Add saving the maximum values of the different accounting data seen
per domain and (for unprivileged domains) globally, and print those
values via the xenstore-control quota command. Add a sub-command for
resetting the global maximum values seen.
This should help for a decision how to set the related quotas.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In docs/misc/xenstore.txt the description of the Xenstore node access
permissions is missing one important aspect, which can be found only
in the code or in the wiki [1]:
The first permission entry is defining the owner of the node via the
domid, and the access rights for all domains NOT having a dedicated
permission entry.
Make that aspect clear in the official documentation.
[1]: https://wiki.xenproject.org/wiki/XenBus#Permissions
Reported-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Make the xenstored internal trace configurable by adding classes
which can be switched on and off independently from each other.
Define the following classes:
- obj: Creation and deletion of interesting "objects" (watch,
transaction, connection)
- io: incoming requests and outgoing responses
- wrl: write limiting
Per default "obj" and "io" are switched on.
Entries written via trace() will always be printed (if tracing is on
at all).
Add the capability to control the trace settings via the "log"
command and via a new "--log-control" command line option.
Add a missing trace_create() call for creating a transaction.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The permission scheme of Xenstore nodes is not really covered by
docs/misc/xenstore.txt, other than referring to the Xen wiki.
Add a paragraph explaining the permissions of nodes, and especially
mentioning removal of nodes when a domain has been removed from
Xenstore.
This is part of XSA-419.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add a xenstore-control command "quota" to:
- show current quota settings
- change quota settings
- show current quota related values of a domain
Note that in the case the new quota is lower than existing one,
Xenstored may continue to handle requests from a domain exceeding the
new limit (depends on which one has been broken) and the amount of
resource used will not change. However the domain will not be able to
create more resource (associated to the quota) until it is back to below
the limit.
This is part of XSA-326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add documentation for an extension of the WATCH command used to limit
the scope of watched paths. Additionally it enables to receive more
information in the events related to special watches (@introduceDomain
or @releaseDomain).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add documentation for two new Xenstore wire commands SET_QUOTA and
GET_QUOTA used to set or query the global Xenstore quota or those of
a given domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
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@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add documentation for an extension of the WATCH command used to limit
the scope of watched paths. Additionally it enables to receive more
information in the events related to special watches (@introduceDomain
or @releaseDomain).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Add documentation for two new Xenstore wire commands SET_QUOTA and
GET_QUOTA used to set or query the Xenstore quota of a given domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
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@suse.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Commit 13dd372834 removed the documentation for XS_RESUME, however
this command is still implemented (at least in C Xenstored) and used by
libxl when resuming a domain.
So re-instate the documentation for the XS_RESUME. Take the opportunity
to update it as there is a user of the command.
Fixes: 13dd372834 ("docs/designs: re-work the xenstore migration document...")
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>
Add the "live-update" command to xenstore-control enabling updating
xenstored to a new version in a running Xen system.
With -c <arg> it is possible to pass a different command line to the
new instance of xenstored. This will replace the command line used
for the invocation of the just running xenstored instance.
The running xenstored (or xenstore-stubdom) needs to support live
updating, of course.
For now just add a small dummy handler to C xenstore denying any
live update action.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
The special watches "@introduceDomain" and "@releaseDomain" should be
allowed for privileged callers only, as they allow to gain information
about presence of other guests on the host. So send watch events for
those watches via privileged connections only.
In order to allow for disaggregated setups where e.g. driver domains
need to make use of those special watches add support for calling
"set permissions" for those special nodes, too.
This is part of XSA-115.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
... to specify a separate migration stream that will also be suitable for
live update.
The original scope of the document was to support non-cooperative migration
of guests [1] but, since then, live update of xenstored has been brought into
scope. Thus it makes more sense to define a separate image format for
serializing xenstore state that is suitable for both purposes.
The document has been limited to specifying a new image format. The mechanism
for acquiring the image for live update or migration is not covered as that
is more appropriately dealt with by a patch to docs/misc/xenstore.txt. It is
also expected that, when the first implementation of live update or migration
making use of this specification is committed, that the document is moved from
docs/designs into docs/specs.
NOTE: It will only be necessary to save and restore state for active xenstore
connections, but the documentation for 'RESUME' in xenstore.txt implies
otherwise. That command is unused so this patch deletes it from the
specification.
[1] See https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/designs/non-cooperative-migration.md
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Change the url scheme to https. This is all in-tree references to the
Xen wiki.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
This patch details proposes extra migration data and xenstore protocol
extensions to support non-cooperative live migration of guests.
NOTE: doc/misc/xenstore.txt is also amended to replace the <mfn> term
for the INTRODUCE operation with the <gfn>, since this is what
it actually is.
Signed-off-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <jgrall@amazon.com>
The CONTROL command (former DEBUG command) isn't specified in the
xenstore protocol doc. Add it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Backport: 4.9+
DIRECTORY_PART was missing in docs/misc/xenstore.txt. Add it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
Backport: 4.9+
Jürgen Groß <jgross@suse.com> points out that this is entirely wrong.
Adding the "Backport" tag so we find this revert too.
This reverts commit d34dc88098.
Backport: 4.9+
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
... specification.
This was added by commit 0ca64ed8 "xenstore: add support for reading
directory with many children" but not added to the specification at that
point. A version of xenstored supporting the command was first released
in Xen 4.9.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Backport: 4.9+
docs/misc/xenstore.txt states that xenstored will use "0" as a valid
transaction id after 2^32 transactions. This is not true. Remove that
statement.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
I have confirmed that the relevant pages have been transitioned.
What remains is pages which have not yet been moved over:
$ rgrep xenwiki *
tools/libxen/README:http://wiki.xensource.com/xenwiki/XenApi
tools/xenballoon/xenballoond.README:http://wiki.xensource.com/xenwiki/Open_Topics_For_Discussion?action=AttachFile&do=get&target=Memory+Overcommit.pdf
Note that "PythonInXlConfig" never existed in the old wiki and does not exist
in the new. This reference was introduced by 22735:cb94dbe20f97 and was
supposed to have been written prior to the 4.1 release. I have transitioned it
anyway but it's not clear how valuable the message actually is. Perhaps we
should just remove that aspect of it?
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>
Acked-by: Ian Jackson <ian.jackson.citrix.com>
During kexec all old watches have to be removed, otherwise the new
kernel will receive unexpected events. Allow a guest to reset itself
and cleanup all of its watches and transactions.
Add a new XS_RESET_WATCHES command to do the reset on behalf of the
guest.
(Changes by iwj: specify the argument to be a single nul byte. Permit
read-only clients to use the new command.)
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
* Documents the existing 4kby size limit on xenstore message payloads
* Causes xs.c in libxenstore to fail locally rather than violating
said limit (which is good because xenstored kills the client
connection if it's exceeded).
* Introduces some limits on path lengths in xenstored. I trust
no-one is using path lengths >2kby. This is good because currently
a domain client can create a 4kby relative path that the dom0 tools
cannot access since they'd have to specify the somewhat longer
absolute path.
* Removes uses of the host's PATH_MAX (!)
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
The attached patch adds a new text file docs/misc/xenstore.txt which
describes the actual protocol implemented by xenstored. This was
reverse-engineered from the actual code in tools/xenstore.
I didn't bother making any automatic arrangements to ensure that the
implemented and documented protocols are kept in step (for example,
automatic code generation, etc.) The protocol is rather messy
unfortunately and unsuitable for an xdr approach, and in any case is
not likely to change very quickly.
Also in this patch are a couple of comments for xenstored_core.c which
help clarify the behaviour of some payload parsing helper functions.
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Juergen Gross
Jan Beulich
Julien Grall
Paul Durrant
Ian Jackson
Tim Deegan
Ian Campbell
Olaf Hering
Keir Fraser