Consider the following XML snippets:
$ cat scsicontroller.xml
<controller type='scsi' model='virtio-scsi' index='0'/>
$ cat scsihostdev.xml
<hostdev mode='subsystem' type='scsi'>
<source>
<adapter name='scsi_host0'/>
<address bus='0' target='8' unit='1074151456'/>
</source>
</hostdev>
If we create a guest that includes the contents of scsihostdev.xml,
but forget the virtio-scsi controller described in scsicontroller.xml,
one is silently created for us. The same holds true when attaching
a hostdev before the matching virtio-scsi controller.
(See qemuDomainFindOrCreateSCSIDiskController for context.)
Detaching the hostdev, followed by the controller, works well and the
guest behaves appropriately.
If we detach the virtio-scsi controller device first, any associated
hostdevs are detached for us by the underlying virtio-scsi code (this
is fine, since the connection is broken). But all is not well, as the
guest is unable to receive new virtio-scsi devices (the attach commands
succeed, but devices never appear within the guest), nor even be
shutdown, after this point.
While this is not libvirt's problem, we can prevent falling into this
scenario by checking if a controller is being used by any hostdev
devices. The same is already done for disk elements today.
Applying this patch and then using the XML snippets from earlier:
$ virsh detach-device guest_01 scsicontroller.xml
error: Failed to detach device from scsicontroller.xml
error: operation failed: device cannot be detached: device is busy
$ virsh detach-device guest_01 scsihostdev.xml
Device detached successfully
$ virsh detach-device guest_01 scsicontroller.xml
Device detached successfully
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
With the QEMU components in place, provide the XML parsing to
invoke that code when given the following XML snippet:
<hostdev mode='subsystem' type='scsi_host'>
<source protocol='vhost' wwpn='naa.501234567890abcd'/>
</hostdev>
An optional address element can be specified within the hostdev
(pick CCW or PCI as necessary):
<address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0625'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
Add basic vhost-scsi tests which were cloned from hostdev-scsi-virtio-scsi
in both xml2argv and xml2xml. Added ones for both vhost-scsi-ccw and
vhost-scsi-pci since the syntaxes are slightly different between them.
Also adjusted the docs to describe the changes.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Adjust the device string that is built for vhost-scsi devices so that it
can be invoked from hotplug.
From the QEMU command line, the file descriptors are expect to be numeric only.
However, for hotplug, the file descriptors are expected to begin with at least
one alphabetic character else this error occurs:
# virsh attach-device guest_0001 ~/vhost.xml
error: Failed to attach device from /root/vhost.xml
error: internal error: unable to execute QEMU command 'getfd':
Parameter 'fdname' expects a name not starting with a digit
We also close the file descriptor in this case, so that shutting down the
guest cleans up the host cgroup entries and allows future guests to use
vhost-scsi devices. (Otherwise the guest will silently end.)
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Open /dev/vhost-scsi, and record the resulting file descriptor, so that
the guest has access to the host device outside of the libvirt daemon.
Pass this information, along with data parsed from the XML file, to build
a device string for the qemu command line. That device string will be
for either a vhost-scsi-ccw device in the case of an s390 machine, or
vhost-scsi-pci for any others.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
For a new hostdev type='scsi_host' we have a number of
required functions for managing, adding, and removing the
host device to/from guests. Provide the basic infrastructure
for these tasks.
The name "SCSIVHost" (and its variants) is chosen to avoid
conflicts with existing code named "SCSIHost" to refer to
a hostdev type='scsi' protcol='none'.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
We already have a "scsi" hostdev subsys type, which refers to a single
LUN that is passed through to a guest. But what of things where
multiple LUNs are passed through via a single SCSI HBA, such as with
the vhost-scsi target? Create a new hostdev subsys type that will
carry this.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Do all the stuff for the vhost-scsi capability in QEMU,
so it's in place for our checks later.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
The type='scsi' parameter of an address element is ignored
if placed within a hostdev section, and rejected by the XML
schema used by virt-xml-validate. Remove it from the doc,
and correct a typo in the remaining address arguments.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Reviewed-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Defining a domain with a SCSI disk attached via a hostdev
tag and a source address unit value longer than two digits
causes an error when editing the domain with virsh edit,
even if no changes are made to the domain definition.
The error suggests invalid XML, somewhere:
# virsh edit lmb_guest
error: XML document failed to validate against schema:
Unable to validate doc against /usr/local/share/libvirt/schemas/domain.rng
Extra element devices in interleave
Element domain failed to validate content
The virt-xml-validate tool fails with a similar error:
# virt-xml-validate lmb_guest.xml
Relax-NG validity error : Extra element devices in interleave
lmb_guest.xml:17: element devices: Relax-NG validity error :
Element domain failed to validate content
lmb_guest.xml fails to validate
The hostdev tag requires a source address to be specified,
which includes bus, target, and unit address attributes.
According to the SCSI Architecture Model spec (section
4.9 of SAM-2), a LUN address is 64 bits and thus could be
up to 20 decimal digits long. Unfortunately, the XML
schema limits this string to just two digits. Similarly,
the target field can be up to 32 bits in length, which
would be 10 decimal digits.
# lsscsi -xx
[0:0:19:0x4022401100000000] disk IBM 2107900 3.44 /dev/sda
# lsscsi
[0:0:19:1074872354]disk IBM 2107900 3.44 /dev/sda
# cat lmb_guest.xml
<domain type='kvm'>
<name>lmb_guest</name>
<memory unit='MiB'>1024</memory>
...trimmed...
<devices>
<controller type='scsi' model='virtio-scsi' index='0'/>
<hostdev mode='subsystem' type='scsi'>
<source>
<adapter name='scsi_host0'/>
<address bus='0' target='19' unit='1074872354'/>
</source>
</hostdev>
...trimmed...
Since the reference unit and target fields are used in
several places in the XML schema, create a separate one
specific for SCSI Logical Units that will permit the
greater length. This permits both the validation utility
and the virsh edit command to succeed when a hostdev
tag is included.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Reviewed-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
The SCSI Architecture Model defines a logical unit address
as 64-bits in length, so change the field accordingly so
that the entire value could be stored.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
The address elements are all unsigned integers, so we should
use the appropriate print directive when printing it.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
The SCSI address element attributes bus, target, and unit are expected
to be positive values, so make sure no one provides a negative value since
the value is stored as an unsigned.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
If a SCSI hostdev is included in an initial domain XML, without a
corresponding controller statement, one is created silently when the
guest is booted.
When hotplugging a SCSI hostdev, a presumption is that the controller
is already present in the domain either from the original XML, or via
an earlier hotplug.
[root@xxxxxxxx ~]# cat disk.xml
<hostdev mode='subsystem' type='scsi'>
<source>
<adapter name='scsi_host0'/>
<address bus='0' target='3' unit='1088438288'/>
</source>
</hostdev>
[root@xxxxxxxx ~]# virsh attach-device guest01 disk.xml
error: Failed to attach device from disk.xml
error: internal error: unable to execute QEMU command 'device_add': Bus 'scsi0.0' not found
Since the infrastructure is in place, we can also create a controller
silently for use by the hotplugged hostdev device.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
For systems without a PCI bus, attaching a SCSI controller fails:
[root@xxxxxxxx ~]# cat controller.xml
<controller type='scsi' model='virtio-scsi' index='0' />
[root@xxxxxxxx ~]# virsh attach-device guest01 controller.xml
error: Failed to attach device from controller.xml
error: XML error: No PCI buses available
A similar problem occurs with the detach of a controller:
[root@xxxxxxxx ~]# virsh detach-device guest01 controller.xml
error: Failed to detach device from controller.xml
error: operation failed: controller scsi:0 not found
The qemuDomainXXtachPciControllerDevice routines made assumptions
that any caller had a PCI bus. These routines now selectively calls
PCI functions where necessary, and assigns the device information
type to one appropriate for the bus in use.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
For attach/detach of controller devices, we rename the functions to
remove 'PCI' from their title. The actual separation of PCI-specific
operations will be handled in the next patch.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Hotplugging a single SCSI device works, but adding additional ones
result in an error from QEMU:
[root@gpok197 ~]# virsh attach-device guest01 blah.xml
Device attached successfully
[root@gpok197 ~]# virsh attach-device guest01 blah2.xml
error: Failed to attach device from blah2.xml
error: internal error unable to execute QEMU command 'device_add': Duplicate ID 'hostdev0' for device
The hostdev ID that is created is always set to zero, regardless
of the contents of the XML. Changing the index in the hotplug case
to a negative one so the next available index is used.
Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Eric Farman