Commit Graph
100 Commits
Author SHA1 Message Date
Daniel P. Berrangé b8a3ed957e qemu: lookup node device against nodedev driver before getting XML
Some of the node device APIs are a little odd because they accept a
virNodeDevicePtr object but are still implemented by the virt drivers.
The first thing the virt drivers need to do is get the XML config
associated with the node device, and that means talking to the node
device driver.

This worked previously because with monolithic libvirtd, both the
virt driver and node device driver were in the same daemon and thus
a single virConnectPtr can talk to both drivers.

With the split daemon world though, the virNodeDevicePtr passed into
the APIs is associated with the QEMU driver virConnectPtr, which has
no ability to invoke APIs against the node device driver. We must thus
get a duplicate virNodeDevicePtr object which is associated with a
virConnectPtr for the node device driver.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-17 13:58:20 +00:00
Daniel P. Berrangé 69eee587da rpc: avoid name lookup when dispatching node device APIs
The node device APIs are a little unusual because we don't use a
"remote_nonnull_node_device" object on the wire, instead we just
have a "remote_string" for the device name. This meant dispatcher
code generation needed special cases. In doing so we mistakenly
used the virNodeDeviceLookupByName() API which gets dispatched
into the driver, instead of get_nonnull_node_device() which
directly populates a virNodeDevicePtr object.

This wasn't a problem with monolithic libvirtd, as the
virNodeDeviceLookupByName() API call was trivially satisfied
by the registered driver, albeit with an extra (undesirable)
authentication check. With the split daemons, the call to
virNodeDeviceLookupByName() fails in virtqemud, because the
node device driver obviously doesn't exist in that daemon.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-17 13:58:20 +00:00
Daniel P. Berrangé 744208e7db rpc: fix dispatch for node device APIs for virt drivers
Despite their names, the following APIs:

    virNodeDeviceDettach
    virNodeDeviceDetachFlags
    virNodeDeviceReAttach
    virNodeDeviceReset

are all handled by the virt drivers, not the node device driver.
A bug in the RPC generator meant that these APIs were sent to
the nodedev driver for handling. This caused breakage with the
split daemons, since nothing was available to process them.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-17 13:58:20 +00:00
Daniel P. Berrangé 008abeb03c nodedev: fix race in API usage vs initial device enumeration
During startup the udev node device driver impl uses a background thread
to populate the list of devices to avoid blocking the daemon startup
entirely. There is no synchronization to the public APIs, so it is
possible for an application to start calling APIs before the device
initialization is complete.

This was not a problem in the old approach where libvirtd was started
on boot, as initialization would easily complete before any APIs were
called.

With the use of socket activation, however, APIs are invoked from the
very moment the daemon starts. This is easily seen by doing a

  'virsh -c nodedev:///system list'

the first time it runs it will only show one or two devices. The second
time it runs it will show all devices. The solution is to introduce a
flag and condition variable for APIs to synchronize against before
returning any data.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-16 17:35:04 +00:00
Daniel P. Berrangé c34b8cbf1c tests: validate parsing of CPUs with dies > 1
Add sample data files for validating handling of a QEMU guest started
with:

  -smp 7,maxcpus=16,sockets=2,dies=2,cores=2,threads=2

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-16 16:00:27 +00:00
Daniel P. Berrangé 8b789c6574 qemu: fix detection of vCPU pids when multiple dies are present
The logic for querying hotpluggable CPUs needs to sort the list
of CPUs returned by QEMU. Unfortunately our sorting method failed
to use the die_id field, so CPUs were not correctly sorted.

This is seen when configuring a guest with partially populated
CPUs

  <vcpu placement='static' current='1'>16</vcpu>
  <cpu...>
    <topology sockets='4' dies='2' cores='1' threads='2'/>
  </cpu>

Then trying to start it would fail:

  # virsh -c qemu:///system start demo
  error: Failed to start domain demo
  error: internal error: qemu didn't report thread id for vcpu '0'

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-16 16:00:27 +00:00
Daniel P. Berrangé fdd941eeb2 build: workaround behaviour regression in gnu make 4.3
We need the "$(space)" variable to contain a single whitespace
character. We do this by assigning and then appending an empty
string to the variable. Variable appends get separated by a
single whitespace historically, but GNU make 4.3 introduced a
behaviour regression.

  https://lists.gnu.org/archive/html/bug-make/2020-01/msg00057.html

[quote]
* WARNING: Backward-incompatibility!
  Previously appending using '+=' to an empty variable would
  result in a value starting with a space.  Now the initial
  space is only added if the variable already contains some
  value.  Similarly, appending an empty string does not
  add a trailing space.
[/quote]

This patch tries a new trick to get a single whitespace by
getting make to expand two non-existant variables separated
by a space.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-16 12:07:21 +00:00
Daniel P. Berrangé 0a815baf2f util: ensure min/maj are initialized in virGetDeviceID
The stub impl of virGetDeviceID just returns ENOSYS and does not
initialize the min/maj output parameters. This lead to a false
positive warning on mingw about possible use of uninitialized
variables.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-13 11:28:31 +00:00
Daniel P. Berrangé 46e16b553d tests: fix double unlock of monitor in hotplug test
The qemuMonitorTestNew() function returns with the monitor object
locked, and expects it to still be locked when qemuMonitorTestFree
is called.  The qemuhotplug test, however, explicitly unlocks the
monitor, but then forgets to lock it again. As a result the
qemuMonitorTestFree function is unlocking a mutex it doesn't own.

This bug has existed forever, but since we use normal POSIX mutexes
and don't check the return value of pthread_mutex_lock/unlock we
didn't see the error. It was harmless until the switch to the per
monitor event loop which requires the thread synchronization to
work reliably, whereupon it started crashing.

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-13 11:27:57 +00:00
Daniel P. Berrangé a18f2c52ac qemu: convert agent to use the per-VM event loop
This converts the QEMU agent APIs to use the per-VM
event loop, which involves switching from virEvent APIs
to GMainContext / GSource APIs.

A GSocket is used as a convenient way to create a GSource
for a socket, but is not yet used for actual I/O.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:45:01 +00:00
Daniel P. Berrangé 0d62faf62a qemu: fix variable naming in agent code
We are dealing with the QEMU agent, not the monitor.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:44:58 +00:00
Daniel P. Berrangé 436a56e37d qemu: convert monitor to use the per-VM event loop
This converts the QEMU monitor APIs to use the per-VM
event loop, which involves switching from virEvent APIs
to GMainContext / GSource APIs.

A GSocket is used as a convenient way to create a GSource
for a socket, but is not yet used for actual I/O.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:44:55 +00:00
Daniel P. Berrangé ba906ab1c0 tests: start/stop an event thread for QEMU monitor/agent tests
Tests which are using the QEMU monitor / agent need to have an
event thread running a private GMainContext.

There is already a thread running the main libvirt event loop
but this can't be eliminated yet as it is used for more than
just the monitor client I/O.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:44:51 +00:00
Daniel P. Berrangé 92890fbfa1 qemu: start/stop an event thread for QMP probing
In common with regular QEMU guests, the QMP probing
will need an event loop for handling monitor I/O
operations.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:44:47 +00:00
Daniel P. Berrangé e6afacb0fe qemu: start/stop an event loop thread for domains
The event loop thread will be responsible for handling
any per-domain I/O operations, most notably the QEMU
monitor and agent sockets.

We start this event loop when launching QEMU, but stopping
the event loop is a little more complicated. The obvious
idea is to stop it in qemuProcessStop(), but if we do that
we risk loosing the final events from the QEMU monitor, as
they might not have been read by the event thread at the
time we tell the thread to stop.

The solution is to delay shutdown of the event thread until
we have seen EOF from the QEMU monitor, and thus we know
there are no further events to process.

Note that this assumes that we don't have events to process
from the QEMU agent.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:44:44 +00:00
Daniel P. Berrangé 5c146f6e57 src: introduce an abstraction for running event loops
We want a way to easily run a private GMainContext in a
thread, with correct synchronization between startup
and shutdown of the thread.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-11 14:44:04 +00:00
Daniel P. Berrangé 415e022118 src: fix mixup of stack and heap allocated data in auth callback
In the following recent change:

  commit db72866310
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Tue Jan 14 10:40:52 2020 +0000

    util: add API for reading password from the console

the fact that "bufptr" pointer may point to either heap or stack
allocated data was overlooked. As a result, when the strdup was
removed, we ended up returning a pointer to the local stack to
the caller. When the caller referenced this stack pointer they
got out garbage which fairly quickly resulted in a crash.

We need to copy the stack buffer into heap memory in the username
case.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-06 17:02:10 +00:00
Daniel P. Berrangé 579f02351b test: fix leak of authentication info
The 'auths' struct in the test driver was not free()d. This was easy to
miss because the default XML doesn't include auth info.

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-06 13:18:16 +00:00
Daniel P. Berrangé 4f77a9c629 docs: add page describing the libvirt daemons
Now that we have more than just the libvirtd daemon, we should be
explaining to users what they are all for & important aspects of their
configuration.

Reviewed-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-05 15:40:01 +00:00
Daniel P. Berrangé 71ebda3af1 src: add pthread_np.h include for FreeBSD
On FreeBSD the non-portable pthread APIs need to be obtained
via the pthread_np.h header.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-05 15:13:45 +00:00
Daniel P. Berrangé 5bff668dfb src: improve thread naming with human targetted names
Historically threads are given a name based on the C function,
and this name is just used inside libvirt. With OS level thread
naming this name is now visible to debuggers, but also has to
fit in 15 characters on Linux, so function names are too long
in some cases.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-05 12:23:04 +00:00
Daniel P. Berrangé c85256b31b src: set the OS level thread name
Setting the thread name makes it easier to debug libvirtd
when many threads are running.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-05 12:23:02 +00:00
Daniel P. Berrangé eab55b2534 qemu: drop ability to open monitor from FD
The qemuMonitorOpenFD method has not been used since it
was first introduced.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-05 12:22:59 +00:00
Daniel P. Berrangé 78f66a12ea qemu: drop support for agent connections on PTYs
Libvirt has never configured the QEMU agent to support
running on a PTY implicitly. In theory an end user may
have written such an XML config, but this is reasonably
unlikely since when a bare <channel> is provided, libvirt
will auto-expand it to a UNIX socket backend.

With this change a user who has use the PTY backend will
have to switch to the UNIX backend if they wish to use
libvirt APIs for interacting with the agent. This will
not have guest ABI impact.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-03-05 12:22:52 +00:00
Daniel P. Berrangé 9033104939 docs: fix docs about bandwidth setting with bridge networks
We now support setting bandwidth on networks with type bridge.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-26 16:05:04 +00:00
Daniel P. Berrangé 386dfa7c7b tests: fix missing test data for network port XML
The network port XML files were not including any usage of vlan
tags or port options, and one of the files was not even processed.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-25 15:43:56 +00:00
Daniel P. Berrangé 6a38acb3c0 src: add virutil.h to more source files for geteuid() compat
The virutil.h header defines a geteuid() macro for Windows platforms.
This fixes a few missed cases from:

  commit b11e8cccdd
  Author: Ján Tomko <jtomko@redhat.com>
  Date:   Sun Feb 16 23:09:15 2020 +0100

    Remove virutil.h from all header files

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-25 10:02:15 +00:00
Daniel P. Berrangé 6eb9bb9cf1 build: stop running aclocal manually
The autoreconf script will already run aclocal for us,
so there's no need to do that ahead of time.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-25 09:22:56 +00:00
Daniel P. Berrangé 958d6ebe53 docs: add a kbase explaining security protections for QEMU passthrough
When using command line passthrough users will often trip up over the
security protections like SELinux, DAC, namespaces, etc which will
deny access to files they are passing. This document explains the
various protections and how to deal with their policy, and/or how
to disable them.

Reviewed-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-24 12:52:24 +00:00
Daniel P. Berrangé b2aec51686 docs: add news item about gnulib removal
While we have CI testing coverage for many platforms, we don't test any
non-glibc based Linux and there are other non-Linux platforms we don't
officially target, both of which might hit regressions.

Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-24 11:36:02 +00:00
Daniel P. Berrangé 4be5a2f0c2 docs: reduce excessive spacing in ToC for RST files
The table of contents in the RST based files uses <p> tags inside the
<li>, which results in 1em's worth of spacing above & below each
entry. This results in way too much whitespace in the ToC.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-24 11:34:15 +00:00
Daniel P. Berrangé 9b82e2c4b0 qemu: drop support for monitor connections on PTYs
Libvirt switched to using a UNIX socket for monitors in
2009 for version 0.7.0. It seems unlikely that there is
a running QEMU process that hasn't been restarted for
11 years while also taking a libvirt upgrade. Therefore
we can drop support for opening a PTY for the QEMU
monitor.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-13 12:52:07 +00:00
Daniel P. Berrangé 2621d48f00 gnulib: delete all gnulib integration
This deletes all trace of gnulib from libvirt. We still
have the keycodemapdb submodule to deal with. The simple
solution taken was to update it when running autogen.sh.

Previously gnulib could auto-trigger refresh when running
'make' too. We could figure out a solution for this, but
with the pending meson rewrite it isn't worth worrying
about, given how infrequently keycodemapdb changes.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:54 +00:00
Daniel P. Berrangé 55fe8110af util: delete the poll() based event loop impl
It is no longer require since switching to the GLib based
event loop impl.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:54 +00:00
Daniel P. Berrangé 946a25274c util: switch to use the GLib event loop impl
This sets the GLib event loop as the impl when calling
virEventRegisterDefaultImpl(). This remains a private
impl detail of libvirt, so applications must *NOT*
assume that a call to virEventRegisterDefaultImpl()
results in a GLib based event loop.

They should continue to use the libvirt-glib API
gvir_event_register() if they explicitly want to guarantee
a GLib event loop.

This follows the general principal that the libvirt public
API should not expose the fact that GLib is being used
internally.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:53 +00:00
Daniel P. Berrangé f8ab47cb44 util: import an event loop impl based on GMainContext
The libvirt-glib project has provided a GMainContext based
event loop impl for applications. This imports it and sets
it up for use by libvirt as the primary event loop. This
remains a private impl detail of libvirt.

IOW, applications must *NOT* assume that a call to
"virEventRegisterDefaultImpl" results in a GLib based
event loop. They should continue to use the libvirt-glib
API gvir_event_register() if they explicitly want to
guarantee a GLib event loop.

This follows the general principle that the libvirt public
API should not expose the fact that GLib is being used
internally.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:53 +00:00
Daniel P. Berrangé 7d4350bcac rpc: convert RPC client to use GMainLoop instead of poll
To eliminate the dependancy on GNULIB's poll impl, we need
to change the RPC client code to use GMainLoop. We don't
really want to use GIOChannel, but it provides the most
convenient way to do socket event watches with Windows
portability. The other alternative would be to use GSocket
but that is a much more complex change affecting libvirt
more broadly.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:53 +00:00
Daniel P. Berrangé 5de317b8e7 src: introduce helper API for creating GSource for socket
We need to be able to create event loop watches using the
GSource API for sockets. GIOChannel is able todo this, but
we don't want to use the GIOChannel APIs for reading/writing,
and testing shows just using its GSource APIs is unreliable
on Windows.

This patch thus creates a standalone helper API for creating
a GSource for a socket file descriptor. This impl is derived
from code in QEMU's io/channel-watch.c file that was written
by myself & Paolo Bonzini & thus under Red Hat copyright.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:53 +00:00
Daniel P. Berrangé dc0771cfa2 tools: rewrite interactive job monitoring logic
For long running jobs (save, managed save, dump & live migrate)
virsh runs a background thread for executing the job and then
has the main thread catch Ctrl-C for graceful shutdown, as well
as displaying progress info.

The monitoring code is written using poll, with a pipe used
to get the completion status from the thread. Using a pipe
and poll is problematic for Windows portability. This rewrites
the code to use a GMainLoop instance for monitoring stdin and
doing progress updates. The use of a pipe is entirely eliminated,
instead there is just a shared variable between both threads
containing the job completion status.

No mutex locking is used because the background thread writes
to the variable only when the main loop is still running,
while the foreground thread only reads it after the main loop
has exited.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 15:03:53 +00:00
Daniel P. Berrangé 29c4a3c753 tests: avoid referencing stale readdir pointer
The contents of 'struct dirent' are only valid until the next call to
readdir() or closedir(). It is thus invalid to save a pointer to the
'd_name' field. Somehow this hasn't affected the test suite until
recently when FreeBSD 12 started showing use of uninitialized memory
resulting in test failures.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 14:57:59 +00:00
Daniel P. Berrangé 039787c71a docs: render class="literal" with monospace font
When using ``....`` in RST, this results in <span class="literal">...</span>
instead of <code>...</code>. We thus need an extra rule to render it
with a monospace font. Colouring a light gray also helps the text
stand out a little more and matches background of <pre> blocks.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-07 10:18:16 +00:00
Daniel P. Berrangé 4ab2120f3b src: remove virFilePrintf in favour of g_fprintf
The virFilePrintf function was a wrapper for fprintf() to provide
Windows portability, since gnulib's fprintf() replacement was
license restricted. This is no longer needed now we have the
g_fprintf function available.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé 11a79283b8 src: ensure use of g_printf / g_fprintf functions
The printf/fprintf function impls provided on Windows do
not follow the normal syntax for format specifiers as
the UNIX hosts. Currently we use GNULIB to provide a
portability fix for this. GLib has also imported the
GNULIB impl for this same reason, and thus we can rely
on the g_printf / g_fprintf functions.

This identified a couple of places not explicitly
linking to glib.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé b9103e62e4 src: optionally include xlocale.h header
On macOS some definitions are in xlocale.h, instead of in
locale.h. GNULIB hides this difference by making the latter
include the former.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé 262551f774 src: add define of ENOMSG for MinGW
MinGW lacks ENOMSG until version 6.0.0 (Fedora 31).

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé 03c532cf97 src: assume sys/sysmacros.h always exists on Linux
All our supported Linux distros now have this header.
It has never existed on FreeBSD / macOS / Mingw.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé f691ec63b4 m4: add check for pthread library
When we get rid of GNULIB, we need to check for -lpthread
support.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé c7aac54bc1 tools: conditionalize use of O_SYNC flag
The O_SYNC flag is not defined on Windows platforms.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:45 +00:00
Daniel P. Berrangé cc46e137eb src: convert code to use virPipe APIs
This addreses portability to Windows and standardizes
error reporting. This fixes a number of places which
failed to set O_CLOEXEC or failed to report errors.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé ab36f72947 src: introduce a wrapper for the pipe2() system call
This hides the differences between Windows and UNIX,
and adds standard error reporting.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé 4d61dd5abf examples: remove obsolete workaround for mingw
The build still succeeds with the workaround removed, so
whatever was causing the problem no longer exists.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé 7c8b144d4a configure: request 64-bit APIs on 32-bit platforms
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé bfeb56b3ad src: remove sys/wait.h from many files
Most code now uses the virProcess / virCommand APIs, so
the need for sys/wait.h is quite limited. Removing this
include removes the dependency on GNULIB providing a
dummy sys/wait.h for Windows.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé aa52947fc6 util: conditionalize FD stream to exclude WIN32
Almost none of the virFDStream code will actually work
on WIN32 builds, nor is it used except for in the
virtualbox driver for screenshots. It is simpler to
wrap it all in a '#ifndef WIN32'.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé 7aef7cdbb5 src: conditionalize / remove use of poll.h
Remove imports of poll.h which are redundant, and
conditionalize remaining usage that needs to compile
on Windows platforms.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé 32363452af tests: refactor event test to not run lock step
The current event loop test suite has two threads running
in lockstep. This was just about viable when we have full
control over the internal details of the event loop impl.
When we're using the GLib event loop though there are
things going on that we don't know about, such as use of
eventfd() file descriptors. This will break the assumptions
in the test suite, causing non-deterministic failures.

This change switches the event loop thread to run fully
asynchronously from the test suite cases. This is slightly
weaker validation, but the only way we can get a reliable
test suite.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé abab604e30 tests: remove event loop from command test
This effectively reverts

  commit 39c77fe586
  Author: Michal Prívozník <mprivozn@redhat.com>
  Date:   Wed Jan 16 11:58:00 2013 +0100

    Introduce event loop to commandtest

because nothing in the current test suite needs this
event loop.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé 194382c183 tests: convert eventtest to use public event APIs
The event test directly calls the internal poll event impl
APIs. It does not rely on any specific details of the poll
impl, so it is better to use the public APIs.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-02-04 14:00:44 +00:00
Daniel P. Berrangé 3d63a187ba bootstrap: remove 18 more gnulib modules
* chown: use is conditionally compiled
* configmake: functionality imported to Makefile.am
* getaddrinfo: we have no portability problems
  with Windows impl
* getpass: simplified impl is imported
* mgetgroups: getgrouplist is used directly
* net_if: header includes are conditionalized
* netdb: header includes are conditionalized
* passfd: simplified impl is imported
* posix-shell: functionality was unused & removed
* sigaction: usage is conditionalized
* sigpipe: usage is conditionalized
* stat-time: struct stat is used directly
* strchrnul: usage is eliminated
* strtok_r: usage is not a portability problem
* sys_stat: usage is conditionalized
* uname: rewritten to use native Win32 function to
  get host arch
* waitpid: usage is conditionalized
* wcwidth: rewritten using g_unichar APIs

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé e429934550 src: conditionalize EAI_ADDRFAMILY
The EAI_ADDRFAMILY constant has been removed from FreeBSD
headers, supposedly because it is deprecated by new RFC
drafts.

Previously GNULIB was providing a replacement because
MinGW lacked it too. The replacement provided for MinGW
was thus being used on FreeBSD too, but with a completely
bogus integer value.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 21fa70e2f6 tests: conditionalize use of SIGPIPE
SIGPIPE is not available on the Windows platform.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé fc920f704c src: convert all code to use virsocket.h
There are a large number of different header files that
are related to the sockets APIs. The virsocket.h header
includes all of the relevant headers for Windows and UNIX
in one convenient place. If virsocketaddr.h is already
included, then there's no need for virsocket.h

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé a464220430 src: conditionalize use of chown & stat constants
chown and some stat constants are not available on
the Windows platform.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 6dd8913207 src: conditionalize use of O_BINARY
The O_BINARY flag is not defined on all platforms so we must
conditionalize its use once we remove GNULIB.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé b0bea258d3 src: conditionalize use of O_DIRECT
The O_DIRECT flag is not available on all platforms, so we
must introduce a compat define the same way gnulib does.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 4b9919af40 src: conditionalize use of F_DUPFD_CLOEXEC
The F_DUPFD_CLOEXEC functionality is not available on
some platformms. We must thus explicitly call the
virSetCloexec function once we remove GNULIB's equiv
fix for this.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 2a656fc9d8 src: ensure O_CLOEXEC is defined on Windows
Windows uses _O_NOINHERIT as the name for its O_CLOEXEC
equivalent. Define O_CLOEXEC to match this to fix
portability when we remove GNULIB.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 18dca21a32 src: stop using O_DIRECTORY in resctrl
The O_DIRECTORY flag causes open() to return an error
if the filename is a directory. There's no obvious
reason why resctrl needs to use this, while the rest of
libvirt code does not. Removing it avoids build issues
on platforms where O_DIRECTORY is not defined, once we
remove GNULIB.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 5c455d9081 configure: request system specific extensions
The AC_USE_SYSTEM_EXTENSIONS macro causes things like
"USE_GNU" to be defined, which enables access to OS
specific extensions to POSIX. We currently got this
indirectly via GNULIB's 'extensions' module which is
a dependancy of other GNULIB modules we use.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 3ec271bada src: conditionalize use of S_ISSOCK macro
The S_ISSOCK macro is not available on Windows platforms.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé cf308f13db configure: add check for sys/ioctl.h
We currently get the sys/ioctl.h check indirectly
via GNULIB, but this will soon stop happening.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 7f3eb533f4 src: conditionalize use of net/if.h
The net/if.h is not portable so we must check for its
existance and avoid using it when missing. Some use
of net/if.h was redundant and could be removed.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 2b45f453a3 util: conditionalize virProcess APIs on Windows
Many of the virProcess APIs are relying on GNULIB providing
POSIX API stubs. Even with these stubs the APIs don't do
anything useful once compiled. We can thus conditionalize
the code so that we don't compile anything at all.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 32fe38646a src: remove all traces of Cygwin support
Cygwin is not a supported build platform for libvirt and
has no testing coverage in our CI systems. Stop pretending
the code is usable and remove it so there is less to port
to Meson.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 19ae64653d util: conditionalize more of virCommand on WIN32
A large part of the virCommand code is still built on
WIN32, despite the fact that the core fork() & execve()
functions are not available. So despite succesfully
building most of the code, at runtime the APIs are
none the less unusuable. With the elimination of GNULIB
many of the APIs being used in this code no longer have
portability wrappers/shims for Windows.

Rather than try to add portability wrappers, or do tests
for each individual function, it is clearer to conditionalize
nearly all of the code using #ifdef WIN32.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé c7df5ca0bb m4: disable polkit build on Windows
polkit is only useful on Linux systems

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé c58edd05f7 src: replace mkdir() with g_mkdir()
g_mkdir() provides portability to Windows platforms.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 3aab3362f6 src: only import sys/uio.h when journald is built
The sys/uio.h header is only needed when building logging
code with journald support enabled. Conditionally include
it so that we avoid break on platforms which lack this
header.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé ff627b4726 rpc: conditionalize signal handling
The Windows platform does not have the signal handling
support we need, so it must be disabled in several parts
of the codebase.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:40 +00:00
Daniel P. Berrangé 17460825f3 src: implement APIs for passing FDs over UNIX sockets
This is a simplified variant of gnulib's passfd module
without the portability code that we do not require.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé d575590c52 storage: remove use of stat-time.h headers
The gnulib stat-time.h header provides wrapper functions
to hide the differences in 'struct stat' between various
platforms.

Linux and FreeBSD support the same names, except for
birthtime which Linux only provides in the new 'statx()'
syscall we're not using. macOS has completely different
naming. Since we only rely on this code in one place
we just use conditionals at time of need.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 47744e0694 util: explicitly include windows.h
The virProcess code relies on windows.h and is getting it
indirectly via some GNULIB header fixes. This dependancy
needs to be made explicit.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 3f4435d877 src: remove unused sys/utsname.h includes
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 6485c2c0ae tools: replace wcwidth() with g_unichar_* APIs
The combination of g_unichar_iszerowidth and
g_unichar_iswide is sufficient to replicate the logic
of wcwidth() for libvirt.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 540cf03926 util: use getgrouplist() directly instead of mgetgroups
The mgetgroups function is a GNULIB custom wrapper around
getgrouplist(). This implements a simplified version of
that code directly.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé f80c009cb3 build: generate configmake.h in root directory
Currently we rely on gnulib creating configmake.h, but we
can easily create it ourselves instead.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 27a6edf50f src: remove usage of strchrnul function
The strchrnul function doesn't exist on Windows and rather
than attempt to implement it, it is simpler to just avoid
its usage, as any callers are easily adapted.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé db72866310 util: add API for reading password from the console
This imports a simpler version of GNULIB's getpass() function
impl for Windows. Note that GNULIB's impl was buggy as it
returned a static string on UNIX, and a heap allocated string
on Windows. This new impl always heap allocates.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 19ff90a9c5 util: add a virArchFromHost() impl for Windows
Instead of relying on GNULIb's uname() impl, directly use the
Windows API for determining CPU architecture.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé e7def90b90 tests: stop setting $SHELL env variable
None of the tests appear to reference a SHELL env variable
explicitly and they all succeeed when it is not set. This
eliminates the only use of the gnulib posix-shell module.

Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:51:39 +00:00
Daniel P. Berrangé 217b564a77 docs: add warning about virt-qemu-run being experimental
We currently note that the QEMU embedded driver is experimental
in the drvqemu.html file, but we should do the same in the
virt-qemu-run man page.

Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 14:30:57 +00:00
Daniel P. Berrangé 5b971b0f76 docs: use --strict arg when processing rst docs
The --strict arg forces the rst tools to abort with an error instead
of printing warnings to stderr, or the output document.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 12:16:13 +00:00
Daniel P. Berrangé 4ed55c0be1 docs: fix various duplicate link targets in virsh.rst
You can't have two links with the same text when using named
link references (a single "_"). If you need multiple links
with the same text you must use anonymous link references
(a double "_").

There are also some duplicate section headers causing the
same problem with duplicate link targets.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 12:16:00 +00:00
Daniel P. Berrangé 82dd011dbb qemu: fix linking virt-qemu-run on some distros
Debian/Ubuntu linkers are more strict that other distros requiring glib
to be linked explicitly.

macOS needs -export-dynamic instead of -Wl,--export-dynamic

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 13:44:56 +00:00
Daniel P. Berrangé 9a5bafd329 bhyve: add 'root' parameter to driver initializer
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 13:44:56 +00:00
Daniel P. Berrangé 201156ec6e docs: add pages to support Go module package resolution
Currently the libvirt Go modules are accessed by applications using
their github repository URLs. This is undesirable as we don't want
applications to have a direct dependancy on a specific source repo
location. We want to enable applications to use the Go packages via
the libvirt.org namespace.

When you do "go get libvirt.org/libvirt-go", the Go client will do an
HTTPS request to that URL, and parse the HTML content to look for a
<meta> tag which tells it where to the find the GIT repository.

   https://golang.org/cmd/go/#hdr-Remote_import_paths

This adds two pages to support this Go module resolution. They are
not linked from anywhere as we don't expect users to actually look
at them. If someone does happen upon them, there's some boilerplate
text to send them off to godoc.org for API documentation.

Since the pages we're adding have a .html extension, we will also
use a small apache config tweak on the server

    RewriteEngine on
    RewriteRule ^/libvirt-go$ /libvirt-go.html [L]
    RewriteRule ^/libvirt-go-xml$ /libvirt-go-xml.html [L]

Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 11:51:46 +00:00
Daniel P. Berrangé d600667278 qemu: introduce a new "virt-qemu-run" program
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>
2020-01-27 11:05:02 +00:00
Daniel P. Berrangé 3e9076e777 secrets: add support for running secret driver in embedded mode
This enables support for running the secret driver embedded to the
calling application process using a URI:

   secret:///embed?root=/some/path

When using the embedded mode with a root=/var/tmp/embed, the
driver will use the following paths:

       configDir: /var/tmp/embed/etc/secrets
        stateDir: /var/tmp/embed/run/secrets

These are identical whether the embedded driver is privileged
or unprivileged.

This compares with the system instance which uses

       configDir: /etc/libvirt/secrets
        stateDir: /var/lib/libvirt/secrets

When an embedded instance of the secret driver is open, any other
embedded drivers will automatically use the embedded secret driver.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 11:04:29 +00:00
Daniel P. Berrangé 068efae5b1 qemu: add support for running QEMU driver in embedded mode
This enables support for running QEMU embedded to the calling
application process using a URI:

   qemu:///embed?root=/some/path

Note that it is important to keep the path reasonably short to
avoid risk of hitting the limit on UNIX socket path names
which is 108 characters.

When using the embedded mode with a root=/var/tmp/embed, the
driver will use the following paths:

                logDir: /var/tmp/embed/log/qemu
           swtpmLogDir: /var/tmp/embed/log/swtpm
         configBaseDir: /var/tmp/embed/etc/qemu
              stateDir: /var/tmp/embed/run/qemu
         swtpmStateDir: /var/tmp/embed/run/swtpm
              cacheDir: /var/tmp/embed/cache/qemu
                libDir: /var/tmp/embed/lib/qemu
       swtpmStorageDir: /var/tmp/embed/lib/swtpm
 defaultTLSx509certdir: /var/tmp/embed/etc/pki/qemu

These are identical whether the embedded driver is privileged
or unprivileged.

This compares with the system instance which uses

                logDir: /var/log/libvirt/qemu
           swtpmLogDir: /var/log/swtpm/libvirt/qemu
         configBaseDir: /etc/libvirt/qemu
              stateDir: /run/libvirt/qemu
         swtpmStateDir: /run/libvirt/qemu/swtpm
              cacheDir: /var/cache/libvirt/qemu
                libDir: /var/lib/libvirt/qemu
       swtpmStorageDir: /var/lib/libvirt/swtpm
 defaultTLSx509certdir: /etc/pki/qemu

At this time all features present in the QEMU driver are available when
running in embedded mode, availability matching whether the embedded
driver is privileged or unprivileged.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 11:04:03 +00:00
Daniel P. Berrangé 88446e07b2 libvirt: support an "embed" URI path selector for opening drivers
The driver URI scheme:

  "$drivername:///embed?root=/some/path"

enables a new way to use the drivers by embedding them directly in the
calling process. To use this the process must have a thread running the
libvirt event loop. This URI will then cause libvirt to dynamically load
the driver module and call its global initialization function. This
syntax is applicable to any driver, but only those will have been
modified to support a custom root directory and embed URI path will
successfully open.

The application can now make normal libvirt API calls which are all
serviced in-process with no RPC layer involved.

It is required to specify an explicit root directory, and locks will be
acquired on this directory to avoid conflicting with another app that
might accidentally pick the same directory.

Use of '/' is not explicitly forbidden, but note that the file layout
used underneath the embedded driver root does not match the file
layout used by system/session mode drivers. So this cannot be used as
a backdoor to interact with, or fake, the system/session mode drivers.

Libvirt will create arbitrary files underneath this root directory. The
root directory can be kept untouched across connection open attempts if
the application needs persistence. The application is responsible for
purging everything underneath this root directory when finally no longer
required.

Even when a virt driver is used in embedded mode, it is still possible
for it to in turn use functionality that calls out to other secondary
drivers in libvirtd. For example an embedded instance of QEMU can open
the network, secret or storage drivers in the system libvirtd.

That said, the application would typically want to at least open an
embedded secret driver ("secret:///embed?root=/some/path"). Note that
multiple different embedded drivers can use the same root prefix and
co-operate just as they would inside a normal libvirtd daemon.

A key thing to note is that for this to work, the application that links
to libvirt *MUST* be built with -Wl,--export-dynamic to ensure that
symbols from libvirt.so are exported & thus available to the dynamically
loaded driver module. If libvirt.so itself was dynamically loaded then
RTLD_GLOBAL must be passed to dlopen().

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 11:03:49 +00:00