Commit Graph

841 Commits

Author SHA1 Message Date
Andrea Bolognani
2f06757048 docs: Expand documentation for the tickpolicy timer attribute
The current documentation is fairly terse and not easy to decode
for someone who's not intimately familiar with the inner workings
of timer devices. Expand on it by providing a somewhat verbose
description of what behavior each policy will result in, as seen
from both the guest OS and host point of view.

This is lifted directly from QEMU commit

  commit 2a7d957596786404c4ed16b089273de95a9580ad
  Author: Andrea Bolognani <abologna@redhat.com>
  Date:   Tue Feb 11 19:37:44 2020 +0100

    qapi: Expand documentation for LostTickPolicy

  v4.2.0-1442-g2a7d957596

The original text also matched word for word the documentation
found in QEMU.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-02-21 11:42:47 +01:00
Peter Krempa
44f0f76890 docs: Document the new <slices> sub-element of disk's <source>
We are going to add support for specifying offset and size attributes
which will allow controling where the image and where the guest data
itself starts in the source of the disk. This will be represented by
a <slices> element filled with either a <slice type='storage'> for the
offset of the image format data.

Add the XML documentation and RNG schema.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-14 16:32:21 +01:00
Peter Krempa
4e93c47576 docs: formatdomain: Close <source> on one of disk examples
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
1d742a8772 docs: List the armvtimer timer among all others
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-14 12:09:19 +01:00
Andrea Bolognani
c4a78d00f8 docs: Improve documentation for <serial> and <console>
Users expect to be able to configure the <console> element and see
that configuration reflected into the <serial> element or at least
sticking, however due to our crazy back-compat code that doesn't
always happen.

There's really not much we can do to make this kind of corner cases
work as the user would expect, especially not without introducing
additional complexity in a part of libvirt that already has more
than a fair share of it; we can, however, improve the documentation
so that it will nudge said users in the right direction.

https://bugzilla.redhat.com/show_bug.cgi?id=1770725

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2020-02-11 17:21:14 +01:00
Stefan Berger
914cb83218 conf: Add support for tpm-spapr to domain XML
This patch adds support for the tpm-spapr device model for ppc64. The XML for
this type of TPM looks as follows:

 <tpm model='tpm-spapr'>
   <backend type='emulator'/>
 </tpm>

Extend the documentation.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2020-02-05 19:57:10 +01:00
Ján Tomko
5b63cb5abf docs: fix a typo
s/axnd/and/

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Fixes: f0f34056ab
2020-01-31 15:57:00 +01:00
Laine Stump
f0f34056ab docs: document <interface> subelement <teaming>
Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-29 15:33:29 -05:00
Han Han
6a6d00e168 conf: Add rng backend model builtin
The 'builtin' rng backend model can be used as following:
  <rng model='virtio'>
    <backend model='builtin'/>
  </rng>

Signed-off-by: Han Han <hhan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2020-01-24 17:03:32 +01:00
Daniel P. Berrangé
fbf27730a3 conf: add support for specifying CPU "dies" parameter
Recently CPU hardware vendors have started to support a new structure
inside the CPU package topology known as a "die". Thus the hierarchy
is now:

  sockets > dies > cores > threads

This adds support for "dies" in the XML parser, with the value
defaulting to 1 if not specified for backwards compatibility.

For example a system with 64 logical CPUs might report

   <topology sockets="4" dies="2" cores="4" threads="2"/>

Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-16 15:11:42 +00:00
Ján Tomko
54ba7da585 docs: formatdomain: use 'element' instead of 'block'
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-08 09:51:01 +01:00
Sebastian Mitterle
97c7f3ead4 security: improve security driver error message
Currently, when security driver is not available users are informed that
it wasn't found which can be confusing.
1. Update error message
2. Add comment to domain doc

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by Sebastian Mitterle <smitterl@redhat.com>
2020-01-07 14:44:32 +00:00
Daniel Henrique Barboza
bc076ae995 formatdomain.html.in: document <address type='unassigned'/>
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
e1b022890e schemas: Introduce disk type NVMe
There is this class of PCI devices that act like disks: NVMe.
Therefore, they are both PCI devices and disks. While we already
have <hostdev/> (and can assign a NVMe device to a domain
successfully) we don't have disk representation. There are three
problems with PCI assignment in case of a NVMe device:

1) domains with <hostdev/> can't be migrated

2) NVMe device is assigned whole, there's no way to assign only a
   namespace

3) Because hypervisors see <hostdev/> they don't put block layer
   on top of it - users don't get all the fancy features like
   snapshots

NVMe namespaces are way of splitting one continuous NVDIMM memory
into smaller ones, effectively creating smaller NVMe-s (which can
then be partitioned, LVMed, etc.)

Because of all of this the following XML was chosen to model a
NVMe device:

  <disk type='nvme' device='disk'>
    <driver name='qemu' type='raw'/>
    <source type='pci' managed='yes' namespace='1'>
      <address domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    </source>
    <target dev='vda' bus='virtio'/>
  </disk>

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
2019-12-17 10:04:43 +01:00
Daniel P. Berrangé
6430c00552 conf: pass in default architecture via domain XML options
When parsing the guest XML we must fill in the default guest arch if it
is not already present because later parts of the parsing process need
this information.

If no arch is specified we lookup the first guest in the capabilities
data matching the os type and virt type. In most cases this will result
in picking the host architecture but there are some exceptions...

 - The test driver is hardcoded to always use i686 arch
 - The VMWare/ESX drivers will always place i686 guests ahead
   of x86_64 guests in capabilities, so effectively they always
   use i686
 - The QEMU driver can potentially return any arch at all
   depending on what combination of QEMU binaries are installed.

The domain XML hardware configurations are inherently architecture
specific in many places. As a result whomever/whatever created the
domain XML will have had a particular architecture in mind when
specifying the config. In pretty much any sensible case this arch
will have been the native host architecture. i686 on x86_64 is
the only sensible divergance because both these archs are
compatible from a domaain XML config POV.

IOW, although the QEMU driver can pick an almost arbitrary arch as its
default, in the real world no application or user is likely to be
relying on this default arch being anything other than native.

With all this in mind, it is reasonable to change the XML parser to
allow the default architecture to be passed via the domain XML options
struct. If no info is explicitly given then it is safe & sane to pick
the host native architecture as the default for the guest.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:15:16 +00:00
Andrea Bolognani
4d0a4b39f8 docs: Update minimum QEMU version for kvm-hint-dedicated
Same fix that was applied to release notes in a595c66a13.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
2019-12-06 09:29:05 +01:00
Peter Krempa
4321bd0dd2 docs: Document support for obeying <backingStore> of <disk> on input
Until now we've only supported <backingStore> in an output mode. The
documentation for the element states that hypervisor drivers may start
to obey it in the future.

Update the documentation so that it mentions the recently added
'backingStoreInput' domain capability and explain what happens if it is
supported and <backingStore> is present on input.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-11-22 12:51:27 +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
cda4d4d212 qemu: fix documentation for video resolution
The video resolution support that was introduced in
7286279797 is specified as a <resolution>
sub-element of <model>, not optional attributes of model.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
2019-11-13 13:08:33 -05:00
Jim Fehlig
962647cac6 docs: Fix attribute names in filesystem/driver example
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
2019-11-01 11:46:55 -06:00
Jim Fehlig
cbff7c37f2 docs: Fix version that introduced Xen support for ACPI firmware
Xen support for specifying ACPI firmware path was introduced in the
5.9.0 dev cycle, not 5.8.0 as currently indicated by the docs.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-11-01 08:23:08 -06:00
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
Ivan Kardykov
03e98a52d2 libxl: add acpi slic table support
Libxl driver did not support setup additional acpi firmware to xen
guest. It is necessary to activate OEM Windows installs. This patch
allow to define in OS section acpi table param (which supported domain
common schema).

Signed-off-by: Ivan Kardykov <kardykov@tabit.pro>
[added info to docs/formatdomain.html.in]
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
2019-10-10 21:01:54 -06:00
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
Luyao Zhong
cd62dbc03b clarify the xml example for NVDIMM more clealy
The NVDIMM backend file can be a normal file or a real device file,
Current xml example and explainations may mislead users. So add more
info about the NVDIMM related elements and update the xml examples.

Signed-off-by: Luyao Zhong <luyao.zhong@intel.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-09-30 16:28:18 +02:00
Marc-André Lureau
1394bf1091 domain: add rendernode attribute on <accel>
vhost-user-gpu helper takes --render-node option to specify on which
GPU should the renderning be done.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-09-24 12:17:39 -04:00
Marc-André Lureau
bc1e924cf0 conf: format/parse/rng/docs for video <driver name='qemu|vhostuser'/>
Accept a new driver name attribute to specify usage of helper process, ex:

  <video>
    <driver name='vhostuser'/>
    <model type='virtio'/>
  </video>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-09-24 12:17:39 -04:00
Laine Stump
77f72a8615 conf: new "managed" attribute for target dev of <interface type='ethernet'>
Although <interface type='ethernet'> has always been able to use an
existing tap device, this is just a coincidence due to the fact that
the same ioctl is used to create a new tap device or get a handle to
an existing device.

Even then, once we have the handle to the device, we still insist on
doing extra setup to it (setting the MAC address and IFF_UP).  That
*might* be okay if libvirtd is running as a privileged process, but if
libvirtd is running as an unprivileged user, those attempted
modifications to the tap device will fail (yes, even if the tap is set
to be owned by the user running libvirtd). We could avoid this if we
knew that the device already existed, but as stated above, an existing
device and new device are both accessed in the same manner, and
anyway, we need to preserve existing behavior for those who are
already using pre-existing devices with privileged libvirtd (and
allowing/expecting libvirt to configure the pre-existing device).

In order to cleanly support the idea of using a pre-existing and
pre-configured tap device, this patch introduces a new optional
attribute "managed" for the interface <target> element. This
attribute is only valid for <interface type='ethernet'> (since all
other interface types have mandatory config that doesn't apply in the
case where we expect the tap device to be setup before we
get it). The syntax would look something like this:

   <interface type='ethernet'>
      <target dev='mytap0' managed='no'/>
      ...
   </interface>

This patch just adds managed to the grammar and parser for <target>,
but has no functionality behind it.

(NB: when managed='no' (the default when not specified is 'yes'), the
target dev is always a name explicitly provided, so we don't
auto-remove it from the config just because it starts with "vnet"
(VIR_NET_GENERATED_TAP_PREFIX); this makes it possible to use the
same pattern of names that libvirt itself uses when it automatically
creates the tap devices.)

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-09-09 14:35:54 -04:00
Vitaly Kuznetsov
65c02db98d conf: add support for Direct Mode for Hyper-V Synthetic timers
Support 'Direct Mode' for Hyper-V Synthetic Timers in domain config.
Make it 'stimer' enlightenment option as it is not a separate thing.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2019-08-19 11:38:28 +02:00
Wim ten Have
cb12c59dac qemu: support for kvm-hint-dedicated performance hint
QEMU version 2.12.1 introduced a performance feature under commit
be7773268d98 ("target-i386: add KVM_HINTS_DEDICATED performance hint")

This patch adds a new KVM feature 'hint-dedicated' to set this performance
hint for KVM guests. The feature is off by default.

To enable this hint and have libvirt add "-cpu host,kvm-hint-dedicated=on"
to the QEMU command line, the following XML code needs to be added to the
guest's domain description in conjunction with CPU mode='host-passthrough'.

  <features>
    <kvm>
      <hint-dedicated state='on'/>
    </kvm>
  </features>
  ...
  <cpu mode='host-passthrough ... />

Signed-off-by: Wim ten Have <wim.ten.have@oracle.com>
Signed-off-by: Menno Lageman <menno.lageman@oracle.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-08-12 15:13:04 +02:00
Paolo Bonzini
0848af78ae docs: formatdomain: explain host-model/host-passthrough requirements
host-passthrough documentation menions that the source and destination
hosts are not identical in both hardware and configuration.  Configuration
actually includes microcode version and QEMU version, but this is not
clear so make it explicit

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20190802125415.15227-1-pbonzini@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2019-08-09 10:55:59 +02:00
Vitaly Kuznetsov
37ce8cfaa3 docs: formatdomain: move 'msrs' out of Hyper-V Enlightenments
Introduced by: commit e9528f41c6

'msrs' is a feature unrelated to Hyper-V Enlightenments, the commit message
which added it and the test have it right:

    <features>
      ...
      <msrs unknown='ignore'>
      ...
    </features>

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2019-07-30 12:44:58 +02:00
Vitaly Kuznetsov
08dec3b086 docs: formatdomain: fix 'SynIC' spelling
SynIC stands for 'Synthetic Interrupt Controller', it is not a NIC. Fix the
spelling in accordance with Hypervisor Top Level Functional Specification.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2019-07-30 12:44:58 +02:00
Vitaly Kuznetsov
db9829d795 docs: formatdomain: add stimer flag to the example xml
The example XML we have contains all other Hyper-V Enlightenments but
'stimer' is missing.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2019-07-30 12:44:58 +02:00
Stefan Berger
b2f6a5c688 docs: Extend TPM docs with new encryption element
Describe the encryption element in the TPM's domain XML.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-07-26 10:31:02 +01:00
Ján Tomko
ca12af4915 docs: formatdomain: tsc is supported by QEMU
As of commit 7373c4e48 the QEMU driver also supports TSC.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
2019-07-17 17:33:56 +02:00
Ján Tomko
5c5831c454 docs: formatdomain: remove stray nbsp
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
2019-07-17 17:33:56 +02:00
Jonathon Jongsma
e579f5300b qemu: add 'bochs' video display type
Update schema and configuration to allow specifying new video type of
'bochs'. Add implementation and tests for qemu.

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
2019-07-15 10:21:21 +02:00
Andrea Bolognani
913500936b docs: Update documentation for spapr-vio addresses
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-06-20 12:50:07 +02:00
Andrea Bolognani
73713a54a8 docs: Advertise pcie-to-pci-bridge for use on q35
We support pcie-to-pci-bridge, and prefer it to
dmi-to-pci-bridge, since libvirt 4.3.0, but we didn't
update all the documentation accordingly at the time.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-06-20 10:03:22 +02:00
Ján Tomko
53f3c43ac7 docs: fix some typos in networkport documentation
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
2019-06-18 14:35:43 +02:00
Daniel P. Berrangé
90064d76bc conf: record a portid against the domain conf
The portid will be the UUID of the virNetworkPort object associated
with the network interface when a guest is running.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-06-17 15:45:09 +01:00
Andrea Bolognani
60f4c41377 conf: Parse and format SMMUv3 IOMMU
SMMUv3 is an IOMMU implementation for ARM virt guests.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-06-03 17:40:48 +02:00
Erik Skultety
f3e777a3c4 docs: Change the 'Launch Security' section id to "launchSecurity"
Although there's currently only support for SEV, it's likely other
solutions will appear, so we should not refer to the documentation
section simply with 'sev'.

Signed-off-by: Erik Skultety <eskultet@redhat.com>
2019-05-23 14:29:00 +02:00
Fabiano Fidêncio
e34b5938a9 docs: Fix typo in the firmware value
firmware attribute from <os/> takes either 'efi' or 'bios' as its
allowed values. However, the current documentation mistakenly mentions
'uefi' instead of 'efi'.

Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>
2019-04-29 16:53:26 +02:00
Martin Kletzander
842bc56ad2 conf: Add support for emulatorsched
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-04-16 13:46:17 +02:00
Martin Kletzander
c79a39e60c docs: Mention iothreadsched element in the docs and reword
Just one missing occurrence of iothreadsched fixed plus some rewording for this
to make more sense for the readers.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-04-16 13:46:17 +02:00
Pino Toscano
3958e3d6a5 docs: document firmware attribute for VMware guests
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Pino Toscano <ptoscano@redhat.com>
2019-04-15 20:03:55 -04:00
Jim Fehlig
09eb1ae0ec conf: Add a new 'xenbus' controller type
xenbus is virtual controller (akin to virtio controllers) for Xen
paravirtual devices. Although all Xen VMs have a xenbus, it has
never been modeled in libvirt, or in Xen native VM config format
for that matter.

Recently there have been requests to support Xen's max_grant_frames
setting in libvirt. max_grant_frames is best modeled as an attribute
of xenbus. It describes the maximum IO buffer space (or DMA space)
available in xenbus for use by connected paravirtual devices. This
patch introduces a new xenbus controller type that includes a
maxGrantFrames attribute.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-03-13 12:06:52 -06:00