On 04/23/2018 09:14 AM, Michal Privoznik wrote:
This is a definition that holds information on SCSI persistent reservation settings. The XML part looks like this:
<reservations enabled='yes' managed='no'> <source type='unix' path='/path/to/qemu-pr-helper.sock' mode='client'/> </reservations>
If @managed is set to 'yes' then the <source/> is not parsed. This design was agreed on here:
https://www.redhat.com/archives/libvir-list/2017-November/msg01005.html
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: John Ferlan <jferlan@redhat.com>
Even though this is present there's still an adjustment or two that needs to be made to formatdomain.html.in
--- docs/formatdomain.html.in | 23 +++- docs/schemas/domaincommon.rng | 34 +----- docs/schemas/storagecommon.rng | 50 ++++++++ src/conf/domain_conf.c | 38 ++++++ src/libvirt_private.syms | 3 + src/util/virstoragefile.c | 131 +++++++++++++++++++++ src/util/virstoragefile.h | 14 +++ .../disk-virtio-scsi-reservations.xml | 49 ++++++++ .../disk-virtio-scsi-reservations.xml | 1 + tests/qemuxml2xmltest.c | 2 + 10 files changed, 314 insertions(+), 31 deletions(-) create mode 100644 tests/qemuxml2argvdata/disk-virtio-scsi-reservations.xml create mode 120000 tests/qemuxml2xmloutdata/disk-virtio-scsi-reservations.xml
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index ada0df227f..6ed2fd349d 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -2565,7 +2565,10 @@ </disk> <disk type='block' device='lun'> <driver name='qemu' type='raw'/> - <source dev='/dev/sda'/> + <source dev='/dev/sda'> + <reservations enabled='yes' managed='no'> + <source type='unix' path='/path/to/qemu-pr-helper' mode='client'/> + </reservations> <target dev='sda' bus='scsi'/> <address type='drive' controller='0' bus='0' target='3' unit='0'/> </disk> @@ -2928,6 +2931,24 @@ <a href="formatstorageencryption.html">Storage Encryption</a> page for more information. </dd> + <dt><code>reservations</code></dt> + <dd><span class="since">Since libvirt 4.3.0</span>, the
4.4.0
+ <code>reservations</code> can be a sub-element of the> + <code>source</code> element for storage sources (QEM driver only).
QEMU
+ If present (and enabled) it enables persistent reservations for SCSI + based disks. The element has one mandatory attribute + <code>enabled</code> with accepted values <code>yes</code> and + <code>no</code>. If the feature is enabled, then there's another + mandatory attribute <code>managed</code> (accepted values are the + same as for <code>enabled</code>) that enables or disables libvirt + spawning a helper process. When the PR is unmanaged, then hypervisor + acts as a client and path to server socket must be provided in child + element <code>source</code>, which currently accepts only the + following attributes: <code>type</code> with one value + <code>unix</code>, <code>path</code> with path the socket, and + finally <code>mode</code> which accepts either <code>server</code> + or <code>client</code> and specifies the role of hypervisor.
I know I've pointed this out before - mode only accepts client. Yes the grammar supports both, but the code supports only one and that's all we should list.
+ </dd>
Can we squeeze in a (somewhat facetiously :-)): It's recommended to allow libvirt manage the persistent reservations. Or Please don't use unmanaged mode, it's going to be really painful for all involved ;-) John
</dl>
<p>