Re: [libvirt] [PATCH v3 6/8] conf: Introduce new <hostdev> attribute 'display'

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(a)redhat.com&gt; --- 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 */

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