[libvirt] PATCH: Support setting a disk drive serial (number)
Dave Allan
dallan at redhat.com
Mon Aug 17 18:37:48 UTC 2009
Daniel P. Berrange wrote:
> All hard disks (IDE, SCSI, USB, VirtIO) have a concept of a serial number
> which is intended to uniquely identify them. If you mean this off, QEMU
> just makes up a serial on the fly. THis is not guarenteed to be stable
> across guest reboots with hardware changes. It is thus desirable to be
> able to specify this in libvirt XML. To that end, this patch allows
> for a <serial> element inside a disk
>
> <disk type='file' device='disk'>
> <source file='/media/lacie-500-disk-2/virtual-machines/scratch5.img'/>
> <target dev='vda' bus='virtio'/>
> <serial>dan123virtio</serial>
> </disk>
>
> the contents is free-form. It implemenmts this for the QEMU driver for
> any disk using -drive style args. Unfortunately this excludes USB disk,
> even though internally QEMU can set a serial for these, the -usbdevice
> syntax does not allow it
>
> Daniel
>
> * docs/schemas/domain.rng: Add <serial> element to disks
> * src/domain_conf.h, src/domain_conf.c: XML parsing and
> formatting for disk serial numbers
> * src/qemu_conf.c: Set serial number when launching guests
> * tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.args,
> tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml: Add
> serial number to XML test
> ---
> docs/schemas/domain.rng | 10 ++++++++++
> src/domain_conf.c | 11 +++++++++++
> src/domain_conf.h | 1 +
> src/qemu_conf.c | 2 ++
> .../qemuxml2argv-disk-drive-shared.args | 2 +-
> .../qemuxml2argv-disk-drive-shared.xml | 1 +
> 6 files changed, 26 insertions(+), 1 deletions(-)
>
> diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng
> index f857301..16f35e4 100644
> --- a/docs/schemas/domain.rng
> +++ b/docs/schemas/domain.rng
> @@ -336,6 +336,11 @@
> <empty/>
> </element>
> </optional>
> + <optional>
> + <element name="serial">
> + <ref name="diskSerial"/>
> + </element>
> + </optional>
> </define>
> <!--
> A disk description can be either of type file or block
> @@ -1135,6 +1140,11 @@
> <param name="pattern">[A-Za-z0-9_\.\+\-&:/]+</param>
> </data>
> </define>
> + <define name="diskSerial">
> + <data type="string">
> + <param name="pattern">[A-Za-z0-9_\.\+\-]+</param>
> + </data>
> + </define>
> <define name="genericName">
> <data type="string">
> <param name="pattern">[a-zA-Z0-9_\+\-]+</param>
> diff --git a/src/domain_conf.c b/src/domain_conf.c
> index 1d2cc7c..654f753 100644
> --- a/src/domain_conf.c
> +++ b/src/domain_conf.c
> @@ -284,6 +284,7 @@ void virDomainDiskDefFree(virDomainDiskDefPtr def)
> if (!def)
> return;
>
> + VIR_FREE(def->serial);
> VIR_FREE(def->src);
> VIR_FREE(def->dst);
> VIR_FREE(def->driverName);
> @@ -661,6 +662,7 @@ virDomainDiskDefParseXML(virConnectPtr conn,
> char *bus = NULL;
> char *cachetag = NULL;
> char *devaddr = NULL;
> + char *serial = NULL;
>
> if (VIR_ALLOC(def) < 0) {
> virReportOOMError(conn);
> @@ -718,6 +720,9 @@ virDomainDiskDefParseXML(virConnectPtr conn,
> } else if ((flags & VIR_DOMAIN_XML_INTERNAL_STATUS) &&
> xmlStrEqual(cur->name, BAD_CAST "state")) {
> devaddr = virXMLPropString(cur, "devaddr");
> + } else if ((serial == NULL) &&
> + (xmlStrEqual(cur->name, BAD_CAST "serial"))) {
> + serial = (char *)xmlNodeGetContent(cur);
> }
> }
> cur = cur->next;
> @@ -836,6 +841,8 @@ virDomainDiskDefParseXML(virConnectPtr conn,
> driverName = NULL;
> def->driverType = driverType;
> driverType = NULL;
> + def->serial = serial;
> + serial = NULL;
>
> cleanup:
> VIR_FREE(bus);
> @@ -847,6 +854,7 @@ cleanup:
> VIR_FREE(driverName);
> VIR_FREE(cachetag);
> VIR_FREE(devaddr);
> + VIR_FREE(serial);
>
> return def;
>
> @@ -3519,6 +3527,9 @@ virDomainDiskDefFormat(virConnectPtr conn,
> virBufferAddLit(buf, " <readonly/>\n");
> if (def->shared)
> virBufferAddLit(buf, " <shareable/>\n");
> + if (def->serial)
> + virBufferEscapeString(buf, " <serial>%s</serial>\n",
> + def->serial);
>
> if (flags & VIR_DOMAIN_XML_INTERNAL_STATUS) {
> virBufferAddLit(buf, " <state");
> diff --git a/src/domain_conf.h b/src/domain_conf.h
> index 44302be..7bad5e7 100644
> --- a/src/domain_conf.h
> +++ b/src/domain_conf.h
> @@ -109,6 +109,7 @@ struct _virDomainDiskDef {
> char *dst;
> char *driverName;
> char *driverType;
> + char *serial;
> int cachemode;
> unsigned int readonly : 1;
> unsigned int shared : 1;
> diff --git a/src/qemu_conf.c b/src/qemu_conf.c
> index 082f107..95d41e6 100644
> --- a/src/qemu_conf.c
> +++ b/src/qemu_conf.c
> @@ -1748,6 +1748,8 @@ int qemudBuildCommandLine(virConnectPtr conn,
> if (disk->driverType &&
> qemuCmdFlags & QEMUD_CMD_FLAG_DRIVE_FORMAT)
> virBufferVSprintf(&opt, ",format=%s", disk->driverType);
> + if (disk->serial)
> + virBufferVSprintf(&opt, ",serial=%s", disk->serial);
>
> if (disk->cachemode) {
> const char *mode =
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.args
> index 611cd33..07cbe0e 100644
> --- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.args
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.args
> @@ -1 +1 @@
> -LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -drive file=/dev/HostVG/QEMUGuest1,if=ide,index=0,format=qcow2,cache=off -drive file=/dev/HostVG/QEMUGuest2,if=ide,media=cdrom,index=2,format=raw -net none -serial none -parallel none -usb
> +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait -no-acpi -boot c -drive file=/dev/HostVG/QEMUGuest1,if=ide,index=0,format=qcow2,serial=XYZXYZXYZYXXYZYZYXYZY,cache=off -drive file=/dev/HostVG/QEMUGuest2,if=ide,media=cdrom,index=2,format=raw -net none -serial none -parallel none -usb
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml
> index b386315..c4e4734 100644
> --- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-shared.xml
> @@ -19,6 +19,7 @@
> <source dev='/dev/HostVG/QEMUGuest1'/>
> <target dev='hda' bus='ide'/>
> <shareable/>
> + <serial>XYZXYZXYZYXXYZYZYXYZY</serial>
> </disk>
> <disk type='block' device='cdrom'>
> <driver name='qemu' type='raw'/>
This patch seems like a very good idea to me. I'm surprised it doesn't
cause more grief if the serial # keeps changing. I didn't review the
code too closely, but a definite ACK to the functionality, and I saw no
problems with the implementation in the quick look I took.
As a possible additional feature, in the case of an entire device being
assigned to the guest, have you considered passing through the serial of
the underlying device? The serial is available in the nodedev XML.
Dave
More information about the libvir-list
mailing list