[libvirt] [PATCHv2 9/9] qemu: log error when domain has an unsupported IDE controller

Laine Stump laine at laine.org
Thu May 14 19:36:29 UTC 2015

We have previously effectively ignored all <controller type='ide'>
elements in a domain definition.

On the i440fx-based machinetypes there is an IDE controller that is
included in the chipset and can't be removed (which is the ide
controller with index='0'>), so it makes sense to ignore that one
controller. However, if an i440fx domain definition has a 2nd
controller, nothing catches this error (unless you also have a disk
attached to it, in which case qemu will complain that you're trying to
use the ide controller named "ide1", which doesn't exist), and if any
other type of domain has even a single controller defined, it will be
incorrectly ignored.

Ignoring a bogus controller definition isn't such a big problem, as
long as an error is logged when any disk is attached to that
non-existent controller. But in the case of q35-based machinetypes,
the hardcoded id ("alias" in libvirt terms) of its builtin SATA
controller is "ide", which happens to be the same id as the builtin
IDE controller on i440fx machinetypes. So libvirt creates a
commandline believing that it is connecting the disk to the builtin
(but actually nonexistent) IDE controller, qemu thinks that libvirt
wanted that disk connected to the builtin SATA controller, and
everybody is happy.

Until you try to connect a 2nd disk to the IDE controller. Then qemu
will complain that you're trying to set unit=1 on a controller that
requires unit=0 (SATA controllers are organized differently than IDE

After this patch, if a domain has an IDE controller defined for a
machinetype that has no IDE controllers, libvirt will log an error
about the controller itself as it is building the qemu commandline
(rather than a (possible) error from qemu about disks attached to that
controller). This is done by adding IDE to the list of controller
types that are handled in the loop that creates controller command
strings in qemuBuildCommandline() (previously it would *always* skip
IDE controllers). Then qemuBuildControllerDevStr() is modified to log
an appropriate error in the case of IDE controllers.

In the future, if we add support for extra IDE controllers (piix3-ide
and/or piix4-ide) we can just add it into the IDE case in
qemuBuildControllerDevStr(). For now, nobody seems anxious to add
extra support for an aging and very slow controller, when there are so
many better options available.

Change from V1: (this is the bugfix part of 11/13 in V1)

* put the cleanup that had no functional change into a separate patch

* remove some of the text from the commit log (although not too much,
  because I think the history is important).

 src/qemu/qemu_command.c                            | 32 ++++++++++++++++++----
 .../qemuxml2argv-disk-blockio.args                 |  2 +-
 .../qemuxml2argvdata/qemuxml2argv-disk-blockio.xml |  1 -
 .../qemuxml2argv-disk-ide-drive-split.args         |  2 +-
 .../qemuxml2argv-disk-ide-drive-split.xml          |  1 -
 .../qemuxml2argv-disk-source-pool-mode.args        |  2 +-
 .../qemuxml2argv-disk-source-pool-mode.xml         |  1 -
 .../qemuxml2argv-disk-source-pool.args             |  2 +-
 .../qemuxml2argv-disk-source-pool.xml              |  1 -
 .../qemuxml2xmlout-disk-source-pool.xml            |  1 -
 10 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index fdd6a2e..2fa4c0d 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4599,11 +4599,25 @@ qemuBuildControllerDevStr(virDomainDefPtr domainDef,
-    /* We always get an IDE controller, whether we want it or not. */
+        /* Since we currently only support the integrated IDE controller
+         * on 440fx, if we ever get to here, it's because some other
+         * machinetype had an IDE controller specified, or a 440fx had
+         * multiple ide controllers.
+         */
+        if (qemuDomainMachineIsI440FX(domainDef))
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("Only a single IDE controller is unsupported "
+                             "for this machine type"));
+        else
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                           _("IDE controllers are unsupported for "
+                             "this QEMU binary or machine type"));
+        goto error;
-                       _("Unknown controller type: %s"),
+                       _("Unsupported controller type: %s"),
         goto error;
@@ -8629,20 +8643,21 @@ qemuBuildCommandLine(virConnectPtr conn,
          * List of controller types that we add commandline args for,
          * *in the order we want to add them*.
-         * We don't add an explicit IDE or FD controller because the
+         * We don't add an explicit FD controller because the
          * provided PIIX4 device already includes one. It isn't possible to
          * remove the PIIX4.
          * We don't add PCI/PCIe root controller either, because it's
          * implicit, but we do add PCI bridges and other PCI
          * controllers, so we leave that in to check each
-         * one. Likewise, we don't do anything for the primary SATA
-         * controller on q35, but we do add those beyond this one
-         * exception.
+         * one. Likewise, we don't do anything for the primary IDE
+         * controller on an i440fx machine or primary SATA on q35, but
+         * we do add those beyond these two exceptions.
@@ -9439,6 +9454,11 @@ qemuBuildCommandLine(virConnectPtr conn,
                     cont->idx == 0 && qemuDomainMachineIsQ35(def))
+                /* first IDE controller on i440fx machines is implicit */
+                if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_IDE &&
+                    cont->idx == 0 && qemuDomainMachineIsI440FX(def))
+                        continue;
                 if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB &&
                     cont->model == -1 &&
                     !qemuDomainMachineIsQ35(def) &&
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.args
index 33f8714..79af23d 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.args
@@ -6,4 +6,4 @@ LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
 -drive file=/tmp/idedisk.img,if=none,id=drive-ide0-0-2 \
 -device ide-hd,bus=ide.0,unit=2,drive=drive-ide0-0-2,id=ide0-0-2,\
 logical_block_size=512,physical_block_size=512 \
--device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.xml
index 52c9704..2b400c3 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-blockio.xml
@@ -27,7 +27,6 @@
     <controller type='usb' index='0'/>
     <controller type='ide' index='0'/>
-    <controller type='ide' index='1'/>
     <memballoon model='virtio'/>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.args
index 9ccdd5e..4fe04b3 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.args
@@ -5,4 +5,4 @@ LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \
 -device ide-cd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 \
 -drive file=/tmp/idedisk.img,if=none,id=drive-ide0-0-2 \
 -device ide-hd,bus=ide.0,unit=2,drive=drive-ide0-0-2,id=ide0-0-2 \
--device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.xml
index 21c285b..65c438b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-ide-drive-split.xml
@@ -26,7 +26,6 @@
     <controller type='usb' index='0'/>
     <controller type='ide' index='0'/>
-    <controller type='ide' index='1'/>
     <memballoon model='virtio'/>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.args
index 8f6a3dd..7556294 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.args
@@ -7,4 +7,4 @@ file=iscsi://iscsi.example.com:3260/demo-target/2,if=none,media=cdrom,id=drive-i
 -device ide-drive,bus=ide.0,unit=2,drive=drive-ide0-0-2,id=ide0-0-2 -drive \
 file=/tmp/idedisk.img,if=none,id=drive-ide0-0-3 -device \
 ide-drive,bus=ide.0,unit=3,drive=drive-ide0-0-3,id=ide0-0-3 -device \
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.xml
index c791717..dcab1e9 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool-mode.xml
@@ -41,7 +41,6 @@
     <controller type='usb' index='0'/>
     <controller type='ide' index='0'/>
-    <controller type='ide' index='1'/>
     <controller type='pci' index='0' model='pci-root'/>
     <memballoon model='virtio'/>
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.args
index 6b409b7..f930e46 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.args
@@ -7,4 +7,4 @@ if=none,media=cdrom,id=drive-ide0-1-0 -device \
 ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -drive \
 file=/tmp/idedisk.img,if=none,id=drive-ide0-0-2 -device \
 ide-drive,bus=ide.0,unit=2,drive=drive-ide0-0-2,id=ide0-0-2 -device \
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.xml
index ef095a0..19255c9 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-source-pool.xml
@@ -39,7 +39,6 @@
     <controller type='usb' index='0'/>
     <controller type='ide' index='0'/>
-    <controller type='ide' index='1'/>
     <controller type='pci' index='0' model='pci-root'/>
     <memballoon model='virtio'/>
diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-source-pool.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-source-pool.xml
index 31e4928..d3c8b69 100644
--- a/tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-source-pool.xml
+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-source-pool.xml
@@ -37,7 +37,6 @@
     <controller type='usb' index='0'/>
     <controller type='ide' index='0'/>
-    <controller type='ide' index='1'/>
     <controller type='pci' index='0' model='pci-root'/>
     <memballoon model='virtio'/>

More information about the libvir-list mailing list