[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [PATCH v5 3/4] docs: Introduce xenstore paths for hotplug features

Without some indication from a guest it is not possible for a
toolstack to know whether instantiation of a new vbd or vif should
result in a new PV device of the appropriate type being brought online.
(In other words whether guest PV drivers are present and functioning).

This patch documents two paths which vif and vbd frontend drivers can
use to advertise their ability to respond to new vif or vbd

Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Keir Fraser <keir@xxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>

 - Clarify use of the hotplug feature paths

 - Drop HVM restriction
 docs/misc/xenstore-paths.markdown | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/docs/misc/xenstore-paths.markdown 
index b8788f2..624b7fd 100644
--- a/docs/misc/xenstore-paths.markdown
+++ b/docs/misc/xenstore-paths.markdown
@@ -409,6 +409,18 @@ A domain writable path. Available for arbitrary domain use.
 A domain may write information about installed PV drivers using
 paths of this form.
+#### ~/feature/hotplug/vif = ("0"|"1") [w]
+#### ~/feature/hotplug/vbd = ("0"|"1") [w]
+By setting these paths to "1" a guest can indicate to a toolstack
+that it is capable of responding immediately to instantiation of,
+respectively, new vif by bringing online a new PV network device or
+a new vbd by bringing online a new PV block device.
+If the guest sets this path to "0" then it is indicating that it is
+definitely unable to respond immediately and hence the toolstack should
+defer instantiaton to the next VM start. However, if the path is absent
+then the toolstack may attempt the operation.
 ### Paths private to the toolstack
 #### ~/device-model/$DOMID/state [w]

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.