Commit Graph

4 Commits

Author SHA1 Message Date
Daniel P. Berrangé
da1ade7a52 remote: remove some __sun conditionals
The libvirtd daemon has some arbitrary logic to drop privileges, but
only on Solaris platforms. This was added during Xen days, when Xen was
the only driver running in libvirtd. There's no expectation or testing
that this works with the new libxl stack, nor whether dropping
privileges breaks any of the secondary drivers. Finally, we'll be
splitting drivers out into their own independant daemons, so this won't
be applicable to libvirtd in future anyway.

The remote driver client meanwhile arbitrarily disables daemon
auto-spawn when connecting as non-root, breaking a key feature of
libvirt unprivileged connections.

Since we've not had any contributions for Solaris since circa 2012
and we don't do any CI testing we should consider this platform
unmaintained and thus reasonable to remove this cruft. If someone steps
forward to maintain Solaris again, this code would need re-evaluating to
come up with something more targetted.

There's various __sun conditionals in the Xen driver code, but those are
not touched. This is all for the legacy Xen driver, which will be
entirely removed at some point in future, so not benefit to hacking out
just the Solaris parts.

Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-03-23 15:10:25 +00:00
Marc Hartmayer
9f24004b82 remote: remove unneeded global variables
Remove unneeded global variables and convert them into local variables
where they're needed.

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>
Reviewed-by: John Ferlan <jferlan@redhat.com>
2018-03-15 17:12:28 -04:00
Jim Fehlig
33c6eb9689 libvirtd: fix potential deadlock when reloading
It is possible to deadlock libvirtd when concurrently starting a domain
and restarting the daemon. Threads involved in the deadlock are

Thread 4 (Thread 0x7fc13b53e700 (LWP 64084)):
/lib64/libpthread.so.0
    at util/virthread.c:154
    at qemu/qemu_monitor.c:1083
    cmd=0x7fc110017700, scm_fd=-1, reply=0x7fc13b53d318) at
qemu/qemu_monitor_json.c:305
cmd=0x7fc110017700,
    reply=0x7fc13b53d318) at qemu/qemu_monitor_json.c:335
    at qemu/qemu_monitor_json.c:1298
    at qemu/qemu_monitor.c:1697
    vm=0x7fc110003d00, asyncJob=QEMU_ASYNC_JOB_START) at qemu/qemu_process.c:1763
vm=0x7fc110003d00,
    asyncJob=6, logCtxt=0x7fc1100089c0) at qemu/qemu_process.c:1835
    vm=0x7fc110003d00, asyncJob=6, logCtxt=0x7fc1100089c0) at
qemu/qemu_process.c:2180
driver=0x7fc12004e1e0,
    vm=0x7fc110003d00, asyncJob=QEMU_ASYNC_JOB_START, incoming=0x0, snapshot=0x0,
    vmop=VIR_NETDEV_VPORT_PROFILE_OP_CREATE, flags=17) at qemu/qemu_process.c:6111
driver=0x7fc12004e1e0,
    vm=0x7fc110003d00, updatedCPU=0x0, asyncJob=QEMU_ASYNC_JOB_START,
migrateFrom=0x0,
    migrateFd=-1, migratePath=0x0, snapshot=0x0,
vmop=VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
    flags=17) at qemu/qemu_process.c:6334
    xml=0x7fc110000ed0 "<!--\nWARNING: THIS IS AN AUTO-GENERATED FILE.
CHANGES TO IT ARE LIKELY TO BE\nOVERWRITTEN AND LOST. Changes to this xml
configuration should be made using:\n  virsh edit testvv\nor other
applicati"..., flags=0) at qemu/qemu_driver.c:1776
...

Thread 1 (Thread 0x7fc143c66880 (LWP 64081)):
/lib64/libpthread.so.0
    at util/virthread.c:122
conf/nwfilter_conf.c:159
sig=0x7ffe0a831e30,
    opaque=0x0) at remote/remote_daemon.c:724
    opaque=0x558c5328b230) at rpc/virnetdaemon.c:654
    at util/vireventpoll.c:508
rpc/virnetdaemon.c:858
remote/remote_daemon.c:1496
(gdb) thr 1
[Switching to thread 1 (Thread 0x7fc143c66880 (LWP 64081))]
/lib64/libpthread.so.0
(gdb) f 1
    at util/virthread.c:122
122	    pthread_rwlock_wrlock(&m->lock);
(gdb) p updateLock
$1 = {lock = {__data = {__lock = 0, __nr_readers = 1, __readers_wakeup = 0,
      __writer_wakeup = 0, __nr_readers_queued = 0, __nr_writers_queued = 1,
__writer = 0,
      __shared = 0, __rwelision = 0 '\000', __pad1 = "\000\000\000\000\000\000",
      __pad2 = 0, __flags = 0},
    __size = "\000\000\000\000\001", '\000' <repeats 15 times>, "\001",
'\000' <repeats 34 times>, __align = 4294967296}}

Reloading of the nwfilter driver is stuck waiting for a write lock, which
already has a reader (from qemuDomainCreateXML) in the critical section.
Since the reload occurs in the context of the main event loop thread,
libvirtd becomes deadlocked. The deadlock can be avoided by offloading
the reload work to a thread.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2018-03-12 10:30:13 -06:00
Daniel P. Berrangé
91fd3dc932 daemon: move libvirtd code into src/remote/ directory
Having a daemon/ directory makes little sense from a code structure
point of view, as 90% of the code that is built into libvirtd already
lives in the src/ directory. The virtlockd and virlogd daemons also live
entirely in src/{locking,logging} directories. This moves the source
code for libvirtd into src/remote/, alongside the client code.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-02-22 12:21:08 +00:00