Commit Graph

26606 Commits

Author SHA1 Message Date
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 Henrique Barboza
dbf1f68410 security: do not remember/recall labels for VFIO
Files inside /dev/vfio/ can't be opened more than once, meaning
that any subsequent open calls will fail. This behavior was
introduced in kernel v3.11, commit 6d6768c61b39.

When using the VFIO driver, we open a FD to /dev/vfio/N and
pass it to QEMU. If any other call attempt for the same
/dev/vfio/N happens while QEMU is still using the file, we are
unable to open it and QEMU will report -EBUSY. This can happen
if we hotplug a PCI hostdev that belongs to the same IOMMU group
of an existing domain hostdev.

The problem and solution is similar to what we already dealt
with for TPM in commit 4e95cdcbb3. This patch changes both
DAC and SELinux drivers to disable 'remember' for VFIO hostdevs
in virSecurityDACSetHostdevLabelHelper() and
virSecurityDACSetHostdevLabel(), and 'recall'
in virSecurityDACRestoreHostdevLabel() and
virSecuritySELinuxRestoreHostdevSubsysLabel().

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 13:50:51 +01:00
Daniel Henrique Barboza
09804edd0a security: Allow 'remember' to be set for HostdevLabelHelper
There is a case in which we do not want 'remember' to be
set to true in SetOwnership() calls inside the
HostdevLabelHelper() functions of both DAC and SELinux drivers.
Next patch will explain and handle that scenario.

For now, let's make virSecurityDACSetOwnership() and
virSecuritySELinuxSetHostdevLabelHelper() accept a 'remember'
flag, which will be used to set the 'remember' parameter
of their respective SetOwnership() calls. No functional
change is made.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 13:50:51 +01:00
Nikolay Shirokovskiy
93b66b3cbb qemu: when leaving iotune group update xml properly
Currently when disk is removed from iotune group (by setting
all tunables to zero) group name is leaved in config. Let's fix
it.

Given iotune defaults are taken from the destination group setting
tunables to zero may require different set of zero settings in API
call. Let's prohibit removing from group while specifying different
group name then current for the sanity sake.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:47:01 +01:00
Nikolay Shirokovskiy
57ac9f5eef qemu: get defaults from iotune group we move disk into
For example if disk is not in the group and we want to move it
there then it makes sense to specify only the group name in API call.
Currently the destination group iotune settings will be overwritten
with the disk settings which I would say is not what one would expect.
Thus let's get defaults from the group we are moving to.

And if we are moving the brand new group then is makes sense to
copy the current disk iotune settings to the group.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:46:58 +01:00
Nikolay Shirokovskiy
bb36ae81a0 qemu: fix using defaults when setting persistent iotune params
virDomainSetBlockIoTune not simply sets the iotune params given in API
but use current settings for all the omitted params. Unfortunately
it uses current settings for active config when setting inactive
params. Let's fix it.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:46:55 +01:00
Nikolay Shirokovskiy
dd94f36ffb qemu: check iotune params same for all disk in group
Currently it is possible to start a domain which have disks
in same iotune group and at the same time having different iotune
params. Both params set are passed to qemu in command line and the one
that is passed later down command line is get actually set.
Let's prohibit such configurations.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:46:51 +01:00
Nikolay Shirokovskiy
e7efffe6cb qemu: propagate iotune settings to all disks in the group
Currently upon successfull call to qemu's implementation of
virDomainSetBlockIoTune iotune settings are changed only for the
disk given in API if the disk is in iotune group while we need
to change the settings for all disks in the group.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:46:47 +01:00
Nikolay Shirokovskiy
eb4455daab conf: expand iotune params if only group name is given
Currently, if only iotune group name is given for some disk and
no any params then later start of domain will fail. I guess it
will be convenient to allow such configuration if there is
another disk in the same iotune group with iotune params set. The
meaning is that the first disk have same iotunes and the latter.
Thus one can easily add a disk to iotune group - just add group
name parameter and no need to copy all the params.

Also let's expand iotunes params in the described case so we don't
need to refer to another disk to know iotunes and this will make
logic in many places simple.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:46:42 +01:00
Nikolay Shirokovskiy
67ebd6ac26 qemu: Move qemuDiskConfigBlkdeviotuneHas* to conf
And introduce virDomainBlockIoTuneInfoHasAny.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-29 11:46:17 +01:00
Ján Tomko
374908e481 vz: fix typos of 'explicitly'
Also add a space before ending a comment.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:28 +01:00
Ján Tomko
930f6e05b9 conf: unmark xmlopt as unused in virDomainDeviceInfoParseXML
It is used by the user-alias handling code.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:28 +01:00
Ján Tomko
31375a0842 conf: remove outdated comments
Some *ParseXML functions have comments stating what kind of device
they parse with an outdated list of parameters, with the exception
of virDomainFSDefParseXML which claims to parse a disk.

Remove them, assuming the function names are descriptive enough.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:28 +01:00
Ján Tomko
d5256cbd55 qemu: eliminate ret in qemuExtDevicesStart
All the callees return either 0 or -1 so there is no need
for propagating the value. And we bail on the first error.

Remove the variable to make the function simpler.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:27 +01:00
Ján Tomko
e2ca6eb087 qemu: use def instead of vm->def in qemuExtDevicesStart
We have a helper variable to make the code more concise,
use it consistently.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:27 +01:00
Ján Tomko
f84c7c67d5 qemu: eliminate ret variable in qemuExtTPMStart
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:27 +01:00
Ján Tomko
06160f6708 qemu: eliminate ret variable in qemuExtTPMStartEmulator
Now that the cleanup section is empty, eliminate the cleanup
label as well as the 'ret' variable.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:27 +01:00
Ján Tomko
ebe9c31f41 qemu: use g_auto in qemuExtTPMStartEmulator
Use the g_auto macros wherever possible to eliminate the cleanup
section.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 13:32:27 +01:00
Ján Tomko
3efdbae5bf conf: use virXMLFormatElement in virDomainFSDefFormat
Use the virXMLFormatElement helper to format the driver element
to simplify adding further sub-elements.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2020-01-28 10:31:41 +01:00
Andrea Bolognani
c8a3a5d79b qemu_shim: Update temporary directory template
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>
2020-01-27 17:57:43 +01:00
Andrea Bolognani
7dca28e229 qemu_shim: Fix typos
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
2020-01-27 17:57:08 +01:00
Ján Tomko
c07ef7c563 qemu: snapshot: go through cleanup on error
A recent commit added an error check for too-nested backing chains
followed by a return, even though errors above jump to cleanup.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Fixes: b168fa88b8
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
2020-01-27 17:36:05 +01:00
Ján Tomko
26a42e7315 qemu_shim: cosmetic fixes
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>
2020-01-27 17:36:05 +01:00
Peter Krempa
d9dfc1f7de qemu: checkpoint: Extract calculation of bitmap merging for checkpoint deletion
This will allow some testing before refactoring.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
6796194a28 qemu: checkpoint: Introduce helper to find checkpoint disk definition in parents
The algorithm is used in two places to find the parent checkpoint object
which contains given disk and then uses data from the disk. Additionally
the code is written in a very non-obvious way. Factor out the lookup of
the disk into a function which also simplifies the callers.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
180b3422e9 qemu: domain: Remove unused qemuDomainDiskNodeFormatLookup
The function has no users now and there's no need for it as the common
pattern is to look up the whole disk object anyways.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
f19248a139 qemu: checkpoint: tolerate missing disks on checkpoint deletion
If a disk is unplugged and then the user tries to delete a checkpoint
the code would try to use NULL node name as it was not checked.

Fix this by fetching the whole disk definition object and verifying it
was found.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
7973f7d792 qemu: checkpoint: Use disk definition directly when creating checkpoint
Lookup the whole disk definition rather than just the node name.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
f3e0a45a00 qemu: checkpoint: rename disk->chkdisk in qemuCheckpointAddActions
Upcoming patches will also use the domain disk definition. Rename disk
to chkdisk for clarity.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
a303e8ea47 qemu: checkpoint: rename disk->chkdisk in qemuCheckpointDiscardBitmaps
Upcoming patches will also use the domain disk definition. Rename disk
to chkdisk for clarity.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
44e1b85717 qemu: checkpoint: split out checkpoint deletion bitmaps
qemuCheckpointDiscard is a massive function that can be separated into
smaller bits. Extract the part that actually modifies the disk from the
metadata handling.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
606dc66b09 qemu: checkpoint: Store whether deleted checkpoint is current in a variable
Avoid two computations by using a boolean.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 15:28:49 +01:00
Peter Krempa
60b580b949 qemu: capabilities: Add accessor to qemu caps machine types presence
Test code will need to know whether the virQEMUCaps object contains any
machine types already. Add a helper and expose it via 'qemu_capspriv.h'.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-27 14:55:03 +01:00
Peter Krempa
3b8feb4793 qemu: capabilities: Replace aliased machine type by copy of the canonical machine
The previous approac of just purging the alias combined with the fact
that we filled in fake machine types in the test data meant that if a
test case used an alias machine type such as 'pc' or 'q35' it would not
properly resolve to the actual data returned by qemu.

This started to be a problem since the CPU driver now looks at the
default CPU reported with the machine type.

This patch replaces the original approach of just removing the alias by
replacing it with a copy of the machine type data which the type would
alias to. This means that we are using the real data while we don't
modify the test output after every qemu upgrade.

Additionally this change will allow us to drop adding the fake machine
types later.

The test fallout is from actually excercising the CPU driver with
actual data.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-27 14:55:03 +01:00
Peter Krempa
bb61230992 qemu: capabilities: Extract code from virQEMUCapsStripMachineAliases
Separate out the internals as they will become more complex soon.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-27 14:55:03 +01:00
Peter Krempa
0b9d1a8073 qemu: domain: Validate that machine type is supported by qemu
Every supported qemu is able to return the list of machine types it
supports so we can start validating it against that list. The advantage
is a better error message, and the change will also prevent having stale
test data.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-27 14:55:03 +01:00
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
Peter Krempa
b168fa88b8 qemu: snapshot: Prevent too-nested domain XML when doing inactive snapshot
Similarly to 510d154a0b we need to prevent
doing too deeply nested backing chains and reject them with a sane error
message.

Add a loop to go through the snapshots prior to attempting actually
creating them to prevent some possible inconsistent scenarios.

We don't need to do it when reusing backing chains as we'll be
re-detecting the backing chain in that case anyways.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 14:02:01 +01:00
Peter Krempa
8e9e73a984 qemu: snapshot: Always rewrite backingStore data when reusing existing images
Don't adopt the backing store data when reusing images provided by the
user. This will force a backing chain re-probe as users might have
passed in something unexpected in the overlay where our view of the
backing chain would not correspond.

This is done only for inactive snapshots as there we have way less
verification.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2020-01-27 14:02:01 +01:00
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
Daniel P. Berrangé
207709a031 libvirt: pass a directory path into drivers for embedded usage
The intent here is to allow the virt drivers to be run directly embedded
in an arbitrary process without interfering with libvirtd. To achieve
this they need to store all their configuration & state in a separate
directory tree from the main system or session libvirtd instances.

This can be useful for doing testing of the virt drivers in "make check"
without interfering with the user's own libvirtd instances.

It can also be used for applications using KVM/QEMU as a piece of
infrastructure to build an service, rather than for general purpose
OS hosting. A long standing example is libguestfs, which would prefer
if its temporary VMs did show up in the main libvirtd VM list, because
this confuses apps such as OpenStack Nova. A more recent example would
be Kata which is using KVM as a technology to build containers.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 11:02:16 +00:00
Daniel P. Berrangé
fd2a9dda87 util: add helper API for getting URI parameters
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-27 11:02:03 +00:00
Jonathon Jongsma
dee2218bc8 qemu: explicitly disable virgl when requested
If a domain is configured to have an egl-headless display and a virtio
video device, virgl will be enabled automatically within the guest, even
if the video device is configured with accel3d='no'.

In this case we should explicitly pass 'virgl=off' to qemu.

See https://bugzilla.redhat.com/show_bug.cgi?id=1791236 for more
information.

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-25 07:51:08 +01:00
Han Han
bd51f89c30 qemu: Implement builtin rng backend
Since v4.2-rc0, QEMU introduced a builtin rng backend that uses
getrandom() syscall to generate random. Add it to libvirt with the
backend model 'builtin'.

https://bugzilla.redhat.com/show_bug.cgi?id=1785091

Signed-off-by: Han Han <hhan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-24 17:03:35 +01:00