From e07709c7275349eac376660c08bacc6d18f28ff8 Mon Sep 17 00:00:00 2001
From: Luo Yifan <luoyifan_yewu@cmss.chinamobile.com>
Date: Wed, 30 Nov 2022 18:13:37 +0800
Subject: [PATCH 17/24] qemu: implement vhost-user-blk support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Implements QEMU support for vhost-user-blk together with live
hotplug/unplug.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
(cherry picked from commit d763466edc6e8d4965fb42092c6e8f4296acf6c6)
Signed-off-by: Luo Yifan <luoyifan_yewu@cmss.chinamobile.com>
---
 src/qemu/qemu_block.c                         | 40 ++++++++
 src/qemu/qemu_block.h                         |  7 ++
 src/qemu/qemu_command.c                       | 93 +++++++++++++++++--
 src/qemu/qemu_command.h                       |  6 ++
 src/qemu/qemu_domain.c                        | 13 +++
 src/qemu/qemu_driver.c                        | 66 +++++++++++++
 src/qemu/qemu_hotplug.c                       | 12 ++-
 .../disk-vhostuser.x86_64-latest.args         | 40 ++++++++
 tests/qemuxml2argvtest.c                      |  1 +
 9 files changed, 268 insertions(+), 10 deletions(-)
 create mode 100644 tests/qemuxml2argvdata/disk-vhostuser.x86_64-latest.args

diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index 8bd6238238..0b7f2f6874 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -1553,6 +1553,8 @@ qemuBlockStorageSourceAttachDataFree(qemuBlockStorageSourceAttachDataPtr data)
     VIR_FREE(data->httpcookiesecretAlias);
     VIR_FREE(data->driveCmd);
     VIR_FREE(data->driveAlias);
+    VIR_FREE(data->chardevAlias);
+    VIR_FREE(data->chardevCmd);
     VIR_FREE(data);
 }
 
@@ -1719,6 +1721,13 @@ qemuBlockStorageSourceAttachApply(qemuMonitorPtr mon,
         data->driveAdded = true;
     }
 
+    if (data->chardevDef) {
+        if (qemuMonitorAttachCharDev(mon, data->chardevAlias, data->chardevDef) < 0)
+            return -1;
+
+        data->chardevAdded = true;
+    }
+
     return 0;
 }
 
@@ -1741,6 +1750,13 @@ qemuBlockStorageSourceAttachRollback(qemuMonitorPtr mon,
 
     virErrorPreserveLast(&orig_err);
 
+    if (data->chardevAdded) {
+        if (qemuMonitorDetachCharDev(mon, data->chardevAlias) < 0) {
+            VIR_WARN("Unable to remove chardev %s after failed " "qemuMonitorAddDevice",
+                     data->chardevAlias);
+        }
+    }
+
     if (data->driveAdded) {
         if (qemuMonitorDriveDel(mon, data->driveAlias) < 0)
             VIR_WARN("Unable to remove drive %s (%s) after failed "
@@ -1904,6 +1920,30 @@ qemuBlockStorageSourceChainDetachPrepareDrive(virStorageSourcePtr src,
     return g_steal_pointer(&data);
 }
 
+/**
+ * qemuBlockStorageSourceChainDetachPrepareChardev
+ * @src: storage source chain to remove
+ *
+ * Prepares qemuBlockStorageSourceChainDataPtr for detaching @src and its
+ * backingStore if -chardev was used.
+ */
+qemuBlockStorageSourceChainDataPtr
+qemuBlockStorageSourceChainDetachPrepareChardev(char *chardevAlias)
+{
+    g_autoptr(qemuBlockStorageSourceAttachData) backend = NULL;
+    g_autoptr(qemuBlockStorageSourceChainData) data = NULL;
+
+    data = g_new0(qemuBlockStorageSourceChainData, 1);
+    backend = g_new0(qemuBlockStorageSourceAttachData, 1);
+
+    backend->chardevAlias = chardevAlias;
+    backend->chardevAdded = true;
+
+    if (VIR_APPEND_ELEMENT(data->srcdata, data->nsrcdata, backend) < 0)
+        return NULL;
+
+    return g_steal_pointer(&data);
+}
 
 /**
  * qemuBlockStorageSourceChainAttach:
diff --git a/src/qemu/qemu_block.h b/src/qemu/qemu_block.h
index 2ad2ce1a1f..862572e028 100644
--- a/src/qemu/qemu_block.h
+++ b/src/qemu/qemu_block.h
@@ -94,6 +94,11 @@ struct qemuBlockStorageSourceAttachData {
     char *driveAlias;
     bool driveAdded;
 
+    virDomainChrSourceDefPtr chardevDef;
+    char *chardevAlias;
+    char *chardevCmd;
+    bool chardevAdded;
+
     virJSONValuePtr authsecretProps;
     char *authsecretAlias;
 
@@ -153,6 +158,8 @@ qemuBlockStorageSourceChainDetachPrepareBlockdev(virStorageSourcePtr src);
 qemuBlockStorageSourceChainDataPtr
 qemuBlockStorageSourceChainDetachPrepareDrive(virStorageSourcePtr src,
                                               char *driveAlias);
+qemuBlockStorageSourceChainDataPtr
+qemuBlockStorageSourceChainDetachPrepareChardev(char *chardevAlias);
 
 int
 qemuBlockStorageSourceChainAttach(qemuMonitorPtr mon,
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index bc62843783..4b12be6ede 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2152,9 +2152,16 @@ qemuBuildDiskDeviceStr(const virDomainDef *def,
         break;
 
     case VIR_DOMAIN_DISK_BUS_VIRTIO:
-        if (qemuBuildVirtioDevStr(&opt, "virtio-blk", qemuCaps,
-                                  VIR_DOMAIN_DEVICE_DISK, disk) < 0) {
-            return NULL;
+        if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+            if (qemuBuildVirtioDevStr(&opt, "vhost-user-blk", qemuCaps,
+                                      VIR_DOMAIN_DEVICE_DISK, disk) < 0) {
+                return NULL;
+            }
+        } else {
+            if (qemuBuildVirtioDevStr(&opt, "virtio-blk", qemuCaps,
+                                      VIR_DOMAIN_DEVICE_DISK, disk) < 0) {
+                return NULL;
+            }
         }
 
         if (disk->iothread)
@@ -2231,11 +2238,17 @@ qemuBuildDiskDeviceStr(const virDomainDef *def,
         virQEMUCapsGet(qemuCaps, QEMU_CAPS_DISK_SHARE_RW))
         virBufferAddLit(&opt, ",share-rw=on");
 
-    if (qemuDomainDiskGetBackendAlias(disk, qemuCaps, &backendAlias) < 0)
-        return NULL;
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        backendAlias = qemuDomainGetVhostUserChrAlias(disk->info.alias);
 
-    if (backendAlias)
-        virBufferAsprintf(&opt, ",drive=%s", backendAlias);
+        virBufferAsprintf(&opt, ",chardev=%s", backendAlias);
+    } else {
+        if (qemuDomainDiskGetBackendAlias(disk, qemuCaps, &backendAlias) < 0)
+            return NULL;
+
+        if (backendAlias)
+            virBufferAsprintf(&opt, ",drive=%s", backendAlias);
+    }
 
     virBufferAsprintf(&opt, ",id=%s", disk->info.alias);
     if (bootindex)
@@ -2453,6 +2466,9 @@ qemuBuildBlockStorageSourceAttachDataCommandline(virCommandPtr cmd,
     if (data->driveCmd)
         virCommandAddArgList(cmd, "-drive", data->driveCmd, NULL);
 
+    if (data->chardevCmd)
+        virCommandAddArgList(cmd, "-chardev", data->chardevCmd, NULL);
+
     if (data->storageProps) {
         if (!(tmp = virJSONValueToString(data->storageProps, false)))
             return -1;
@@ -2492,7 +2508,10 @@ qemuBuildDiskSourceCommandLine(virCommandPtr cmd,
     g_autofree char *copyOnReadPropsStr = NULL;
     size_t i;
 
-    if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_BLOCKDEV)) {
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        if (!(data = qemuBuildStorageSourceChainAttachPrepareChardev(disk)))
+            return -1;
+    } else if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_BLOCKDEV)) {
         if (virStorageSourceIsEmpty(disk->src))
             return 0;
 
@@ -10437,6 +10456,39 @@ qemuBuildStorageSourceAttachPrepareDrive(virDomainDiskDefPtr disk,
 }
 
 
+/**
+ * qemuBuildStorageSourceAttachPrepareChardev:
+ * @src: disk source to prepare
+ *
+ * Prepare qemuBlockStorageSourceAttachDataPtr for vhost-user disk
+ * to be used with -chardev.
+ */
+qemuBlockStorageSourceAttachDataPtr
+qemuBuildStorageSourceAttachPrepareChardev(virDomainDiskDefPtr disk)
+{
+    g_autoptr(qemuBlockStorageSourceAttachData) data = NULL;
+    g_auto(virBuffer) chardev = VIR_BUFFER_INITIALIZER;
+
+    data = g_new0(qemuBlockStorageSourceAttachData, 1);
+
+    data->chardevDef = disk->src->vhostuser;
+    data->chardevAlias = qemuDomainGetVhostUserChrAlias(disk->info.alias);
+
+    virBufferAddLit(&chardev, "socket");
+    virBufferAsprintf(&chardev, ",id=%s", data->chardevAlias);
+    virBufferAddLit(&chardev, ",path=");
+    virQEMUBuildBufferEscapeComma(&chardev, disk->src->vhostuser->data.nix.path);
+
+    qemuBuildChrChardevReconnectStr(&chardev,
+                                    &disk->src->vhostuser->data.nix.reconnect);
+
+    if (!(data->chardevCmd = virBufferContentAndReset(&chardev)))
+        return NULL;
+
+    return g_steal_pointer(&data);
+}
+
+
 /**
  * qemuBuildStorageSourceAttachPrepareCommon:
  * @src: storage source
@@ -10513,6 +10565,31 @@ qemuBuildStorageSourceChainAttachPrepareDrive(virDomainDiskDefPtr disk,
 }
 
 
+/**
+ * qemuBuildStorageSourceChainAttachPrepareChardev:
+ * @src: disk definition
+ *
+ * Prepares qemuBlockStorageSourceChainDataPtr for attaching a vhost-user
+ * disk's backend via -chardev.
+ */
+qemuBlockStorageSourceChainDataPtr
+qemuBuildStorageSourceChainAttachPrepareChardev(virDomainDiskDefPtr disk)
+{
+    g_autoptr(qemuBlockStorageSourceAttachData) elem = NULL;
+    g_autoptr(qemuBlockStorageSourceChainData) data = NULL;
+
+    data = g_new0(qemuBlockStorageSourceChainData, 1);
+
+    if (!(elem = qemuBuildStorageSourceAttachPrepareChardev(disk)))
+        return NULL;
+
+    if (VIR_APPEND_ELEMENT(data->srcdata, data->nsrcdata, elem) < 0)
+        return NULL;
+
+    return g_steal_pointer(&data);
+}
+
+
 static int
 qemuBuildStorageSourceChainAttachPrepareBlockdevOne(qemuBlockStorageSourceChainData *data,
                                                     virStorageSourcePtr src,
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index 4b1c2103c5..283aaf358c 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -115,6 +115,10 @@ qemuBlockStorageSourceAttachDataPtr
 qemuBuildStorageSourceAttachPrepareDrive(virDomainDiskDefPtr disk,
                                          const virDomainDef *def,
                                          virQEMUCapsPtr qemuCaps);
+
+qemuBlockStorageSourceAttachDataPtr
+qemuBuildStorageSourceAttachPrepareChardev(virDomainDiskDefPtr disk);
+
 int
 qemuBuildStorageSourceAttachPrepareCommon(virStorageSourcePtr src,
                                           qemuBlockStorageSourceAttachDataPtr data,
@@ -126,6 +130,8 @@ qemuBuildStorageSourceChainAttachPrepareDrive(virDomainDiskDefPtr disk,
                                               const virDomainDef *def,
                                               virQEMUCapsPtr qemuCaps);
 
+qemuBlockStorageSourceChainDataPtr
+qemuBuildStorageSourceChainAttachPrepareChardev(virDomainDiskDefPtr disk);
 
 qemuBlockStorageSourceChainDataPtr
 qemuBuildStorageSourceChainAttachPrepareBlockdev(virStorageSourcePtr top,
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index c315717c8a..b2ac1d37cc 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -7250,6 +7250,14 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk,
         return -1;
     }
 
+    if (disk->src->type == VIR_STORAGE_TYPE_VHOST_USER) {
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VHOST_USER_BLK)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("vhostuser disk is not supported with this QEMU binary"));
+            return -1;
+        }
+    }
+
     for (n = disk->src; virStorageSourceIsBacking(n); n = n->backingStore) {
         if (qemuDomainValidateStorageSource(n, qemuCaps) < 0)
             return -1;
@@ -16767,6 +16775,11 @@ qemuDomainPrepareDiskSource(virDomainDiskDefPtr disk,
                             qemuDomainObjPrivatePtr priv,
                             virQEMUDriverConfigPtr cfg)
 {
+    /* Nothing to prepare as it will use -chardev instead
+     * of -blockdev/-drive option. */
+    if (disk->src->type == VIR_STORAGE_TYPE_VHOST_USER)
+        return 0;
+
     qemuDomainPrepareDiskCachemode(disk);
 
     /* set default format for storage pool based disks */
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index b2ad021e4d..1791e3c902 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10707,6 +10707,12 @@ qemuDomainBlockResize(virDomainPtr dom,
         goto endjob;
     }
 
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("block resize is not supported for vhostuser disk"));
+        goto endjob;
+    }
+
     /* qcow2 and qed must be sized on 512 byte blocks/sectors,
      * so adjust size if necessary to round up.
      */
@@ -10798,6 +10804,12 @@ qemuDomainBlocksStatsGather(virQEMUDriverPtr driver,
             goto cleanup;
         }
 
+        if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+            virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                           _("block stats are not supported for vhostuser disk"));
+            goto cleanup;
+        }
+
         if (blockdev) {
             entryname = QEMU_DOMAIN_DISK_PRIVATE(disk)->qomName;
         } else {
@@ -10854,6 +10866,10 @@ qemuDomainBlocksStatsGather(virQEMUDriverPtr driver,
             disk = vm->def->disks[i];
             entryname = disk->info.alias;
 
+            /* No stats to report for vhost-user disk */
+            if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER)
+                continue;
+
             if (blockdev)
                 entryname = QEMU_DOMAIN_DISK_PRIVATE(disk)->qomName;
 
@@ -11483,6 +11499,12 @@ qemuDomainBlockPeek(virDomainPtr dom,
     if (!(disk = qemuDomainDiskByName(vm->def, path)))
         goto cleanup;
 
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("peeking is not supported for vhostuser disk"));
+        goto cleanup;
+    }
+
     if (disk->src->format != VIR_STORAGE_FILE_RAW) {
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
                        _("peeking is only supported for disk with 'raw' format not '%s'"),
@@ -11840,6 +11862,12 @@ qemuDomainGetBlockInfo(virDomainPtr dom,
         goto endjob;
     }
 
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("block info is not supported for vhostuser disk"));
+        goto endjob;
+    }
+
     if (virStorageSourceIsEmpty(disk->src)) {
         virReportError(VIR_ERR_INVALID_ARG,
                        _("disk '%s' does not currently have a source assigned"),
@@ -18882,6 +18910,19 @@ typedef enum {
 } qemuBlockIoTuneSetFlags;
 
 
+static bool
+qemuDomainDiskBlockIoTuneIsSupported(virStorageSourcePtr src)
+{
+    if (virStorageSourceGetActualType(src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("a block I/O throttling is not supported for vhostuser disk"));
+        return false;
+    }
+
+    return true;
+}
+
+
 /* If the user didn't specify bytes limits, inherit previous values;
  * likewise if the user didn't specify iops limits.  */
 static int
@@ -19250,6 +19291,9 @@ qemuDomainSetBlockIoTune(virDomainPtr dom,
         if (!(disk = qemuDomainDiskByName(def, path)))
             goto endjob;
 
+        if (!qemuDomainDiskBlockIoTuneIsSupported(disk->src))
+            goto endjob;
+
         if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV)) {
             qdevid = QEMU_DOMAIN_DISK_PRIVATE(disk)->qomName;
         } else {
@@ -19257,6 +19301,9 @@ qemuDomainSetBlockIoTune(virDomainPtr dom,
                 goto endjob;
         }
 
+        if (!qemuDomainDiskBlockIoTuneIsSupported(conf_disk->src))
+            goto endjob;
+
         cur_info = qemuDomainFindGroupBlockIoTune(def, disk, &info);
 
         if (qemuDomainSetBlockIoTuneDefaults(&info, cur_info,
@@ -19440,6 +19487,9 @@ qemuDomainGetBlockIoTune(virDomainPtr dom,
         if (!(disk = qemuDomainDiskByName(def, path)))
             goto endjob;
 
+        if (!qemuDomainDiskBlockIoTuneIsSupported(disk->src))
+            goto endjob;
+
         if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV)) {
             qdevid = QEMU_DOMAIN_DISK_PRIVATE(disk)->qomName;
         } else {
@@ -19461,6 +19511,10 @@ qemuDomainGetBlockIoTune(virDomainPtr dom,
                            path);
             goto endjob;
         }
+
+        if (!qemuDomainDiskBlockIoTuneIsSupported(disk->src))
+            goto endjob;
+
         reply = disk->blkdeviotune;
 
         /* Group name needs to be copied since qemuMonitorGetBlockIoThrottle
@@ -21389,6 +21443,12 @@ qemuDomainGetStatsBlockExportDisk(virDomainDiskDefPtr disk,
         VIR_INFO("optional disk '%s' source file is missing, "
                  "skip getting stats", disk->dst);
 
+        return qemuDomainGetStatsBlockExportHeader(disk, disk->src, *recordnr,
+                                                   params);
+    }
+
+    /* vhost-user disk doesn't support getting block stats */
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
         if (qemuDomainGetStatsBlockExportHeader(disk, disk->src, *recordnr,
                                                 params) < 0) {
             return -1;
@@ -22638,6 +22698,12 @@ qemuDomainSetBlockThreshold(virDomainPtr dom,
     if (!(src = qemuDomainGetStorageSourceByDevstr(dev, vm->def)))
         goto endjob;
 
+    if (virStorageSourceGetActualType(src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("setting device threshold is not supported for vhostuser disk"));
+        goto endjob;
+    }
+
     if (!src->nodestorage &&
         qemuBlockNodeNamesDetect(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)
         goto endjob;
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index c9347bac04..cb571c3161 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -702,7 +702,10 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver,
     if (qemuDomainPrepareDiskSource(disk, priv, cfg) < 0)
         goto cleanup;
 
-    if (blockdev) {
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        if (!(data = qemuBuildStorageSourceChainAttachPrepareChardev(disk)))
+            goto cleanup;
+    } else if (blockdev) {
         if (disk->copy_on_read == VIR_TRISTATE_SWITCH_ON) {
             if (!(corProps = qemuBlockStorageGetCopyOnReadProps(disk)))
                 goto cleanup;
@@ -4280,7 +4283,12 @@ qemuDomainRemoveDiskDevice(virQEMUDriverPtr driver,
               disk->info.alias, vm, vm->def->name);
 
 
-    if (blockdev) {
+    if (virStorageSourceGetActualType(disk->src) == VIR_STORAGE_TYPE_VHOST_USER) {
+        char *chardevAlias = qemuDomainGetVhostUserChrAlias(disk->info.alias);
+
+        if (!(diskBackend = qemuBlockStorageSourceChainDetachPrepareChardev(chardevAlias)))
+            goto cleanup;
+    } else if (blockdev) {
         corAlias = g_strdup(diskPriv->nodeCopyOnRead);
 
         if (diskPriv->blockjob) {
diff --git a/tests/qemuxml2argvdata/disk-vhostuser.x86_64-latest.args b/tests/qemuxml2argvdata/disk-vhostuser.x86_64-latest.args
new file mode 100644
index 0000000000..0a2b579e21
--- /dev/null
+++ b/tests/qemuxml2argvdata/disk-vhostuser.x86_64-latest.args
@@ -0,0 +1,40 @@
+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 \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object secret,id=masterKey0,format=raw,\
+file=/tmp/lib/domain--1-QEMUGuest1/master-key.aes \
+-machine pc,accel=tcg,usb=off,dump-guest-core=off \
+-cpu qemu64 \
+-m 214 \
+-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,nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-boot strict=on \
+-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 \
+-chardev socket,id=chr-vu-virtio-disk0,path=/tmp/vhost1.sock \
+-device vhost-user-blk-pci,bus=pci.0,addr=0x2,chardev=chr-vu-virtio-disk0,\
+id=virtio-disk0,bootindex=1 \
+-chardev socket,id=chr-vu-virtio-disk1,path=/tmp/vhost1.sock,reconnect=10 \
+-device vhost-user-blk-pci,bus=pci.0,addr=0x3,chardev=chr-vu-virtio-disk1,\
+id=virtio-disk1 \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
+resourcecontrol=deny \
+-msg timestamp=on
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index e07d6cf398..7b117f5984 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1209,6 +1209,7 @@ mymain(void)
     VIR_FREE(driver.config->vxhsTLSx509certdir);
     DO_TEST("disk-no-boot", NONE);
     DO_TEST_CAPS_LATEST("disk-nvme");
+    DO_TEST_CAPS_LATEST("disk-vhostuser");
     DO_TEST_PARSE_ERROR("disk-device-lun-type-invalid",
                         QEMU_CAPS_VIRTIO_SCSI);
     DO_TEST_CAPS_LATEST_PARSE_ERROR("disk-attaching-partition-nosupport");
-- 
2.27.0