Commit Graph

16 Commits

Author SHA1 Message Date
Christophe Fergeau
f5852efa29 log: Make glib logging go through QEMU
This commit adds a error_init() helper which calls
g_log_set_default_handler() so that glib logs (g_log, g_warning, ...)
are handled similarly to other QEMU logs. This means they will get a
timestamp if timestamps are enabled, and they will go through the
HMP monitor if one is configured.

This commit also adds a call to error_init() to the binaries
installed by QEMU. Since error_init() also calls error_set_progname(),
this means that *-linux-user, *-bsd-user and qemu-pr-helper messages
output with error_report, info_report, ... will slightly change: they
will be prefixed by the binary name.

glib debug messages are enabled through G_MESSAGES_DEBUG similarly to
the glib default log handler.

At the moment, this change will mostly impact SPICE logging if your
spice version is >= 0.14.1. With older spice versions, this is not going
to work as expected, but will not have any ill effect, so this call is
not conditional on the SPICE version.

Signed-off-by: Christophe Fergeau <cfergeau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190131164614.19209-3-cfergeau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-04-17 19:08:27 +02:00
John Snow
039d4e3df0 scsi: Address spurious clang warning
Some versions of Clang prior to 6.0 (and some builds of clang after,
such as 6.0.1-2.fc28) fail to recognize { 0 } as a valid initializer
for a struct with subobjects when -Wmissing-braces is enabled.

https://bugs.llvm.org/show_bug.cgi?id=21689 and
https://reviews.llvm.org/rL314499 suggests this should be fixed in 6.0,
but it might not be the case for older versions or downstream versions.

For now, follow the precedent of ebf2a499 and replace the standard { 0 }
with the accepted { } to silence this warning and allow the build to
work under clang 6.0.1-2.fc28, and builds prior to 6.0.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20181127184929.20065-1-jsnow@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-11-27 23:56:12 +00:00
Marc-André Lureau
9e6bdef224 util: add qemu_write_pidfile()
There are variants of qemu_create_pidfile() in qemu-pr-helper and
qemu-ga. Let's have a common implementation in libqemuutil.

The code is initially based from pr-helper write_pidfile(), with
various improvements and suggestions from Daniel Berrangé:

  QEMU will leave the pidfile existing on disk when it exits which
  initially made me think it avoids the deletion race. The app
  managing QEMU, however, may well delete the pidfile after it has
  seen QEMU exit, and even if the app locks the pidfile before
  deleting it, there is still a race.

  eg consider the following sequence

        QEMU 1        libvirtd        QEMU 2

  1.    lock(pidfile)

  2.    exit()

  3.                 open(pidfile)

  4.                 lock(pidfile)

  5.                                  open(pidfile)

  6.                 unlink(pidfile)

  7.                 close(pidfile)

  8.                                  lock(pidfile)

  IOW, at step 8 the new QEMU has successfully acquired the lock, but
  the pidfile no longer exists on disk because it was deleted after
  the original QEMU exited.

  While we could just say no external app should ever delete the
  pidfile, I don't think that is satisfactory as people don't read
  docs, and admins don't like stale pidfiles being left around on
  disk.

  To make this robust, I think we might want to copy libvirt's
  approach to pidfile acquisition which runs in a loop and checks that
  the file on disk /after/ acquiring the lock matches the file that
  was locked. Then we could in fact safely let QEMU delete its own
  pidfiles on clean exit..

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180831145314.14736-2-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02 18:47:55 +02:00
Murilo Opsfelder Araujo
1b0578f5c4 qemu-pr-helper: Fix build on CentOS 7
After commit b3f1c8c413 "qemu-pr-helper: use new
libmultipath API", QEMU started using new libmultipath API, which is not
available on CentOS 7.x.

This fixes that by probing the new libmultipath API in configure.  If it fails,
then try probing the old API.  If it fails, then consider libmultipath not
available.

With this, configure script defines CONFIG_MPATH_NEW_API that is used in
scsi/qemu-pr-helper.c to use the new libmultipath API.

Fixes: b3f1c8c413
BugLink: https://bugs.launchpad.net/qemu/+bug/1786343
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Message-Id: <20180810141116.24016-1-muriloo@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-08-23 13:32:50 +02:00
Michal Privoznik
2729d79d49 pr-helper: Rework socket path handling
When reviewing Paolo's pr-helper patches I've noticed couple of
problems:

1) socket_path needs to be calculated at two different places
(one for printing out help, the other if socket activation is NOT
used),

2) even though the default socket_path is allocated in
compute_default_paths() it is the only default path the function
handles. For instance, pidfile is allocated outside of this
function. And yet again, at different places than 1)

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <c791ba035f26ea957e8f3602e3009b621769b1ba.1530611283.git.mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-06 18:39:19 +02:00
Paolo Bonzini
ee8c13b814 pr-helper: avoid error on PR IN command with zero request size
After reading a PR IN command with zero request size in prh_read_request,
the resp->result field will be uninitialized and the resp.sz field will
be also uninitialized when returning to prh_co_entry.

If resp->result == GOOD (from a previous successful reply or just luck),
then the assert in prh_write_response might not be triggered and
uninitialized response will be sent.

The fix is to remove the whole handling of sz == 0 in prh_co_entry.
Those errors apply only to PR OUT commands and it's perfectly okay to
catch them later in do_pr_out and multipath_pr_out; the check for
too-short parameters in fact doesn't apply in the easy SG_IO case, as
it can be left to the target firmware even.

The result is that prh_read_request does not fail requests anymore and
prh_co_entry becomes simpler.

Reported-by: Dima Stepanov <dimastep@yandex-team.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-06 18:39:19 +02:00
Paolo Bonzini
86933b4e78 pr-helper: fix assertion failure on failed multipath PERSISTENT RESERVE IN
The response size is expected to be zero if the SCSI status is not
"GOOD", but nothing was resetting it.

This can be reproduced simply by "sg_persist -s /dev/sdb" where /dev/sdb
in the guest is a scsi-block device corresponding to a multipath device
on the host.

Before:

  PR in (Read full status): Aborted command

and on the host:

  prh_write_response: Assertion `resp->sz == 0' failed.

After:

  PR in (Read full status): bad field in cdb or parameter list
  (perhaps unsupported service action)

Reported-by: Jiri Belka <jbelka@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-28 19:05:35 +02:00
Paolo Bonzini
50fa332516 pr-helper: fix --socket-path default in help
Currently --help shows "(default '(null)')" for the -k/--socket-path
option.  Fix it by getting the default path in /var/run.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2018-06-28 19:05:34 +02:00
Michal Privoznik
bd6b1c8324 qemu-pr-helper: Write pidfile more often
Let's write pidfile even if user did not request --daemon but
they requested just --pidfile. Libvirt will use exactly this.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-04-09 16:36:40 +02:00
Michal Privoznik
8dc0bf2647 qemu-pr-helper: Daemonize before dropping privileges
After we've dropped privileges it might be not possible to write
pidfile. For instance, if this binary is run as root (because
user wants it to write pidfile to some privileged location)
writing pidfile fails because privileges are dropped before we
even get to that.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-04-09 16:36:40 +02:00
Michal Privoznik
f8e1a98964 qemu-pr-helper: Actually allow users to specify pidfile
Due to wrong specification of arguments to getopt_long() any
attempt to set pidfile resulted in:

1) the default to be leaked
2) the @pidfile variable to be set to NULL (because optarg is
NULL without this patch).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <6f10cd53d361a395aa0e85a9311ec4e9a8fc11e5.1521868451.git.mprivozn@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-26 14:37:15 +02:00
Thomas Huth
7e563bfb8a Polish the version strings containing the package version
Since commit 67a1de0d19 there is no space anymore between the
version number and the parentheses when running configure with
--with-pkgversion=foo :

 $ qemu-system-s390x --version
 QEMU emulator version 2.11.50(foo)

But the space is included when building without that option
when building from a git checkout:

 $ qemu-system-s390x --version
 QEMU emulator version 2.11.50 (v2.11.0-1494-gbec9c64-dirty)

The same confusion exists with the "query-version" QMP command.
Let's fix this by introducing a proper QEMU_FULL_VERSION definition
that includes the space and parentheses, while the QEMU_PKGVERSION
should just cleanly contain the package version string itself.
Note that this also changes the behavior of the "query-version" QMP
command (the space and parentheses are not included there anymore),
but that's supposed to be OK since the strings there are not meant
to be parsed by other tools.

Fixes: 67a1de0d19
Buglink: https://bugs.launchpad.net/qemu/+bug/1673373
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1518692807-25859-1-git-send-email-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-12 16:12:47 +01:00
Paolo Bonzini
a4a9b6eaf3 qemu-pr-helper: miscellaneous fixes
1) Return a generic sense if TEST UNIT READY does not provide one;

2) Fix two mistakes in copying from the spec.

Cc: qemu-stable@nongnu.org
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-12-20 22:29:26 +01:00
Paolo Bonzini
b3f1c8c413 qemu-pr-helper: use new libmultipath API
libmultipath has recently changed its API.  The new API supports multi-threaded
clients better.  Unfortunately there is no backwards-compatibility, so we just
switch to the new one.  Running QEMU compiled with the new library on the old
library will likely crash, while doing the opposite will cause QEMU not to
start at all (because udev, get_multipath_config and put_multipath_config
are undefined).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-10-18 10:15:09 +02:00
Paolo Bonzini
fe8fc5ae5c scsi: add multipath support to qemu-pr-helper
Proper support of persistent reservation for multipath devices requires
communication with the multipath daemon, so that the reservation is
registered and applied when a path comes up.  The device mapper
utilities provide a library to do so; this patch makes qemu-pr-helper.c
detect multipath devices and, when one is found, delegate the operation
to libmpathpersist.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-22 21:07:27 +02:00
Paolo Bonzini
b855f8d175 scsi: build qemu-pr-helper
Introduce a privileged helper to run persistent reservation commands.
This lets virtual machines send persistent reservations without using
CAP_SYS_RAWIO or out-of-tree patches.  The helper uses Unix permissions
and SCM_RIGHTS to restrict access to processes that can access its socket
and prove that they have an open file descriptor for a raw SCSI device.

The next patch will also correct the usage of persistent reservations
with multipath devices.

It would also be possible to support for Linux's IOC_PR_* ioctls in
the future, to support NVMe devices.  For now, however, only SCSI is
supported.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-22 21:07:24 +02:00