Commit Graph

1149 Commits

Author SHA1 Message Date
Ján Tomko
0627150a56 qemu: build vhost-user-fs device command line
Format the 'vhost-user-fs' device on the QEMU command line.

This device provides shared file system access using the FUSE protocol
carried over virtio.
The actual file server is implemented in an external vhost-user-fs device
backend process.

https://bugzilla.redhat.com/show_bug.cgi?id=1694166

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Tested-by: Andrea Bolognani <abologna@redhat.com>
2020-03-04 12:08:50 +01:00
Ján Tomko
f0f986efa8 qemu: add code for handling virtiofsd
Start virtiofsd for each <filesystem> device using it.

Pre-create the socket for communication with QEMU and pass it
to virtiofsd.

Note that virtiofsd needs to run as root.

https://bugzilla.redhat.com/show_bug.cgi?id=1694166

Introduced by QEMU commit a43efa34c7d7b628cbf1ec0fe60043e5c91043ea

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Tested-by: Andrea Bolognani <abologna@redhat.com>
2020-03-04 12:08:50 +01:00
Peter Krempa
293e7750c9 tests: qemu: Add test data for the new <slice> element
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-14 16:32:21 +01:00
Andrea Bolognani
76121fc9c4 tests: Add test case for the armvtimer timer
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-14 12:09:17 +01:00
Jiri Denemark
8c3aed2361 qemuxml2*test: Add default CPU tests for s390-ccw-virtio-2.7 machines
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-07 09:19:02 +01:00
Stefan Berger
5e35d4a519 tests: Add test for domain XML with tpm-spapr TPM device model
This patch adds a test case for domain XML with the tpm-spapr TPM device
model.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2020-02-05 19:57:10 +01:00
Laine Stump
eb9f6cc4b3 qemu: support interface <teaming> functionality
The QEMU driver uses the <teaming type='persistent|transient'
persistent='blah'/> element to setup a "failover" pair of devices -
the persistent device must be a virtio emulated NIC, with the only
extra configuration being the addition of ",failover=on" to the device
commandline, and the transient device must be a hostdev NIC
(<interface type='hostdev'> or <interface type='network'> with a
network that is a pool of SRIOV VFs) where the extra configuration is
the addition of ",failover_pair_id=$aliasOfVirtio" to the device
commandline. These new options are supported in QEMU 4.2.0 and later.

Extra qemu-specific validation is added to ensure that the device
type/model is appropriate and that the qemu binary supports these
commandline options.

The result of this will be:

1) The virtio device presented to the guest will have an extra bit set
in its PCI capabilities indicating that it can be used as a failover
backup device. The virtio guest driver will need to be equipped to do
something with this information - this is included in the Linux
virtio-net driver in kernel 4.18 and above (and also backported to
some older distro kernels). Unfortunately there is no way for libvirt
to learn whether or not the guest driver supports failover - if it
doesn't then the extra PCI capability will be ignored and the guest OS
will just see two independent devices. (NB: the current virtio guest
driver also requires that the MAC addresses of the two NICs match in
order to pair them into a bond).

2) When a migration is requested, QEMu will automatically unplug the
transient/hostdev NIC from the guest on the source host before
starting migration, and automatically re-plug a similar device after
restarting the guest CPUs on the destination host. While the transient
NIC is unplugged, all network traffic will go through the
persistent/virtio device, but when the hostdev NIC is plugged in, it
will get all the traffic. This means that in normal circumstances the
guest gets the performance advantage of vfio-assigned "real hardware"
networking, but it can still be migrated with the only downside being
a performance penalty (due to using an emulated NIC) during the
migration.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 15:33:29 -05:00
Peter Krempa
8dc3c6ea9f tests: qemuxml: Fix and enable default-video-type* tests
The tests prefixed default-video* were enabled only for the xml2xml
testing and used impossible configurations.

Enable them for xml2argv testing fix them:
1) aarch64: remove pointless cpu mode
2) s390x: remove pointless cpu and use existing machine type
3) riscv: remove pointless cpu
4) x86: remove pointless cpu and use existing machine type
5) ppc65: use correct machine type and enable USB

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
44d32a0ac7 tests: qemuxml2argv: Modernize tpm-passthrough tests
XML->XML testing uses DO_TEST_CAPS_LATEST so use it also for the
XML->argv testing. Additionally use the same more modern machine type
in both tests.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-27 14:55:03 +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
Daniel P. Berrangé
4cf8dd0c57 qemu: add support for specifying CPU "dies" topology parameter
QEMU since 4.1.0 supports the "dies" parameter for -smp

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-16 15:11:55 +00:00
Peter Krempa
ebebf63b9c tests: qemuxml2argv: Run luks-disks-source-qcow2 case with latest caps
Try also the modern incarnation of the test.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2020-01-13 12:53:58 +01:00
Jiri Denemark
37d51dda5d qemuxml2*test: Fix hugepages-default-system-size tests
Commit v5.10.0-269-g62065a6cb5 moved NUMA validation code to domain
definition time and appropriately adjusted affected test cases except
for hugepages-default-system-size. And since we don't mock
virGetSystemPageSizeKB in our tests, hugepages-default-system-size test
would fail on architectures (ppc64le) with default page size other than
4KiB.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2020-01-13 12:52:06 +01:00
Daniel P. Berrangé
2c33532423 src: switch to use g_setenv/g_unsetenv
Eliminate direct use of normal setenv/unsetenv calls in
favour of GLib's wrapper. This eliminates two gnulib
modules

Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-03 15:42:12 +00:00
Daniel Henrique Barboza
ae2edb39b9 qemu: handle unassigned PCI hostdevs in command line
Previous patch made it possible for the QEMU driver to check if
a given PCI hostdev is unassigned, by checking if dev->info->type is
VIR_DOMAIN_DEVICE_ADDRESS_TYPE_UNASSIGNED, meaning that this device
shouldn't be part of the actual guest launch.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-18 13:08:28 -05:00
Michal Privoznik
8e2026cc18 qemu: Generate command line of NVMe disks
Now, that we have everything prepared, we can generate command
line for NVMe disks.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-12-17 10:04:44 +01:00
Daniel Henrique Barboza
83d7dadc48 qemu: command: move pcihole64 validation to qemu_domain.c
Move the pcihole64 validation being done by
qemuBuildGlobalControllerCommandLine() to the existing function
qemuDomainDeviceDefValidateControllerPCI(), which provides
domain define time validation.

The existing pcihole64 validations in qemu_domain.c were replaced
by the ones moved from qemu_command.c. The reason is that they
are more specific, allowing VIR_DOMAIN_CONTROLLER_MODEL_PCI_ROOT
and VIR_DOMAIN_CONTROLLER_MODEL_PCIE_ROOT to have distinct validation,
with exclusive QEMU caps and machine types.

Tests were adapted to consider the new caps being needed in
this earlier stage.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-16 17:51:14 -05:00
Daniel Henrique Barboza
7be4bfd25f qemu: command: move qemuBuildBootCommandLine validation to qemu_domain.c
Move the boot validation being done by qemuBuildBootCommandLine()
to to a new qemuDomainDefValidateBoot() function. This new function
is called by qemuDomainDefValidate(), allowing boot validation in
domain define time.

Tests were adapted to consider the new caps being needed in
this earlier stage.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-16 17:51:10 -05:00
Daniel Henrique Barboza
3b32de2297 qemu: command: move qemuBuildPMCommandLine validation to qemu_domain.c
Move the PM validation being done by qemuBuildPMCommandLine() to
to a new qemuDomainDefValidatePM() function. This new function
is called by qemuDomainDefValidate(), promoting PM validation in
domain define time.

Tests were adapted to consider the new caps being needed in
this earlier stage.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-16 17:51:06 -05:00
Daniel Henrique Barboza
3d21545f6d qemu: command: move qemuBuildHostdevCommandLine caps validation to qemu_domain
Move QEMU caps validation of qemuBuildHostdevCommandLine() to
qemuDomainDeviceDefValidateHostdev() and qemuDomainMdevDefValidate(),
allowing them to be validated at domain define time.

Tests were adapted to consider the new caps being needed in
this earlier stage.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-16 17:50:50 -05:00
Daniel Henrique Barboza
62065a6cb5 qemu: command: move NUMA validation to qemu_domain.c
A new qemuDomainDefValidateNuma() function was created to host
all the QEMU caps validation being done inside qemuBuildNumaArgStr().
This new function is called by qemuDomainValidateCpuCount()
to allow NUMA validation in domain define time.

Tests were changed to account for the QEMU capabilities
that need to be present at domain define time.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-16 17:50:33 -05:00
Daniel Henrique Barboza
2628247f84 qemu: command: move PSeries features validation to qemu_domain.c
Introduce a new function called qemuDomainDefValidatePSeriesFeature()
that will center all the PSeries validation done in qemu_command.c.
qemuDomainDefValidatePSeriesFeature() is then called during domain
define time, in qemuDomainDefValidateFeatures().

qemuxml2argvtest.c is also changed to include all the caps that now
are being validated in define time.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-12-16 17:50:11 -05:00
Daniel P. Berrangé
87a8b81d40 qemu: check os type / virt type / arch in validate callback
Don't check os type / virt type / arch in the post-parse callback
because we can't assume qemuCaps is non-NULL at this point. It
also conceptually belongs to the validation callback.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-12 16:30:02 +00:00
Daniel P. Berrangé
adf009b48f qemu: use host CPU object directly
Avoid grabbing the whole virCapsPtr object when we only need the
host CPU information.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:17:27 +00:00
Daniel P. Berrangé
bf9d812956 conf: drop virCapsPtr param from domain parse APIs
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:17:27 +00:00
Daniel P. Berrangé
5cedfbd100 qemu: add machines & arch to fake test capabilities cache
Currently the virQEMUCapsPtr objects are just empty. Future patches are
going to expect them to contain real data. Start off by populating the
machine types and arch information.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:15:15 +00:00
Daniel P. Berrangé
bce3b0807e qemu: cache host arch separately from virCapsPtr
As part of a goal to eliminate the need to use virCapsPtr for anything
other than the virConnectGetCapabilies() API impl, cache the host arch
against the QEMU driver struct and use that field directly.

In the tests we move virArchFromHost() globally in testutils.c so that
every test runs with a fixed default architecture reported.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:15:15 +00:00
Daniel P. Berrangé
6796a3edb3 tests: improve build time for qemuxml2argvtest
On Fedora 31 with GCC 9.2.1, compiling qemuxml2argvtest takes
about 36 seconds since

  commit 30c6d99209
  Author: Jiri Denemark <jdenemar@redhat.com>
  Date:   Thu Oct 24 17:51:42 2019 +0200

    qemuxml2argvtest: Update host arch for DO_TEST*ARCH* tests

The optimizer is hitting some pathological performance behaviour due to
the high number of branches in the mymain() method.

Pushing the branch tests down into the testCompareXMLToArgv method
brings the compile time down to 3 seconds.

This likely related to this GCC bug:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58479

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-11-28 14:30:46 +00:00
Pavel Mores
d3f2a8bd47 qemu: added tests of the new default video type selection algorithm
The test case for x86_64 and neither cirrus nor vga capability is of the
xml2argv type because it actually fails to parse the XML at all [*] which
is something that xml2xml tests don't seem to handle.  xml2argv test fails
to produce a qemu argv for this case which xml2argv tests can handle.

[*] This is a consequence of the decision not to have a fallback if the
obvious choices (cirrus and vga) aren't viable due to missing QEMU caps.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Pavel Mores <pmores@redhat.com>
2019-11-25 08:47:08 -05:00
Jiri Denemark
4a79d391b5 qemuxml2*test: Add test cases for default CPU models on x86_64
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-20 17:22:07 +01:00
Jiri Denemark
f5466786ec qemuxml2*test: Add test cases for default CPU models on s390x
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-20 17:22:07 +01:00
Jiri Denemark
9dfa2655dd qemuxml2*test: Add test cases for default CPU models on ppc64
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-20 17:22:07 +01:00
Jiri Denemark
23763b5431 qemuxml2*test: Add test cases for default CPU models on aarch64
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-20 17:22:07 +01:00
Jiri Denemark
30c6d99209 qemuxml2argvtest: Update host arch for DO_TEST*ARCH* tests
To avoid mismatch between host and QEMU capabilities.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-20 17:22:07 +01:00
Daniel Henrique Barboza
3a085d221e tests: remove unneeded cleanup labels
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-11-19 15:22:43 +01:00
Michal Privoznik
9e4445ebc3 tests: Mock access to /dev/kvm
Some of our tests try to validate domain XMLs they are working
with (not intentionally, simply because they call top level
domain XML parse function). Anyway, this implies that we build
domain capabilities also - see
virQEMUDriverGetDomainCapabilities(). And since some domain XMLs
are type of 'kvm' the control gets through
virQEMUCapsFillDomainCaps() and virHostCPUGetKVMMaxVCPUs() to
opening /dev/kvm which may be missing on the machine we're
running 'make check'.

Previously, we did not see this issue, because it was masked. If
building domain capabilities failed for whatever reason, we
ignored the failure. Only v5.9.0-207-gc69e6edea3 uncovered the
problem (it changed reval from 0 to -1 if
virQEMUDriverGetDomainCapabilities() fails). Since the referenced
commit is correct, we need to mock access to /dev/kvm in our
tests.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2019-11-15 11:56:46 +01:00
Ján Tomko
ef88698668 Use g_mkdtemp instead of mkdtemp
Prefer the GLib version to the one from gnulib.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2019-11-14 19:02:31 +01:00
Jonathon Jongsma
4b95738c8f qemu: add 'ramfb' attribute for mediated devices
The 'ramfb' attribute provides a framebuffer to the guest that can be
used as a boot display for the vgpu

For example, the following configuration can be used to provide a vgpu
with a boot display:

    <hostdev mode='subsystem' type='mdev' model='vfio-pci' display='on' ramfb='on'>
        <source>
            <address uuid='$UUID'/>
        </source>
    </hostdev>

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
2019-11-14 11:37:50 -05:00
Jonathon Jongsma
b964735609 qemu: Set capabilities properly for tests
Several tests were not specifying the necessary qemu capabilities for
what they were testing. Due to the way that the video devices are
currently validated, this is not causing any problems. But a change to
video device validation in a following patch would have exposed this
issue and resulted in multiple test failures about the domain
configuration not supporting particular video models.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
2019-11-14 11:37:50 -05:00
Jiri Denemark
ae793ecbcb qemuxml2*test: Add tests for Icelake-Server,-pconfig
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-11-12 20:14:15 +01:00
Michal Privoznik
4fa804c0c7 tests: Use g_strdup_printf() instead of virAsprintf()
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-11-12 16:15:59 +01:00
Andrea Bolognani
bd735350c5 tests: Introduce tests for ARM CPU features
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-11-07 16:09:22 +01:00
Peter Krempa
e1b5a7b383 tests: Add test case for empty 'network' cdrom
We don't allow such config in the schema but the code can handle that so
add a test case supporting it.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-21 15:59:52 +02:00
Ján Tomko
29b1e859e3 tests: use g_strdup instead of VIR_STRDUP
Replace all occurrences of
  if (VIR_STRDUP(a, b) < 0)
     /* effectively dead code */
with:
  a = g_strdup(b);

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-21 12:51:59 +02:00
Ján Tomko
64023f6d21 Use g_strdup instead of ignoring VIR_STRDUP's value
Replace all the occurrences of
  ignore_value(VIR_STRDUP(a, b));
with
  a = g_strdup(b);

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-21 12:51:55 +02:00
Julio Faracco
7286279797 conf: Add 'x' and 'y' resolution into video XML definition
This commit adds resolution element with parameters 'x' and 'y' into video
XML domain group definition. Both, properties were added into an element
called 'resolution' and it was added inside 'model' element. They are set
as optional. This element does not follow QEMU properties 'xres' and
'yres' format. Both HTML documentation and schema were changed too. This
commit includes a simple test case to cover resolution for QEMU video
models. The new XML format for resolution looks like:

    <model ...>
      <resolution x='800' y='600'/>
    </model>

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
2019-10-17 16:18:34 -04:00
Ján Tomko
67e72053c1 Use G_N_ELEMENTS instead of ARRAY_CARDINALITY
Prefer the GLib version of the macro.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-15 16:14:19 +02:00
Ján Tomko
0d94f02455 tests: use G_GNUC_UNUSED
Use G_GNUC_UNUSED from GLib instead of ATTRIBUTE_UNUSED.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-15 11:25:25 +02:00
Daniel Henrique Barboza
cab3ea2303 qemu: Implement the ccf-assist pSeries feature
This patch adds the implementation of the ccf-assist pSeries
feature, based on the QEMU_CAPS_MACHINE_PSERIES_CAP_CCF_ASSIST
capability that was added in the previous patch.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-10-09 17:51:47 -04:00
Jonathon Jongsma
fd03d0e692 qemu: add a new video device model 'ramfb'
This device is a very simple framebuffer device supported by qemu that
is mostly intended to use as a boot framebuffer in conjunction with a
vgpu. However, there is also a standalone ramfb device that can be used
as a primary display device and is useful for e.g. aarch64 guests where
different memory mappings between the host and guest can prevent use of
other devices with framebuffers such as virtio-vga.

https://bugzilla.redhat.com/show_bug.cgi?id=1679680 describes the
issues in more detail.

Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
2019-10-09 14:52:49 -04:00