.
* Change cgroup private apis to: virCgroupGet/SetMemSwapHardLimit
Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com>
Since libvirt always passes /dev/net/tun to qemu via fd, we should
never trigger the cases where qemu tries to directly open the
device. Therefore, it is safer to deny the cgroup device ACL.
* src/qemu/qemu_cgroup.c (defaultDeviceACL): Remove /dev/net/tun.
* src/qemu/qemu.conf (cgroup_device_acl): Reflect this change.
Adding audit points showed that we were granting too much privilege
to qemu; it should not need any mknod rights to recreate any
devices. On the other hand, lxc should have all device privileges.
The solution is adding a flag parameter.
This also lets us restrict write access to read-only disks.
* src/util/cgroup.h (virCgroup*Device*): Adjust prototypes.
* src/util/cgroup.c (virCgroupAllowDevice)
(virCgroupAllowDeviceMajor, virCgroupAllowDevicePath)
(virCgroupDenyDevice, virCgroupDenyDeviceMajor)
(virCgroupDenyDevicePath): Add parameter.
* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Update clients.
* src/lxc/lxc_controller.c (lxcSetContainerResources): Likewise.
* src/qemu/qemu_cgroup.c: Likewise.
(qemuSetupDiskPathAllow): Also, honor read-only disks.
Device names can be manipulated, so it is better to also log
the major/minor device number corresponding to the cgroup ACL
changes that libvirt made. This required some refactoring
of the relatively new qemu cgroup audit code.
Also, qemuSetupChardevCgroup was only auditing on failure, not success.
* src/qemu/qemu_audit.h (qemuDomainCgroupAudit): Delete.
(qemuAuditCgroup, qemuAuditCgroupMajor, qemuAuditCgroupPath): New
prototypes.
* src/qemu/qemu_audit.c (qemuDomainCgroupAudit): Rename...
(qemuAuditCgroup): ...and drop a parameter.
(qemuAuditCgroupMajor, qemuAuditCgroupPath): New functions, to
allow listing device major/minor in audit.
(qemuAuditGetRdev): New helper function.
* src/qemu/qemu_driver.c (qemudDomainSaveFlag): Adjust callers.
* src/qemu/qemu_cgroup.c (qemuSetupDiskPathAllow)
(qemuSetupHostUsbDeviceCgroup, qemuSetupCgroup)
(qemuTeardownDiskPathDeny): Likewise.
(qemuSetupChardevCgroup): Likewise, fixing missing audit.
When a SPICE or VNC graphics controller is present, and sound is
piggybacked over a channel to the graphics device rather than
directly accessing host hardware, then there is no need to grant
host hardware access to that qemu process.
* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Prevent sound with
spice, and with vnc when vnc_allow_host_audio is 0.
Reported by Daniel Berrange.
Regression in commit caa805ea let a lot of bad messages slip in.
* cfg.mk (msg_gen_function): Fix function name.
* src/qemu/qemu_cgroup.c (qemuRemoveCgroup): Fix fallout from
'make syntax-check'.
* src/qemu/qemu_driver.c (qemudDomainGetInfo)
(qemuDomainWaitForMigrationComplete, qemudStartVMDaemon)
(qemudDomainSaveFlag, qemudDomainAttachDevice)
(qemuDomainUpdateDeviceFlags): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachHostUsbDevice)
(qemuDomainDetachPciDiskDevice, qemuDomainDetachSCSIDiskDevice):
Likewise.
The QEMU driver file is far too large. Move all the cgroup
helper code out into a separate file. No functional change.
* src/qemu/qemu_cgroup.c, src/qemu/qemu_cgroup.h,
src/Makefile.am: Add cgroup helper file
* src/qemu/qemu_driver.c: Delete cgroup code
