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
