Re: [libvirt] [RFC PATCH 4/7] conf: Introduce new <hostdev> attribute 'display'

QEMU introduced a new type of display for mediated devices using vfio-pci backend which controls whether a mediated device can be used as a native rendering device as an alternative to an emulated video device. This patch adds the necessary bits to domain config handling in order to expose this feature.

It's worth noting that even though QEMU supports and defaults to the value 'auto', this patch only introduces values 'on' and 'off' defaulting to 'off' (for safety), since there's no convenient way for libvirt to come up with relevant defaults based on the fact, that libvirt doesn't know whether the underlying device uses dma-buf or vfio region mapping.

Signed-off-by: Erik Skultety <eskultet(a)redhat.com&gt; --- docs/formatdomain.html.in | 16 ++++++-- docs/schemas/domaincommon.rng | 5 +++ src/conf/domain_conf.c | 18 +++++++- src/conf/domain_conf.h | 1 + src/qemu/qemu_domain.c | 43 +++++++++++++++++++ .../hostdev-mdev-display-missing-graphics.xml | 35 ++++++++++++++++ .../hostdev-mdev-display-spice-no-opengl.xml | 41 ++++++++++++++++++ .../hostdev-mdev-display-spice-opengl.xml | 41 ++++++++++++++++++ .../qemuxml2argvdata/hostdev-mdev-display-vnc.xml | 39 ++++++++++++++++++ .../hostdev-mdev-display-spice-no-opengl.xml | 47 +++++++++++++++++++++ .../hostdev-mdev-display-spice-opengl.xml | 48 ++++++++++++++++++++++ .../hostdev-mdev-display-vnc.xml | 47 +++++++++++++++++++++ tests/qemuxml2xmltest.c | 3 ++ 13 files changed, 380 insertions(+), 4 deletions(-) create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display-missing-graphics.xml create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display-spice-no-opengl.xml create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display-spice-opengl.xml create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display-vnc.xml create mode 100644 tests/qemuxml2xmloutdata/hostdev-mdev-display-spice-no-opengl.xml create mode 100644 tests/qemuxml2xmloutdata/hostdev-mdev-display-spice-opengl.xml create mode 100644 tests/qemuxml2xmloutdata/hostdev-mdev-display-vnc.xml diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index b5a6e33bfe..deecc3166a 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -4437,9 +4437,19 @@ 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 4.4.0 (QEMU 2.12)</span> libvirt added

+ a new optional <code>display</code> attribute 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 'on' or 'off' (default is 'off').

+ <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 703a1bb6f8..345bd3c757 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -4507,6 +4507,11 @@ <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 c868d8de08..7844b6d272 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -7606,6 +7606,7 @@ 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; @@ -7625,6 +7626,7 @@ 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 @@ -7712,6 +7714,15 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node, model); goto error; } + + if (display && + (mdevsrc->display = virTristateSwitchTypeFromString(display)) < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("unknown value '%s' for <hostdev> attribute " + "'display'"), + display); + goto error; + } } switch (def->source.subsys.type) { @@ -26297,9 +26308,14 @@ 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 8493dfdd76..123a676ab9 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; /* virTristateSwitchType */ 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 2c51e4c0d8..27088d4456 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -4277,10 +4277,35 @@ qemuDomainDeviceDefValidateNetwork(const virDomainNetDef *net) } +static int +qemuDomainDeviceDefValidateHostdevMdev(const virDomainHostdevSubsysMediatedDev *mdevsrc, + const virDomainDef *def) +{ + if (mdevsrc->display) {

VIR_TRISTATE_SWITCH_ABSENT

+ if (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; + } else if (def->ngraphics == 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("graphics device is needed for attribute value " + "'display=on' in <hostdev>"));

+ return -1; + } + } + + 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, @@ -4290,6 +4315,24 @@ 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 qemuDomainDeviceDefValidateHostdevMdev(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-missing-graphics.xml b/tests/qemuxml2argvdata/hostdev-mdev-display-missing-graphics.xml new file mode 100644 index 0000000000..ea559a6444 --- /dev/null +++ b/tests/qemuxml2argvdata/hostdev-mdev-display-missing-graphics.xml