From: Paul Durrant Date: Tue, 17 Nov 2015 11:32:04 +0000 (+0000) Subject: docs: Introduce xenstore paths for hotplug features X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~2209 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=e8f98cb2d4112d08add03caecf9d53da7e92b6f3;p=xen.git 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 instantiations. Signed-off-by: Paul Durrant Cc: Ian Campbell Cc: Ian Jackson Cc: Jan Beulich Cc: Keir Fraser Cc: Tim Deegan Acked-by: Ian Jackson --- diff --git a/docs/misc/xenstore-paths.markdown b/docs/misc/xenstore-paths.markdown index b8788f26e4..624b7fd12e 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]