[3/6] conf: Add <disk model='virtio-{non-}transitional'/>

Message ID 44a971b1e403a2480f2e0748727944b3b98dd09a.1547420060.git.crobinso@redhat.com
State New
Headers show
Series
  • RFC: qemu: virtio-{non-}transitional support
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Commit Message

Cole Robinson Jan. 13, 2019, 11:12 p.m.
<disk> devices lack the model= attribute which is used by
most other device types. bus= mostly acts as one, but it
serves other purposes too like determing what target=
prefix to use, and for matching against controller type=
values.

Extending bus= to handle additional virtio transitional
devices will complicate apps lives, and it isn't a clean
mapping anyways. So let's bite the bullet and add a new
<disk model=X/> attribute, and wire up common handling
for virtio-{non-}transitional

Signed-off-by: Cole Robinson <crobinso@redhat.com>

---
 docs/formatdomain.html.in                     |  8 ++++
 docs/schemas/domaincommon.rng                 |  8 ++++
 src/conf/domain_conf.c                        | 28 +++++++++++++
 src/conf/domain_conf.h                        | 10 +++++
 src/libvirt_private.syms                      |  2 +
 ...virtio-non-transitional.x86_64-latest.args | 34 +++++++++++++++
 .../virtio-non-transitional.xml               | 26 ++++++++++++
 .../virtio-transitional.x86_64-latest.args    | 34 +++++++++++++++
 .../qemuxml2argvdata/virtio-transitional.xml  | 26 ++++++++++++
 tests/qemuxml2argvtest.c                      |  3 ++
 .../virtio-non-transitional.xml               | 42 +++++++++++++++++++
 .../virtio-transitional.xml                   | 42 +++++++++++++++++++
 tests/qemuxml2xmltest.c                       |  3 ++
 13 files changed, 266 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/virtio-non-transitional.x86_64-latest.args
 create mode 100644 tests/qemuxml2argvdata/virtio-non-transitional.xml
 create mode 100644 tests/qemuxml2argvdata/virtio-transitional.x86_64-latest.args
 create mode 100644 tests/qemuxml2argvdata/virtio-transitional.xml
 create mode 100644 tests/qemuxml2xmloutdata/virtio-non-transitional.xml
 create mode 100644 tests/qemuxml2xmloutdata/virtio-transitional.xml

-- 
2.20.1

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Comments

Daniel P. Berrangé Jan. 15, 2019, 4:51 p.m. | #1
On Sun, Jan 13, 2019 at 06:12:05PM -0500, Cole Robinson wrote:
> <disk> devices lack the model= attribute which is used by

> most other device types. bus= mostly acts as one, but it

> serves other purposes too like determing what target=

> prefix to use, and for matching against controller type=

> values.

> 

> Extending bus= to handle additional virtio transitional

> devices will complicate apps lives, and it isn't a clean

> mapping anyways. So let's bite the bullet and add a new

> <disk model=X/> attribute, and wire up common handling

> for virtio-{non-}transitional

> 

> Signed-off-by: Cole Robinson <crobinso@redhat.com>

> ---

>  docs/formatdomain.html.in                     |  8 ++++

>  docs/schemas/domaincommon.rng                 |  8 ++++

>  src/conf/domain_conf.c                        | 28 +++++++++++++

>  src/conf/domain_conf.h                        | 10 +++++

>  src/libvirt_private.syms                      |  2 +

>  ...virtio-non-transitional.x86_64-latest.args | 34 +++++++++++++++

>  .../virtio-non-transitional.xml               | 26 ++++++++++++

>  .../virtio-transitional.x86_64-latest.args    | 34 +++++++++++++++

>  .../qemuxml2argvdata/virtio-transitional.xml  | 26 ++++++++++++

>  tests/qemuxml2argvtest.c                      |  3 ++

>  .../virtio-non-transitional.xml               | 42 +++++++++++++++++++

>  .../virtio-transitional.xml                   | 42 +++++++++++++++++++

>  tests/qemuxml2xmltest.c                       |  3 ++

>  13 files changed, 266 insertions(+)

>  create mode 100644 tests/qemuxml2argvdata/virtio-non-transitional.x86_64-latest.args

>  create mode 100644 tests/qemuxml2argvdata/virtio-non-transitional.xml

>  create mode 100644 tests/qemuxml2argvdata/virtio-transitional.x86_64-latest.args

>  create mode 100644 tests/qemuxml2argvdata/virtio-transitional.xml

>  create mode 100644 tests/qemuxml2xmloutdata/virtio-non-transitional.xml

>  create mode 100644 tests/qemuxml2xmloutdata/virtio-transitional.xml

> 

> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in

> index 7f07bb7f55..5220e19417 100644

> --- a/docs/formatdomain.html.in

> +++ b/docs/formatdomain.html.in

> @@ -2922,6 +2922,14 @@

>              <span class="since">Since 0.1.4</span>

>              </p>

>              </dd>

> +          <dt><code>model</code></dt>

> +            <dd>

> +            Indicates the emulated device model of the disk. Typically

> +            this is indicated solely by the <code>bus</code> property but

> +            for <code>bus</code> "virtio" the model can be specified further

> +            with "virtio-transitional" or "virtio-non-transitional"

> +            <span class="since">Since 5.1.0</span>


We should note that this is *only* valid when using a <adress type=pci>
because  the virtio-*ccw and virtio-*mmio don't support these.

In fact I wonder if that's good a reason to call them

  "virtio-pci-transitional" and "virtio-pci-non-transitional"



Regards,
Daniel
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Andrea Bolognani Jan. 15, 2019, 4:55 p.m. | #2
On Sun, 2019-01-13 at 18:12 -0500, Cole Robinson wrote:
[...]
> @@ -5431,6 +5436,16 @@ virDomainDiskDefValidate(const virDomainDiskDef *disk)

>          return -1;

>      }

>  

> +    if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO &&

> +        (disk->model == VIR_DOMAIN_DISK_MODEL_VIRTIO_TRANSITIONAL ||

> +         disk->model == VIR_DOMAIN_DISK_MODEL_VIRTIO_NON_TRANSITIONAL)) {

> +        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,

> +                       _("disk model '%s' only supported for bus '%s'"),

> +                       virDomainDiskModelTypeToString(disk->model),

> +                       virDomainDiskBusTypeToString(disk->bus));


s/only supported/not supported/

I also wonder if more thorough validation would be a good idea: this
only ensures that VIR_DOMAIN_DISK_MODEL_VIRTIO_* can't be used with
other bus types, but if later on we add more VIR_DOMAIN_DISK_MODEL_*
we won't be protected against those being use with
VIR_DOMAIN_DISK_BUS_VIRTIO...

[...]
> +typedef enum {

> +    VIR_DOMAIN_DISK_MODEL_DEFAULT = 0,

> +    VIR_DOMAIN_DISK_MODEL_VIRTIO_TRANSITIONAL,

> +    VIR_DOMAIN_DISK_MODEL_VIRTIO_NON_TRANSITIONAL,

> +

> +    VIR_DOMAIN_DISK_MODEL_LAST

> +} virDomainDiskModel;


I think we want to have VIR_DOMAIN_DISK_MODEL_VIRTIO as well, for
consistency's sake if nothing else.

For all other devices, model='virtio' will be (or already is) a
perfectly valid configuration, so not accepting it for disks would
violate the principle of least surprise.

[...]
> +++ b/tests/qemuxml2argvdata/virtio-non-transitional.xml

> @@ -0,0 +1,26 @@

> +<domain type='qemu'>

> +  <name>QEMUGuest1</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='q35'>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>

> +    <disk type='block' device='disk' model='virtio-non-transitional'>

> +      <driver name='qemu' type='raw'/>

> +      <source dev='/dev/HostVG/QEMUGuest1'/>

> +      <target dev='vda' bus='virtio'/>

> +    </disk>

> +    <controller type='usb' index='0' model='none'/>

> +    <input type='mouse' bus='ps2'/>

> +    <input type='keyboard' bus='ps2'/>

> +    <memballoon model='none'/>

> +  </devices>

> +</domain>


You can strip this file further by removing the <currentMemory>,
<os><boot>, <clock>, <on_*> and <input> elements at least.

-- 
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Daniel P. Berrangé Jan. 15, 2019, 5 p.m. | #3
On Tue, Jan 15, 2019 at 04:51:39PM +0000, Daniel P. Berrangé wrote:
> On Sun, Jan 13, 2019 at 06:12:05PM -0500, Cole Robinson wrote:
> > <disk> devices lack the model= attribute which is used by
> > most other device types. bus= mostly acts as one, but it
> > serves other purposes too like determing what target=
> > prefix to use, and for matching against controller type=
> > values.
> > 
> > Extending bus= to handle additional virtio transitional
> > devices will complicate apps lives, and it isn't a clean
> > mapping anyways. So let's bite the bullet and add a new
> > <disk model=X/> attribute, and wire up common handling
> > for virtio-{non-}transitional
> > 
> > Signed-off-by: Cole Robinson <crobinso@redhat.com>
> > ---
> >  docs/formatdomain.html.in                     |  8 ++++
> >  docs/schemas/domaincommon.rng                 |  8 ++++
> >  src/conf/domain_conf.c                        | 28 +++++++++++++
> >  src/conf/domain_conf.h                        | 10 +++++
> >  src/libvirt_private.syms                      |  2 +
> >  ...virtio-non-transitional.x86_64-latest.args | 34 +++++++++++++++
> >  .../virtio-non-transitional.xml               | 26 ++++++++++++
> >  .../virtio-transitional.x86_64-latest.args    | 34 +++++++++++++++
> >  .../qemuxml2argvdata/virtio-transitional.xml  | 26 ++++++++++++
> >  tests/qemuxml2argvtest.c                      |  3 ++
> >  .../virtio-non-transitional.xml               | 42 +++++++++++++++++++
> >  .../virtio-transitional.xml                   | 42 +++++++++++++++++++
> >  tests/qemuxml2xmltest.c                       |  3 ++
> >  13 files changed, 266 insertions(+)
> >  create mode 100644 tests/qemuxml2argvdata/virtio-non-transitional.x86_64-latest.args
> >  create mode 100644 tests/qemuxml2argvdata/virtio-non-transitional.xml
> >  create mode 100644 tests/qemuxml2argvdata/virtio-transitional.x86_64-latest.args
> >  create mode 100644 tests/qemuxml2argvdata/virtio-transitional.xml
> >  create mode 100644 tests/qemuxml2xmloutdata/virtio-non-transitional.xml
> >  create mode 100644 tests/qemuxml2xmloutdata/virtio-transitional.xml
> > 
> > diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> > index 7f07bb7f55..5220e19417 100644
> > --- a/docs/formatdomain.html.in
> > +++ b/docs/formatdomain.html.in
> > @@ -2922,6 +2922,14 @@
> >              <span class="since">Since 0.1.4</span>
> >              </p>
> >              </dd>
> > +          <dt><code>model</code></dt>
> > +            <dd>
> > +            Indicates the emulated device model of the disk. Typically
> > +            this is indicated solely by the <code>bus</code> property but
> > +            for <code>bus</code> "virtio" the model can be specified further
> > +            with "virtio-transitional" or "virtio-non-transitional"
> > +            <span class="since">Since 5.1.0</span>
> 
> We should note that this is *only* valid when using a <adress type=pci>
> because  the virtio-*ccw and virtio-*mmio don't support these.
> 
> In fact I wonder if that's good a reason to call them
> 
>   "virtio-pci-transitional" and "virtio-pci-non-transitional"

The patch 6 made me re-consider whether this is good or not, as for other
existing devices we generally auto-add -pci -ccw or -mmio as needed.

Perhaps just using documentation is sufficient.

Regards,
Daniel

Patch

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 7f07bb7f55..5220e19417 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -2922,6 +2922,14 @@ 
             <span class="since">Since 0.1.4</span>
             </p>
             </dd>
+          <dt><code>model</code></dt>
+            <dd>
+            Indicates the emulated device model of the disk. Typically
+            this is indicated solely by the <code>bus</code> property but
+            for <code>bus</code> "virtio" the model can be specified further
+            with "virtio-transitional" or "virtio-non-transitional"
+            <span class="since">Since 5.1.0</span>
+            </dd>
           <dt><code>rawio</code></dt>
             <dd>
             Indicates whether the disk needs rawio capability. Valid
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index aa50eac424..425d7f851a 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -1506,6 +1506,14 @@ 
           </interleave>
         </group>
       </choice>
+      <optional>
+        <attribute name="model">
+          <choice>
+            <value>virtio-transitional</value>
+            <value>virtio-non-transitional</value>
+          </choice>
+        </attribute>
+      </optional>
       <optional>
         <ref name="snapshot"/>
       </optional>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 222bb8c482..f847fb0487 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -889,6 +889,11 @@  VIR_ENUM_IMPL(virDomainDiskDetectZeroes, VIR_DOMAIN_DISK_DETECT_ZEROES_LAST,
               "on",
               "unmap")
 
+VIR_ENUM_IMPL(virDomainDiskModel, VIR_DOMAIN_DISK_MODEL_LAST,
+              "default",
+              "virtio-transitional",
+              "virtio-non-transitional")
+
 VIR_ENUM_IMPL(virDomainDiskMirrorState, VIR_DOMAIN_DISK_MIRROR_STATE_LAST,
               "none",
               "yes",
@@ -5431,6 +5436,16 @@  virDomainDiskDefValidate(const virDomainDiskDef *disk)
         return -1;
     }
 
+    if (disk->bus != VIR_DOMAIN_DISK_BUS_VIRTIO &&
+        (disk->model == VIR_DOMAIN_DISK_MODEL_VIRTIO_TRANSITIONAL ||
+         disk->model == VIR_DOMAIN_DISK_MODEL_VIRTIO_NON_TRANSITIONAL)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("disk model '%s' only supported for bus '%s'"),
+                       virDomainDiskModelTypeToString(disk->model),
+                       virDomainDiskBusTypeToString(disk->bus));
+        return -1;
+    }
+
     return 0;
 }
 
@@ -9518,6 +9533,14 @@  virDomainDiskDefParseXML(virDomainXMLOptionPtr xmlopt,
     }
     VIR_FREE(tmp);
 
+    if ((tmp = virXMLPropString(node, "model")) &&
+        (def->model = virDomainDiskModelTypeFromString(tmp)) < 0) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                       _("unknown disk model '%s'"), tmp);
+        goto error;
+    }
+    VIR_FREE(tmp);
+
     snapshot = virXMLPropString(node, "snapshot");
 
     rawio = virXMLPropString(node, "rawio");
@@ -24311,6 +24334,11 @@  virDomainDiskDefFormat(virBufferPtr buf,
     virBufferAsprintf(buf,
                       "<disk type='%s' device='%s'",
                       type, device);
+    if (def->model) {
+        virBufferAsprintf(buf, " model='%s'",
+                          virDomainDiskModelTypeToString(def->model));
+    }
+
     if (def->rawio) {
         virBufferAsprintf(buf, " rawio='%s'",
                           virTristateBoolTypeToString(def->rawio));
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index fae130668f..0c1879da0f 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -567,6 +567,14 @@  typedef enum {
     VIR_DOMAIN_DISK_DETECT_ZEROES_LAST
 } virDomainDiskDetectZeroes;
 
+typedef enum {
+    VIR_DOMAIN_DISK_MODEL_DEFAULT = 0,
+    VIR_DOMAIN_DISK_MODEL_VIRTIO_TRANSITIONAL,
+    VIR_DOMAIN_DISK_MODEL_VIRTIO_NON_TRANSITIONAL,
+
+    VIR_DOMAIN_DISK_MODEL_LAST
+} virDomainDiskModel;
+
 typedef struct _virDomainBlockIoTuneInfo virDomainBlockIoTuneInfo;
 struct _virDomainBlockIoTuneInfo {
     unsigned long long total_bytes_sec;
@@ -674,6 +682,7 @@  struct _virDomainDiskDef {
     int detect_zeroes; /* enum virDomainDiskDetectZeroes */
     char *domain_name; /* backend domain name */
     unsigned int queues;
+    int model; /* enum virDomainDiskModel */
     virDomainVirtioOptionsPtr virtio;
 };
 
@@ -3408,6 +3417,7 @@  VIR_ENUM_DECL(virDomainDeviceSGIO)
 VIR_ENUM_DECL(virDomainDiskTray)
 VIR_ENUM_DECL(virDomainDiskDiscard)
 VIR_ENUM_DECL(virDomainDiskDetectZeroes)
+VIR_ENUM_DECL(virDomainDiskModel)
 VIR_ENUM_DECL(virDomainDiskMirrorState)
 VIR_ENUM_DECL(virDomainController)
 VIR_ENUM_DECL(virDomainControllerModelPCI)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index c3d6306809..0d6f054cf2 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -343,6 +343,8 @@  virDomainDiskIoTypeFromString;
 virDomainDiskIoTypeToString;
 virDomainDiskMirrorStateTypeFromString;
 virDomainDiskMirrorStateTypeToString;
+virDomainDiskModelTypeFromString;
+virDomainDiskModelTypeToString;
 virDomainDiskPathByName;
 virDomainDiskRemove;
 virDomainDiskRemoveByName;
diff --git a/tests/qemuxml2argvdata/virtio-non-transitional.x86_64-latest.args b/tests/qemuxml2argvdata/virtio-non-transitional.x86_64-latest.args
new file mode 100644
index 0000000000..070b4b8334
--- /dev/null
+++ b/tests/qemuxml2argvdata/virtio-non-transitional.x86_64-latest.args
@@ -0,0 +1,34 @@ 
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+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 q35,accel=tcg,usb=off,dump-guest-core=off \
+-m 214 \
+-realtime mlock=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 pcie-root-port,port=0x8,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,\
+addr=0x1 \
+-device pcie-root-port,port=0x9,chassis=2,id=pci.2,bus=pcie.0,addr=0x1.0x1 \
+-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-virtio-disk0 \
+-device virtio-blk-pci,scsi=off,bus=pci.1,addr=0x0,drive=drive-virtio-disk0,\
+id=virtio-disk0,bootindex=1 \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
+resourcecontrol=deny \
+-msg timestamp=on
diff --git a/tests/qemuxml2argvdata/virtio-non-transitional.xml b/tests/qemuxml2argvdata/virtio-non-transitional.xml
new file mode 100644
index 0000000000..2b9b82f473
--- /dev/null
+++ b/tests/qemuxml2argvdata/virtio-non-transitional.xml
@@ -0,0 +1,26 @@ 
+<domain type='qemu'>
+  <name>QEMUGuest1</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='q35'>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>
+    <disk type='block' device='disk' model='virtio-non-transitional'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='vda' bus='virtio'/>
+    </disk>
+    <controller type='usb' index='0' model='none'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/virtio-transitional.x86_64-latest.args b/tests/qemuxml2argvdata/virtio-transitional.x86_64-latest.args
new file mode 100644
index 0000000000..070b4b8334
--- /dev/null
+++ b/tests/qemuxml2argvdata/virtio-transitional.x86_64-latest.args
@@ -0,0 +1,34 @@ 
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+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 q35,accel=tcg,usb=off,dump-guest-core=off \
+-m 214 \
+-realtime mlock=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 pcie-root-port,port=0x8,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,\
+addr=0x1 \
+-device pcie-root-port,port=0x9,chassis=2,id=pci.2,bus=pcie.0,addr=0x1.0x1 \
+-drive file=/dev/HostVG/QEMUGuest1,format=raw,if=none,id=drive-virtio-disk0 \
+-device virtio-blk-pci,scsi=off,bus=pci.1,addr=0x0,drive=drive-virtio-disk0,\
+id=virtio-disk0,bootindex=1 \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,\
+resourcecontrol=deny \
+-msg timestamp=on
diff --git a/tests/qemuxml2argvdata/virtio-transitional.xml b/tests/qemuxml2argvdata/virtio-transitional.xml
new file mode 100644
index 0000000000..c6b3fca760
--- /dev/null
+++ b/tests/qemuxml2argvdata/virtio-transitional.xml
@@ -0,0 +1,26 @@ 
+<domain type='qemu'>
+  <name>QEMUGuest1</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='q35'>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>
+    <disk type='block' device='disk' model='virtio-transitional'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='vda' bus='virtio'/>
+    </disk>
+    <controller type='usb' index='0' model='none'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 2cb8860d26..b365b89ae9 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -3068,6 +3068,9 @@  mymain(void)
     DO_TEST("riscv64-virt",
             QEMU_CAPS_DEVICE_VIRTIO_MMIO);
 
+    DO_TEST_CAPS_LATEST("virtio-transitional");
+    DO_TEST_CAPS_LATEST("virtio-non-transitional");
+
     /* Simple headless guests for various architectures */
     DO_TEST_CAPS_ARCH_LATEST("aarch64-virt-headless", "aarch64");
     DO_TEST_CAPS_ARCH_LATEST("ppc64-pseries-headless", "ppc64");
diff --git a/tests/qemuxml2xmloutdata/virtio-non-transitional.xml b/tests/qemuxml2xmloutdata/virtio-non-transitional.xml
new file mode 100644
index 0000000000..1c00365edf
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/virtio-non-transitional.xml
@@ -0,0 +1,42 @@ 
+<domain type='qemu'>
+  <name>QEMUGuest1</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-q35-4.0'>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='block' device='disk' model='virtio-non-transitional'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='vda' bus='virtio'/>
+      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
+    </disk>
+    <controller type='usb' index='0' model='none'/>
+    <controller type='sata' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
+    </controller>
+    <controller type='pci' index='0' model='pcie-root'/>
+    <controller type='pci' index='1' model='pcie-root-port'>
+      <model name='pcie-root-port'/>
+      <target chassis='1' port='0x8'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' multifunction='on'/>
+    </controller>
+    <controller type='pci' index='2' model='pcie-root-port'>
+      <model name='pcie-root-port'/>
+      <target chassis='2' port='0x9'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2xmloutdata/virtio-transitional.xml b/tests/qemuxml2xmloutdata/virtio-transitional.xml
new file mode 100644
index 0000000000..87d8ff4a25
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/virtio-transitional.xml
@@ -0,0 +1,42 @@ 
+<domain type='qemu'>
+  <name>QEMUGuest1</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-q35-4.0'>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='block' device='disk' model='virtio-transitional'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='vda' bus='virtio'/>
+      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
+    </disk>
+    <controller type='usb' index='0' model='none'/>
+    <controller type='sata' index='0'>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
+    </controller>
+    <controller type='pci' index='0' model='pcie-root'/>
+    <controller type='pci' index='1' model='pcie-root-port'>
+      <model name='pcie-root-port'/>
+      <target chassis='1' port='0x8'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' multifunction='on'/>
+    </controller>
+    <controller type='pci' index='2' model='pcie-root-port'>
+      <model name='pcie-root-port'/>
+      <target chassis='2' port='0x9'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
+    </controller>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index b686a585e8..febe3df286 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -1292,6 +1292,9 @@  mymain(void)
     DO_TEST("riscv64-virt",
             QEMU_CAPS_DEVICE_VIRTIO_MMIO);
 
+    DO_TEST_CAPS("virtio-transitional", "x86_64", "4.0.0");
+    DO_TEST_CAPS("virtio-non-transitional", "x86_64", "4.0.0");
+
     if (getenv("LIBVIRT_SKIP_CLEANUP") == NULL)
         virFileDeleteTree(fakerootdir);