qemu: enable display/ramfb for vfio pci hostdevs

Implement display="on" and ramfb="on" for vfio PCI host devices in qemu.
This enables passthrough PCI devices for display just like we did for
mdevs.

Resolves: https://issues.redhat.com/browse/RHEL-28808

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_command.c

@@ -4735,10 +4735,16 @@ qemuBuildPCIHostdevDevProps(const virDomainDef *def,
     virDomainNetTeamingInfo *teaming;
     g_autofree char *host = virPCIDeviceAddressAsString(&pcisrc->addr);
     const char *failover_pair_id = NULL;
+    const char *driver = NULL;
 
     /* caller has to assign proper passthrough driver name */
     switch (pcisrc->driver.name) {
     case VIR_DEVICE_HOSTDEV_PCI_DRIVER_NAME_VFIO:
+        /* ramfb support requires the nohotplug variant */
+        if (pcisrc->ramfb == VIR_TRISTATE_SWITCH_ON)
+            driver = "vfio-pci-nohotplug";
+        else
+            driver = "vfio-pci";
         break;
 
     case VIR_DEVICE_HOSTDEV_PCI_DRIVER_NAME_KVM:
@@ -4762,11 +4768,13 @@ qemuBuildPCIHostdevDevProps(const virDomainDef *def,
         failover_pair_id = teaming->persistent;
 
     if (virJSONValueObjectAdd(&props,
-                              "s:driver", "vfio-pci",
+                              "s:driver", driver,
                               "s:host", host,
                               "s:id", dev->info->alias,
                               "p:bootindex", dev->info->effectiveBootIndex,
                               "S:failover_pair_id", failover_pair_id,
+                              "S:display", qemuOnOffAuto(pcisrc->display),
+                              "B:ramfb", pcisrc->ramfb,
                               NULL) < 0)
         return NULL;
 

src/qemu/qemu_validate.c

@@ -2478,6 +2478,14 @@ qemuValidateDomainDeviceDefHostdev(const virDomainHostdevDef *hostdev,
                                _("Write filtering of PCI device configuration space is not supported by qemu"));
                 return -1;
             }
+
+            if (hostdev->source.subsys.u.pci.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;
+                }
+            }
             break;
 
         case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST:

tests/qemuxmlconfdata/hostdev-pci-display-ramfb.x86_64-latest.args

@@ -0,0 +1,33 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest2 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest2/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest2/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest2/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest2,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-QEMUGuest2/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram,acpi=off \
+-accel tcg \
+-cpu qemu64 \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-vnc 127.0.0.1:0,audiodev=audio1 \
+-device '{"driver":"vfio-pci-nohotplug","host":"0000:06:12.5","id":"hostdev0","display":"on","ramfb":true,"bus":"pci.0","addr":"0x2"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on

tests/qemuxmlconfdata/hostdev-pci-display-ramfb.x86_64-latest.xml

@@ -0,0 +1,44 @@
+<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='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='custom' match='exact' check='none'>
+    <model fallback='forbid'>qemu64</model>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <controller type='usb' index='0' model='piix3-uhci'>
+      <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>
+    <audio id='1' type='none'/>
+    <video>
+      <model type='none'/>
+    </video>
+    <hostdev mode='subsystem' type='pci' managed='no' display='on' ramfb='on'>
+      <source>
+        <address domain='0x0000' bus='0x06' slot='0x12' function='0x5'/>
+      </source>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+    </hostdev>
+    <memballoon model='none'/>
+  </devices>
+</domain>

tests/qemuxmlconfdata/hostdev-pci-display-ramfb.xml

@@ -0,0 +1,33 @@
+<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='x86_64' 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-x86_64</emulator>
+    <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='pci' display='on' ramfb='on'>
+      <source>
+        <address domain='0x0000' bus='0x06' slot='0x12' function='0x5'/>
+      </source>
+    </hostdev>
+    <video>
+      <model type='none'/>
+    </video>
+    <memballoon model='none'/>
+  </devices>
+</domain>

tests/qemuxmlconftest.c

@@ -2076,6 +2076,7 @@ mymain(void)
     DO_TEST_CAPS_LATEST("hostdev-pci-address");
     DO_TEST_CAPS_LATEST("hostdev-pci-address-device");
     DO_TEST_CAPS_LATEST_PARSE_ERROR("hostdev-pci-duplicate");
+    DO_TEST_CAPS_LATEST("hostdev-pci-display-ramfb");
     DO_TEST_CAPS_LATEST("hostdev-vfio");
     DO_TEST_CAPS_LATEST("hostdev-vfio-multidomain");
     DO_TEST_CAPS_LATEST("hostdev-mdev-precreated");