qemu: Implement 'blob' support for virtio gpu

This can improve performance for some guests since it reduces copying of display data between host and guest. Requires udmabuf on the host. Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com> Reviewed-by: Ján Tomko <jtomko@redhat.com>
2024-09-30 11:25:47 +00:00 · 2022-02-23 15:06:55 -06:00 · 2022-02-23 15:06:55 -06:00 · 168b0ca3fc
commit 168b0ca3fc
parent 052094b5e4
13 changed files with 300 additions and 7 deletions
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@ -629,16 +629,24 @@ qemuSetupVideoCgroup(virDomainObj *vm,
 {
    qemuDomainObjPrivate *priv = vm->privateData;
    virDomainVideoAccelDef *accel = def->accel;
+    int ret;

-    if (!accel)
+    if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES))
        return 0;

-    if (!accel->rendernode ||
-        !virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES))
-        return 0;
-
-    return qemuCgroupAllowDevicePath(vm, accel->rendernode,
-                                     VIR_CGROUP_DEVICE_RW, false);
+    if (accel && accel->rendernode) {
+        ret = qemuCgroupAllowDevicePath(vm, accel->rendernode,
+                                        VIR_CGROUP_DEVICE_RW, false);
+        if (ret != 0)
+            return ret;
+    }
+    if (def->blob == VIR_TRISTATE_SWITCH_ON) {
+        ret = qemuCgroupAllowDevicePath(vm, QEMU_DEV_UDMABUF,
+                                        VIR_CGROUP_DEVICE_RW, false);
+        if (ret != 0)
+            return ret;
+    }
+    return 0;
 }

 static int
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@ -4558,6 +4558,9 @@ qemuBuildDeviceVideoCmd(virCommand *cmd,
                                  "p:vgamem", video->vram * 1024,
                                  NULL) < 0)
            return -1;
+    } else if (video->type == VIR_DOMAIN_VIDEO_TYPE_VIRTIO) {
+        if (virJSONValueObjectAdd(&props, "T:blob", video->blob, NULL) < 0)
+            return -1;
    }

    if (video->res) {
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@ -84,6 +84,7 @@ struct _qemuDomainUnpluggingDevice {
 #define QEMU_DEV_SGX_VEPVC "/dev/sgx_vepc"
 #define QEMU_DEV_SGX_PROVISION "/dev/sgx_provision"
 #define QEMU_DEVICE_MAPPER_CONTROL_PATH "/dev/mapper/control"
+#define QEMU_DEV_UDMABUF "/dev/udmabuf"


 #define QEMU_DOMAIN_AES_IV_LEN 16   /* 16 bytes for 128 bit random */
--- a/src/qemu/qemu_namespace.c
+++ b/src/qemu/qemu_namespace.c
@ -517,6 +517,25 @@ qemuDomainSetupAllGraphics(virDomainObj *vm,
 }


+static int
+qemuDomainSetupAllVideos(virDomainObj *vm,
+                         GSList **paths)
+{
+    size_t i;
+
+    VIR_DEBUG("Setting up video devices");
+    for (i = 0; i < vm->def->nvideos; i++) {
+        virDomainVideoDef *video = vm->def->videos[i];
+        if (video->blob == VIR_TRISTATE_SWITCH_ON) {
+            *paths = g_slist_prepend(*paths, g_strdup(QEMU_DEV_UDMABUF));
+            break;
+        }
+    }
+
+    return 0;
+}
+
+
 static int
 qemuDomainSetupInput(virDomainInputDef *input,
                     GSList **paths)
@ -688,6 +707,9 @@ qemuDomainBuildNamespace(virQEMUDriverConfig *cfg,
    if (qemuDomainSetupAllGraphics(vm, &paths) < 0)
        return -1;

+    if (qemuDomainSetupAllVideos(vm, &paths) < 0)
+        return -1;
+
    if (qemuDomainSetupAllInputs(vm, &paths) < 0)
        return -1;

--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@ -2792,6 +2792,15 @@ qemuValidateDomainDeviceDefVideo(const virDomainVideoDef *video,
        }
    }

+    if (video->type == VIR_DOMAIN_VIDEO_TYPE_VIRTIO) {
+        if (video->blob != VIR_TRISTATE_SWITCH_ABSENT &&
+            !virQEMUCapsGet(qemuCaps, QEMU_CAPS_VIRTIO_GPU_BLOB)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("this QEMU does not support 'blob' for virtio-gpu devices"));
+            return -1;
+        }
+    }
+
    if (video->type == VIR_DOMAIN_VIDEO_TYPE_RAMFB &&
        video->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) {
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
--- a/tests/qemuxml2argvdata/video-virtio-blob-off.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/video-virtio-blob-off.x86_64-latest.args
@ -0,0 +1,39 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/tmp/lib/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram \
+-accel tcg \
+-cpu qemu64 \
+-m 1024 \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":1073741824}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-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 \
+-no-acpi \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"file","filename":"/var/lib/libvirt/images/QEMUGuest1","node-name":"libvirt-1-storage","cache":{"direct":true,"no-flush":false},"auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":false,"cache":{"direct":true,"no-flush":false},"driver":"qcow2","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-hd","bus":"ide.0","unit":0,"drive":"libvirt-1-format","id":"ide0-0-0","bootindex":1,"write-cache":"on"}' \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-device '{"driver":"virtio-vga","id":"video0","max_outputs":1,"blob":false,"bus":"pci.0","addr":"0x2"}' \
+-device '{"driver":"virtio-gpu-pci","id":"video1","max_outputs":1,"blob":false,"bus":"pci.0","addr":"0x4"}' \
+-device '{"driver":"virtio-balloon-pci","id":"balloon0","bus":"pci.0","addr":"0x3"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
--- a/tests/qemuxml2argvdata/video-virtio-blob-off.xml
+++ b/tests/qemuxml2argvdata/video-virtio-blob-off.xml
@ -0,0 +1,36 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</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>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none'/>
+      <source file='/var/lib/libvirt/images/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <video>
+      <model type='virtio' heads='1' primary='yes' blob='off'/>
+    </video>
+    <video>
+      <model type='virtio' heads='1' primary='no' blob='off'/>
+    </video>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
--- a/tests/qemuxml2argvdata/video-virtio-blob-on.x86_64-latest.args
+++ b/tests/qemuxml2argvdata/video-virtio-blob-on.x86_64-latest.args
@ -0,0 +1,39 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/tmp/lib/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine pc,usb=off,dump-guest-core=off,memory-backend=pc.ram \
+-accel tcg \
+-cpu qemu64 \
+-m 1024 \
+-object '{"qom-type":"memory-backend-ram","id":"pc.ram","size":1073741824}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-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 \
+-no-acpi \
+-boot strict=on \
+-device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \
+-blockdev '{"driver":"file","filename":"/var/lib/libvirt/images/QEMUGuest1","node-name":"libvirt-1-storage","cache":{"direct":true,"no-flush":false},"auto-read-only":true,"discard":"unmap"}' \
+-blockdev '{"node-name":"libvirt-1-format","read-only":false,"cache":{"direct":true,"no-flush":false},"driver":"qcow2","file":"libvirt-1-storage"}' \
+-device '{"driver":"ide-hd","bus":"ide.0","unit":0,"drive":"libvirt-1-format","id":"ide0-0-0","bootindex":1,"write-cache":"on"}' \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-device '{"driver":"virtio-vga","id":"video0","max_outputs":1,"blob":true,"bus":"pci.0","addr":"0x2"}' \
+-device '{"driver":"virtio-gpu-pci","id":"video1","max_outputs":1,"blob":true,"bus":"pci.0","addr":"0x4"}' \
+-device '{"driver":"virtio-balloon-pci","id":"balloon0","bus":"pci.0","addr":"0x3"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
--- a/tests/qemuxml2argvdata/video-virtio-blob-on.xml
+++ b/tests/qemuxml2argvdata/video-virtio-blob-on.xml
@ -0,0 +1,36 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</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>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none'/>
+      <source file='/var/lib/libvirt/images/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <video>
+      <model type='virtio' heads='1' primary='yes' blob='on'/>
+    </video>
+    <video>
+      <model type='virtio' heads='1' primary='no' blob='on'/>
+    </video>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@ -2123,6 +2123,8 @@ mymain(void)
    DO_TEST("video-virtio-vga",
            QEMU_CAPS_DEVICE_VIRTIO_GPU,
            QEMU_CAPS_DEVICE_VIRTIO_VGA);
+    DO_TEST_CAPS_LATEST("video-virtio-blob-on");
+    DO_TEST_CAPS_LATEST("video-virtio-blob-off");
    DO_TEST_CAPS_LATEST("video-virtio-vga-gpu-gl");
    DO_TEST_CAPS_LATEST("video-bochs-display-device");
    DO_TEST_CAPS_LATEST("video-ramfb-display-device");
--- a/tests/qemuxml2xmloutdata/video-virtio-blob-off.x86_64-latest.xml
+++ b/tests/qemuxml2xmloutdata/video-virtio-blob-off.x86_64-latest.xml
@ -0,0 +1,48 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</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>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none'/>
+      <source file='/var/lib/libvirt/images/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <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'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <audio id='1' type='none'/>
+    <video>
+      <model type='virtio' heads='1' primary='yes' blob='off'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+    </video>
+    <video>
+      <model type='virtio' heads='1' blob='off'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+    </video>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>
--- a/tests/qemuxml2xmloutdata/video-virtio-blob-on.x86_64-latest.xml
+++ b/tests/qemuxml2xmloutdata/video-virtio-blob-on.x86_64-latest.xml
@ -0,0 +1,48 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>1048576</memory>
+  <currentMemory unit='KiB'>1048576</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>
+    <disk type='file' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none'/>
+      <source file='/var/lib/libvirt/images/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <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'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <audio id='1' type='none'/>
+    <video>
+      <model type='virtio' heads='1' primary='yes' blob='on'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
+    </video>
+    <video>
+      <model type='virtio' heads='1' blob='on'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+    </video>
+    <memballoon model='virtio'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+    </memballoon>
+  </devices>
+</domain>
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@ -1117,6 +1117,8 @@ mymain(void)
            QEMU_CAPS_DEVICE_VIRTIO_GPU_CCW);
    DO_TEST("video-none-device", QEMU_CAPS_VNC);
    DO_TEST_CAPS_LATEST("video-virtio-vga-gpu-gl");
+    DO_TEST_CAPS_LATEST("video-virtio-blob-on");
+    DO_TEST_CAPS_LATEST("video-virtio-blob-off");

    DO_TEST_CAPS_LATEST("intel-iommu");
    DO_TEST_CAPS_LATEST("intel-iommu-caching-mode");