[PATCH v3 2/5] tools/xenstore: add documentation for new set/get-feature commands

[Juergen Gross <jgross@xxxxxxxx>]

Add documentation for two new Xenstore wire commands SET_FEATURE and
GET_FEATURE used to set or query the Xenstore features visible in the
ring page of a given domain.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V2:
- remove feature bit (Julien Grall)
- GET_FEATURE without domid will return Xenstore supported features
  (triggered by Julien Grall)
V3:
- clarify that guest only sees a copy of features (Julien Grall)
- add remark that SET_FEATURE will be rejected after INTRODUCE of a
  domain (Julien Grall)
---
 docs/misc/xenstore.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/docs/misc/xenstore.txt b/docs/misc/xenstore.txt
index a3d3da0a5b..9134cb7947 100644
--- a/docs/misc/xenstore.txt
+++ b/docs/misc/xenstore.txt
@@ -331,6 +331,23 @@ SET_TARGET         <domid>|<tdomid>|
 
        xenstored prevents the use of SET_TARGET other than by dom0.
 
+GET_FEATURE            [<domid>|]              <value>|
+SET_FEATURE            <domid>|<value>|
+       Returns or sets the contents of the "feature" field copied to
+       offset 2064 of the Xenstore ring page of the domain specified by
+       <domid>. <value> is a decimal number being a logical or of the
+       feature bits as defined in docs/misc/xenstore-ring.txt. Trying
+       to set a bit for a feature not being supported by the running
+       Xenstore will be denied. Providing no <domid> with the
+       GET_FEATURE command will return the features which are supported
+       by Xenstore.
+
+       SET_FEATURE for a domain will be rejected after the INTRODUCE
+       command for this domain has been sent to xenstored.
+
+       xenstored prevents the use of GET_FEATURE and SET_FEATURE other
+       than by dom0.
+
 ---------- Miscellaneous ----------
 
 CONTROL                        <command>|[<parameters>|]
-- 
2.35.3