From 2d16cb96407ed22af46b892e3319f04ac61924ed Mon Sep 17 00:00:00 2001

Message-Id: <2d16cb96407ed22af46b892e3319f04ac61924ed@dist-git>

From: Erik Skultety <eskultet@redhat.com>

Date: Thu, 19 Jul 2018 15:04:02 +0200

Subject: [PATCH] conf: Introduce new <hostdev> attribute 'display'

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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' (libvirt will default to '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.

Reviewed-by: Ján Tomko <jtomko@redhat.com>

Signed-off-by: Erik Skultety <eskultet@redhat.com>

(cherry picked from commit d54e45b6edd7623e488a19e30bc4148a21fa8b03)

https://bugzilla.redhat.com/show_bug.cgi?id=1475770

Signed-off-by: Erik Skultety <eskultet@redhat.com>

Reviewed-by: Ján Tomko <jtomko@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                        | 98 ++++++++++++++++++-

 .../qemuxml2argvdata/hostdev-mdev-display.xml | 39 ++++++++

 .../hostdev-mdev-display.xml                  | 47 +++++++++

 tests/qemuxml2xmltest.c                       |  1 +

 8 files changed, 222 insertions(+), 8 deletions(-)

 create mode 100644 tests/qemuxml2argvdata/hostdev-mdev-display.xml

 create mode 100644 tests/qemuxml2xmloutdata/hostdev-mdev-display.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, model='vfio-pci' and

           model='vfio-ccw' (Since 4.4.0)

           is supported. Refer MDEV to create

-          a mediated device on the host. There are also some implications on the

-          usage of guest's address type depending on the model

-          attribute, see the address element below.

+          a mediated device on the host.

+          Since 4.6.0 (QEMU 2.12) an optional

+          display 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 video devices. This attribute

+          is limited to model='vfio-pci' only. Supported values

+          are either on or off (default is 'off').

+          It is required to use a

+          graphical framebuffer in order to

+          use this attribute, currently only supported with VNC, Spice and

+          egl-headless graphics devices.

+          

+            Note: There are also some implications on the usage of guest's

+            address type depending on the model attribute,

+            see the address element below.

+          

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng

index 157726752c..be8430ab22 100644

--- a/docs/schemas/domaincommon.rng

+++ b/docs/schemas/domaincommon.rng

@@ -4579,6 +4579,11 @@

         <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 72086f9e86..830c298158 100644

--- a/src/conf/domain_conf.c

+++ b/src/conf/domain_conf.c

@@ -7656,6 +7656,7 @@ 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;

@@ -7675,6 +7676,7 @@ 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

@@ -7762,6 +7764,15 @@ 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) {

@@ -7815,6 +7826,7 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr node,

     VIR_FREE(rawio);

     VIR_FREE(backendStr);

     VIR_FREE(model);

+    VIR_FREE(display);

     return ret;

 }

@@ -26568,9 +26580,14 @@ 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 9498594857..5337f1ce55 100644

--- a/src/qemu/qemu_domain.c

+++ b/src/qemu/qemu_domain.c

@@ -4451,9 +4451,48 @@ qemuDomainDeviceDefValidateNetwork(const virDomainNetDef *net)

 static int

-qemuDomainDeviceDefValidateHostdev(const virDomainHostdevDef *hostdev,

-                                   const virDomainDef *def)

+qemuDomainMdevDefValidate(const virDomainHostdevSubsysMediatedDev *mdevsrc,

+                          const virDomainDef *def,

+                          virQEMUCapsPtr qemuCaps)

 {

+    if (mdevsrc->display == VIR_TRISTATE_SWITCH_ABSENT)

+        return 0;

+

+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_VFIO_PCI_DISPLAY)) {

+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",

+                       _("display property of device vfio-pci is "

+                         "not supported by this version of QEMU"));

+        return -1;

+    }

+

+    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;

+    }

+

+    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;

+        }

+    }

+

+    return 0;

+}

+

+

+static int

+qemuDomainDeviceDefValidateHostdev(const virDomainHostdevDef *hostdev,

+                                   const virDomainDef *def,

+                                   virQEMUCapsPtr qemuCaps)

+{

+    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 +4502,24 @@ 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, qemuCaps);

+        case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_LAST:

+        default:

+            virReportEnumRangeError(virDomainHostdevSubsysType,

+                                    hostdev->source.subsys.type);

+            return -1;

+        }

+    }

+

     return 0;

 }

@@ -5595,7 +5652,8 @@ qemuDomainDeviceDefValidate(const virDomainDeviceDef *dev,

         break;

     case VIR_DOMAIN_DEVICE_HOSTDEV:

-        ret = qemuDomainDeviceDefValidateHostdev(dev->data.hostdev, def);

+        ret = qemuDomainDeviceDefValidateHostdev(dev->data.hostdev, def,

+                                                 qemuCaps);

         break;

     case VIR_DOMAIN_DEVICE_VIDEO:

@@ -6205,6 +6263,35 @@ qemuDomainVsockDefPostParse(virDomainVsockDefPtr vsock)

 }

+static int

+qemuDomainHostdevDefMdevPostParse(virDomainHostdevSubsysMediatedDevPtr mdevsrc,

+                                  virQEMUCapsPtr qemuCaps)

+{

+    /* QEMU 2.12 added support for vfio-pci display type, we default to

+     * 'display=off' to stay safe from future changes */

+    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_VFIO_PCI_DISPLAY) &&

+        mdevsrc->display == VIR_TRISTATE_SWITCH_ABSENT)

+        mdevsrc->display = VIR_TRISTATE_SWITCH_OFF;

+

+    return 0;

+}

+

+

+static int

+qemuDomainHostdevDefPostParse(virDomainHostdevDefPtr hostdev,

+                              virQEMUCapsPtr qemuCaps)

+{

+    virDomainHostdevSubsysPtr subsys = &hostdev->source.subsys;

+

+    if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&

+        hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV &&

+        qemuDomainHostdevDefMdevPostParse(&subsys->u.mdev, qemuCaps) < 0)

+        return -1;

+

+    return 0;

+}

+

+

 static int

 qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,

                              const virDomainDef *def,

@@ -6255,11 +6342,14 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,

         ret = qemuDomainVsockDefPostParse(dev->data.vsock);

         break;

+    case VIR_DOMAIN_DEVICE_HOSTDEV:

+        ret = qemuDomainHostdevDefPostParse(dev->data.hostdev, qemuCaps);

+        break;

+

     case VIR_DOMAIN_DEVICE_LEASE:

     case VIR_DOMAIN_DEVICE_FS:

     case VIR_DOMAIN_DEVICE_INPUT:

     case VIR_DOMAIN_DEVICE_SOUND:

-    case VIR_DOMAIN_DEVICE_HOSTDEV:

     case VIR_DOMAIN_DEVICE_WATCHDOG:

     case VIR_DOMAIN_DEVICE_GRAPHICS:

     case VIR_DOMAIN_DEVICE_HUB:

diff --git a/tests/qemuxml2argvdata/hostdev-mdev-display.xml b/tests/qemuxml2argvdata/hostdev-mdev-display.xml

new file mode 100644

index 0000000000..f37e08e1b9

--- /dev/null

+++ b/tests/qemuxml2argvdata/hostdev-mdev-display.xml

@@ -0,0 +1,39 @@

+<domain type='qemu'>

+  <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.xml b/tests/qemuxml2xmloutdata/hostdev-mdev-display.xml

new file mode 100644

index 0000000000..94c11b1199

--- /dev/null

+++ b/tests/qemuxml2xmloutdata/hostdev-mdev-display.xml

@@ -0,0 +1,47 @@

+<domain type='qemu'>

+  <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 fa57221d62..e418e67f6c 100644

--- a/tests/qemuxml2xmltest.c

+++ b/tests/qemuxml2xmltest.c

@@ -479,6 +479,7 @@ mymain(void)

     DO_TEST("hostdev-pci-address", NONE);

     DO_TEST("hostdev-vfio", NONE);

     DO_TEST("hostdev-mdev-precreated", NONE);

+    DO_TEST("hostdev-mdev-display", QEMU_CAPS_VFIO_PCI_DISPLAY);

     DO_TEST("pci-rom", NONE);

     DO_TEST("pci-rom-disabled", NONE);

     DO_TEST("pci-rom-disabled-invalid", NONE);

-- 

2.18.0