QEMU 2.12 introduced a new type of display for mediated devices using
vfio-pci backend which allows a mediated device to be used as a VGA
compatible device as an alternative to an emulated video device. QEMU
exposes this feature via a vfio device property 'display' with supported
values 'on/off/auto' (default is 'off').
This patch adds the necessary bits to domain config handling in order to
expose this feature. Since there's no convenient way for libvirt to come
up with usable defaults for the display setting, simply because libvirt
is not able to figure out which of the display implementations - dma-buf
which requires OpenGL support vs vfio regions which doesn't need OpenGL
(works with OpenGL enabled too) - the underlying mdev uses.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
---
docs/formatdomain.html.in | 20 ++++++--
docs/schemas/domaincommon.rng | 5 ++
src/conf/domain_conf.c | 19 +++++++-
src/conf/domain_conf.h | 1 +
src/qemu/qemu_domain.c | 55 ++++++++++++++++++++++
tests/qemuxml2argvdata/hostdev-mdev-display.xml | 39 +++++++++++++++
.../hostdev-mdev-display-active.xml | 47 ++++++++++++++++++
tests/qemuxml2xmltest.c | 2 +
8 files changed, 184 insertions(+), 4 deletions(-)
create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display.xml
create mode 100644 tests/qemuxml2xmloutdata/hostdev-mdev-display-active.xml
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 9dd22554ad..3554c3dc30 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -4510,9 +4510,23 @@
guest. Currently, <code>model='vfio-pci'</code> and
<code>model='vfio-ccw'</code> (<span class="since">Since 4.4.0</span>)
is supported. Refer <a href="drvnodedev.html#MDEV">MDEV</a> to create
- a mediated device on the host. There are also some implications on the
- usage of guest's address type depending on the <code>model</code>
- attribute, see the <code>address</code> element below.
+ a mediated device on the host.
+ <span class="since">Since 4.6.0 (QEMU 2.12)</span> an optional
+ <code>display</code> attribute may be used to enable or disable
+ support for an accelerated remote desktop backed by a mediated
+ device (such as NVIDIA vGPU or Intel GVT-g) as an alternative to
+ emulated <a href="#elementsVideo">video devices</a>. This attribute
+ is limited to <code>model='vfio-pci'</code> only. Supported values
+ are either <code>on</code> or <code>off</code> (default is 'off').
+ It is required to use a
+ <a href="#elementsGraphics">graphical framebuffer</a> in order to
+ use this attribute, currently only supported with VNC, Spice and
+ egl-headless graphics devices.
+ <p>
+ Note: There are also some implications on the usage of guest's
+ address type depending on the <code>model</code> attribute,
+ see the <code>address</code> element below.
+ </p>
</dd>
</dl>
<p>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 8f7d273d9f..b8ec9c758a 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -4576,6 +4576,11 @@
<value>vfio-ccw</value>
</choice>
</attribute>
+ <optional>
+ <attribute name="display">
+ <ref name="virOnOff"/>
+ </attribute>
+ </optional>
<element name="source">
<ref name="mdevaddress"/>
</element>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 8deff5442f..bd1dc0780d 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -7646,6 +7646,7 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node,
char *rawio = NULL;
char *backendStr = NULL;
char *model = NULL;
+ char *display = NULL;
int backend;
int ret = -1;
virDomainHostdevSubsysPCIPtr pcisrc = &def->source.subsys.u.pci;
@@ -7665,6 +7666,7 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node,
sgio = virXMLPropString(node, "sgio");
rawio = virXMLPropString(node, "rawio");
model = virXMLPropString(node, "model");
+ display = virXMLPropString(node, "display");
/* @type is passed in from the caller rather than read from the
* xml document, because it is specified in different places for
@@ -7752,6 +7754,15 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node,
model);
goto cleanup;
}
+
+ if (display &&
+ (mdevsrc->display = virTristateSwitchTypeFromString(display)) <= 0) {
+ virReportError(VIR_ERR_XML_ERROR,
+ _("unknown value '%s' for <hostdev> attribute "
+ "'display'"),
+ display);
+ goto cleanup;
+ }
}
switch (def->source.subsys.type) {
@@ -7805,6 +7816,7 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node,
VIR_FREE(rawio);
VIR_FREE(backendStr);
VIR_FREE(model);
+ VIR_FREE(display);
return ret;
}
@@ -26558,9 +26570,14 @@ virDomainHostdevDefFormat(virBufferPtr buf,
virTristateBoolTypeToString(scsisrc->rawio));
}
- if (def->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV)
+ if (def->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV) {
virBufferAsprintf(buf, " model='%s'",
virMediatedDeviceModelTypeToString(mdevsrc->model));
+ if (mdevsrc->display != VIR_TRISTATE_SWITCH_ABSENT)
+ virBufferAsprintf(buf, " display='%s'",
+ virTristateSwitchTypeToString(mdevsrc->display));
+ }
+
}
virBufferAddLit(buf, ">\n");
virBufferAdjustIndent(buf, 2);
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 3deda1d978..8ca9558ceb 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -382,6 +382,7 @@ typedef struct _virDomainHostdevSubsysMediatedDev virDomainHostdevSubsysMediated
typedef virDomainHostdevSubsysMediatedDev *virDomainHostdevSubsysMediatedDevPtr;
struct _virDomainHostdevSubsysMediatedDev {
int model; /* enum virMediatedDeviceModelType */
+ int display; /* virTristateSwitch */
char uuidstr[VIR_UUID_STRING_BUFLEN]; /* mediated device's uuid string */
};
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 5da8c8bfcc..a03b1fb029 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -4450,10 +4450,47 @@ qemuDomainDeviceDefValidateNetwork(const virDomainNetDef *net)
}
+static int
+qemuDomainMdevDefValidate(const virDomainHostdevSubsysMediatedDev *mdevsrc,
+ const virDomainDef *def)
+{
+ if (mdevsrc->display != VIR_TRISTATE_SWITCH_ABSENT &&
+ mdevsrc->model != VIR_MDEV_MODEL_TYPE_VFIO_PCI) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("<hostdev> attribute 'display' is only supported"
+ " with model='vfio-pci'"));
+
+ return -1;
+ }
+
+ if (mdevsrc->display == VIR_TRISTATE_SWITCH_ON) {
+ if (def->ngraphics == 0) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+ _("graphics device is needed for attribute value "
+ "'display=on' in <hostdev>"));
+ return -1;
+ }
+
+ /* We're not able to tell whether an mdev needs OpenGL or not at the
+ * moment, so print a warning that an extra <gl> element or
+ * <graphics type='egl-headless/>' might be necessary to be added,
+ * depending on whether we're running with SPICE or VNC respectively.
+ */
+ if (!virDomainGraphicsDefHasOpenGL(def))
+ VIR_WARN("<hostdev> attribute 'display' may need the OpenGL to "
+ "be enabled");
+ }
+
+ return 0;
+}
+
+
static int
qemuDomainDeviceDefValidateHostdev(const virDomainHostdevDef *hostdev,
const virDomainDef *def)
{
+ const virDomainHostdevSubsysMediatedDev *mdevsrc;
+
/* forbid capabilities mode hostdev in this kind of hypervisor */
if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_CAPABILITIES) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -4463,6 +4500,24 @@ qemuDomainDeviceDefValidateHostdev(const virDomainHostdevDef *hostdev,
return -1;
}
+ if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS) {
+ switch ((virDomainHostdevSubsysType) hostdev->source.subsys.type) {
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB:
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI:
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI:
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST:
+ break;
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV:
+ mdevsrc = &hostdev->source.subsys.u.mdev;
+ return qemuDomainMdevDefValidate(mdevsrc, def);
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_LAST:
+ default:
+ virReportEnumRangeError(virDomainHostdevSubsysType,
+ hostdev->source.subsys.type);
+ return -1;
+ }
+ }
+
return 0;
}
diff --git a/tests/qemuxml2argvdata/hostdev-mdev-display.xml b/tests/qemuxml2argvdata/hostdev-mdev-display.xml
new file mode 100644
index 0000000000..f5b3575c04
--- /dev/null
+++ b/tests/qemuxml2argvdata/hostdev-mdev-display.xml
@@ -0,0 +1,39 @@
+<domain type='qemu' id='1'>
+ <name>QEMUGuest2</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219136</memory>
+ <currentMemory unit='KiB'>219136</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-i686</emulator>
+ <disk type='block' device='disk'>
+ <driver name='qemu' type='raw'/>
+ <source dev='/dev/HostVG/QEMUGuest2'/>
+ <target dev='hda' bus='ide'/>
+ <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+ </disk>
+ <controller type='usb' index='0'>
+ </controller>
+ <controller type='pci' index='0' model='pci-root'/>
+ <controller type='ide' index='0'>
+ </controller>
+ <graphics type='vnc'/>
+ <hostdev mode='subsystem' type='mdev' model='vfio-pci' display='on'>
+ <source>
+ <address uuid='53764d0e-85a0-42b4-af5c-2046b460b1dc'/>
+ </source>
+ </hostdev>
+ <video>
+ <model type='qxl' heads='1'/>
+ </video>
+ <memballoon model='none'/>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmloutdata/hostdev-mdev-display-active.xml b/tests/qemuxml2xmloutdata/hostdev-mdev-display-active.xml
new file mode 100644
index 0000000000..63a1a00278
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/hostdev-mdev-display-active.xml
@@ -0,0 +1,47 @@
+<domain type='qemu' id='1'>
+ <name>QEMUGuest2</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219136</memory>
+ <currentMemory unit='KiB'>219136</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-i686</emulator>
+ <disk type='block' device='disk'>
+ <driver name='qemu' type='raw'/>
+ <source dev='/dev/HostVG/QEMUGuest2'/>
+ <target dev='hda' bus='ide'/>
+ <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+ </disk>
+ <controller type='usb' index='0'>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+ </controller>
+ <controller type='pci' index='0' model='pci-root'/>
+ <controller type='ide' index='0'>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+ </controller>
+ <input type='mouse' bus='ps2'/>
+ <input type='keyboard' bus='ps2'/>
+ <graphics type='vnc' port='-1' autoport='yes'>
+ <listen type='address'/>
+ </graphics>
+ <video>
+ <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1' primary='yes'/>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+ </video>
+ <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on'>
+ <source>
+ <address uuid='53764d0e-85a0-42b4-af5c-2046b460b1dc'/>
+ </source>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+ </hostdev>
+ <memballoon model='none'/>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 3527ccdec3..14324b9c02 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -477,6 +477,8 @@ mymain(void)
DO_TEST("hostdev-pci-address", NONE);
DO_TEST("hostdev-vfio", NONE);
DO_TEST("hostdev-mdev-precreated", NONE);
+ DO_TEST_FULL("hostdev-mdev-display", WHEN_ACTIVE, GIC_NONE,
+ QEMU_CAPS_VFIO_PCI_DISPLAY);
DO_TEST("pci-rom", NONE);
DO_TEST("pci-rom-disabled", NONE);
DO_TEST("pci-rom-disabled-invalid", NONE);
--
2.14.4
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On Wed, Jul 11, 2018 at 03:58:26PM +0200, Erik Skultety wrote:
>QEMU 2.12 introduced a new type of display for mediated devices using
>vfio-pci backend which allows a mediated device to be used as a VGA
>compatible device as an alternative to an emulated video device. QEMU
>exposes this feature via a vfio device property 'display' with supported
>values 'on/off/auto' (default is 'off').
>
>This patch adds the necessary bits to domain config handling in order to
>expose this feature. Since there's no convenient way for libvirt to come
>up with usable defaults for the display setting, simply because libvirt
>is not able to figure out which of the display implementations - dma-buf
>which requires OpenGL support vs vfio regions which doesn't need OpenGL
>(works with OpenGL enabled too) - the underlying mdev uses.
>
>Signed-off-by: Erik Skultety <eskultet@redhat.com>
>---
> docs/formatdomain.html.in | 20 ++++++--
> docs/schemas/domaincommon.rng | 5 ++
> src/conf/domain_conf.c | 19 +++++++-
> src/conf/domain_conf.h | 1 +
> src/qemu/qemu_domain.c | 55 ++++++++++++++++++++++
> tests/qemuxml2argvdata/hostdev-mdev-display.xml | 39 +++++++++++++++
> .../hostdev-mdev-display-active.xml | 47 ++++++++++++++++++
> tests/qemuxml2xmltest.c | 2 +
> 8 files changed, 184 insertions(+), 4 deletions(-)
> create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display.xml
> create mode 100644 tests/qemuxml2xmloutdata/hostdev-mdev-display-active.xml
>
>@@ -7752,6 +7754,15 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node,
> model);
> goto cleanup;
> }
>+
>+ if (display &&
>+ (mdevsrc->display = virTristateSwitchTypeFromString(display)) <= 0) {
>+ virReportError(VIR_ERR_XML_ERROR,
>+ _("unknown value '%s' for <hostdev> attribute "
>+ "'display'"),
>+ display);
>+ goto cleanup;
>+ }
> }
>
> switch (def->source.subsys.type) {
>diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
>index 3deda1d978..8ca9558ceb 100644
>--- a/src/conf/domain_conf.h
>+++ b/src/conf/domain_conf.h
>@@ -382,6 +382,7 @@ typedef struct _virDomainHostdevSubsysMediatedDev virDomainHostdevSubsysMediated
> typedef virDomainHostdevSubsysMediatedDev *virDomainHostdevSubsysMediatedDevPtr;
> struct _virDomainHostdevSubsysMediatedDev {
> int model; /* enum virMediatedDeviceModelType */
>+ int display; /* virTristateSwitch */
I was convinced that using the enum type here is the right way, but I've
had my illusions shattered.
If you decide to go that way anyway, don't forget to use a temporary int
variable in the parser, since the compiler can choose to make
virTristateSwitch unsinged and it won't be able to hold the negative
return value from virTristateSwitchTypeFromString.
> char uuidstr[VIR_UUID_STRING_BUFLEN]; /* mediated device's uuid string */
> };
>
>diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
>index 5da8c8bfcc..a03b1fb029 100644
>--- a/src/qemu/qemu_domain.c
>+++ b/src/qemu/qemu_domain.c
>@@ -4450,10 +4450,47 @@ qemuDomainDeviceDefValidateNetwork(const virDomainNetDef *net)
> }
>
>
>+static int
>+qemuDomainMdevDefValidate(const virDomainHostdevSubsysMediatedDev *mdevsrc,
>+ const virDomainDef *def)
>+{
>+ if (mdevsrc->display != VIR_TRISTATE_SWITCH_ABSENT &&
>+ mdevsrc->model != VIR_MDEV_MODEL_TYPE_VFIO_PCI) {
>+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>+ _("<hostdev> attribute 'display' is only supported"
>+ " with model='vfio-pci'"));
>+
>+ return -1;
>+ }
>+
>+ if (mdevsrc->display == VIR_TRISTATE_SWITCH_ON) {
>+ if (def->ngraphics == 0) {
>+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>+ _("graphics device is needed for attribute value "
>+ "'display=on' in <hostdev>"));
>+ return -1;
>+ }
>+
>+ /* We're not able to tell whether an mdev needs OpenGL or not at the
>+ * moment, so print a warning that an extra <gl> element or
>+ * <graphics type='egl-headless/>' might be necessary to be added,
>+ * depending on whether we're running with SPICE or VNC respectively.
>+ */
>+ if (!virDomainGraphicsDefHasOpenGL(def))
>+ VIR_WARN("<hostdev> attribute 'display' may need the OpenGL to "
>+ "be enabled");
I'd suggest dropping the warning - nobody reads warnings.
>+ }
>+
>+ return 0;
>+}
>+
>+
> static int
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Jano
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