The qemu shim spawns a separate thread in which the event loop is
ran. The virEventRunDefaultImpl() call is wrapped in a while()
loop, just like it should. There are few lines of code around
which try to ensure that domain is destroyed (when quitting) and
that the last round of event loop is ran after the
virDomainDestroy() call. Only after that the loop is quit from
and the thread quits.
However, if domain creation fails, there is no @dom to call
destroy over, the @quit flag is never set and while() never
exits. Set the flag regardless of @dom pointer.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1920337
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
This problem is reproducible only with secret driver. When
starting a domain via virt-qemu-run and both secret and
(nonexistent) root directory specified this is what happens:
1) virt-qemu-run opens "secret:///embed?root=$rootdir"
connection, which results in the secret driver initialization
(done in secretStateInitialize()). During this process, the
driver creates its own configDir (derived from $rootdir)
including those parents which don't exists yet. This is all
done with the mode S_IRWXU and thus results in the $rootdir
being created with very restrictive mode (specifically, +x is
missing for group and others).
2) now, virt-qemu-run opens "qemu:///embed?root=$rootdir" and
calls virDomainCreateXML(). This results in the master-key.aes
being written somewhere under the $rootdir and telling qemu
where to find it.
But because the secret driver created $rootdir with too
restrictive mode, qemu can't access the file (even though it
knows the full path) and fails to start.
It looks like the best solution is to pre-create the root
directory before opening any connection (letting any driver
initialize itself) and set its mode to something less
restrictive.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1859873
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
The root directory can be provided by user (or a temporary one is
generated) and is always formatted into connection URI for both
secret driver and QEMU driver, like this:
qemu:///embed?root=$root
But if it so happens that there is an URI unfriendly character in
root directory or path to it (say a space) then invalid URI is
formatted which results in unexpected results. We can trust
g_dir_make_tmp() to generate valid URI but we can't trust user.
Escape user provided root directory. Always.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1920400
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
All these headers are indirectly included provided by virfile.h having
virstoragefile.h which will be removed in the following patch.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
This is not expose in most historical versions of glibc, nor
non-glibc impls. We must use our wrapper API instead.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
If a Ctrl-C arrives while we are in the middle of executing the
virDomainCreateXML call, we will have no "virDomainPtr" object
available, but QEMU may none the less be running.
This means we'll never try to stop the QEMU process before we
honour the Ctrl-C and exit.
To deal with this race we need to postpone quit of the event
loop if it is requested while in the middle of domain startup.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
I've found that if my virtlogd is socket activated but the daemon
doesn't run yet, then the virt-qemu-run is killed right after it
tries to start the domain. The problem is that because the default
setting is to use virtlogd, the domain create code tries to
connect to virtlogd socket, which in turn tries to detect who is
connecting (virNetSocketGetUNIXIdentity()) and as a part of it,
it will try to open /proc/${PID_OF_SHIM}/stat which is denied by
SELinux:
type=AVC msg=audit(1582903501.927:323): avc: denied { search } for \
pid=1210 comm="virtlogd" name="1843" dev="proc" ino=37224 \
scontext=system_u:system_r:virtlogd_t:s0-s0:c0.c1023 \
tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=dir \
permissive=0
Virtlogd reacts by closing the connection which the shim sees as
SIGPIPE. Since the default response to the signal is Term, we
don't even get to reporting any error nor to removing the
temporary directory.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
When virt-qemu-run is ran without any root directory specified on
the command line, a temporary directory is made and used instead.
But since we are using g_dir_make_tmp() to create the directory
it is going to have 0700 mode. So even though we create the whole
directory structure under it and label everything, QEMU is very
likely to not have the access. This is because in this case there
is no qemu.conf and thus distro default UID:GID is used to run
QEMU (e.g. qemu:kvm on Fedora). Change the mode of the temporary
directory so that everybody has eXecute permission.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Include virutil.h in all files that use it,
instead of relying on it being pulled in somehow.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The template still references libvirt-qemu-shim, which was at one
point the name used to refer to what we now know as virt-qemu-run.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Remove bogus G_GNUC_UNUSED attribute and add a missing space.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Fixes: d600667278
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
The previous "QEMU shim" proof of concept was taking an approach of only
caring about initial spawning of the QEMU process. It was then
registered with the libvirtd daemon who took over management of it. The
intent was that later libvirtd would be refactored so that the shim
retained control over the QEMU monitor and libvirt just forwarded APIs
to each shim as needed. This forwarding of APIs would require quite alot
of significant refactoring of libvirtd to achieve.
This impl thus takes a quite different approach, explicitly deciding to
keep the VMs completely separate from those seen & managed by libvirtd.
Instead it uses the new "qemu:///embed" URI scheme to embed the entire
QEMU driver in the shim, running with a custom root directory.
Once the driver is initialization, the shim starts a VM and then waits
to shutdown automatically when QEMU shuts down, or should kill QEMU if
it is terminated itself. This ought to use the AUTO_DESTROY feature but
that is not yet available in embedded mode, so we rely on installing a
few signal handlers to gracefully kill QEMU. This isn't reliable if
we crash of course, but you can restart with the same root dir.
Note this program does not expose any way to manage the QEMU process,
since there's no RPC interface enabled. It merely starts the VM and
cleans up when the guest shuts down at the end. This program is
installed to /usr/bin/virt-qemu-run enabling direct use by end users.
Most use cases will probably want to integrate the concept directly
into their respective application codebases. This standalone binary
serves as a nice demo though, and also provides a way to measure
performance of the startup process quite simply.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
