In order to be able to use pkg-config for obtaining linker- and
compiler-flags provide a xenstore.pc file.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
As a memory report can now be triggered via XS_CONTROL support via
command line and signal handler is no longer needed. Remove it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Add a XS_CONTROL command to xenstored for doing a talloc report to a
file. Right now this is supported by specifying a command line option
when starting xenstored and sending a signal to the daemon to trigger
the report.
To dump the report to the standard log file call:
xenstore-control memreport
To dump the report to a new file call:
xenstore-control memreport <file>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Today Xenstore supports logging only if specified at start of the
Xenstore daemon. As it can't be disabled during runtime it is not
recommended to start xenstored with logging enabled.
Add support for switching logging on and off at runtime and to
specify a (new) logfile. This is done via the XS_CONTROL wire command
which can be sent with xenstore-control.
To switch logging on just use:
xenstore-control log on
To switch it off again:
xenstore-control log off
To specify a (new) logfile:
xenstore-control logfile <file>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
The Xenstore protocol supports the XS_CONTROL command for triggering
various actions in the Xenstore daemon. Enhance that support by using
a command table and adding a help function.
Support multiple control commands in the associated xenstore-control
program used to issue XS_CONTROL commands.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Move the XS_CONTROL handling of xenstored to a new source file
xenstored_control.c.
In order to avoid making get_string() in xenstored_core.c globally
visible use strlen() instead, which is save in this context due to
xs_count_strings() before returned a value > 1.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
In preparation to support other than pure debug functionality via the
Xenstore XS_DEBUG wire command rename it to XS_CONTROL and make
XS_DEBUG an alias of it.
Add an alias xs_control_command for the associated xs_debug_command,
too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
As 0 is a valid file descriptor testing a descriptor to be valid
should be done via >= 0 instead of > 0.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
XS_RESTRICT and the xenstore library function xs_restrict() have never
been usable in all configurations and there are no known users.
This functionality was thought to limit access rights of device models
to xenstore in order to avoid affecting other domains in case of a
security breech. Unfortunately XS_RESTRICT won't help as current
qemu is requiring access to dom0 only accessible xenstore paths to
work correctly. So this command is useless and should be removed.
In order to avoid problems in the future remove all support for
XS_RESTRICT from xenstore.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: David Scott <dave@recoil.org>
Today xenstored tries to open a tdb data base file on disk when it is
started. As this is problematic in most cases the scripts used to start
xenstored ensure xenstored won't find such a file in order to start
with an empty xenstore.
A tdb data base file can't be used to restore all Xenstore state as
e.g. Xenstore watches are not kept in the tdb data base. The file is
meant to be used for debugging purposes after a xenstored crash only.
Instead of opening a Xenstore data base file found on disk always start
with an empty data base. This will avoid problems in case someone is
testing multiple xenstored versions without rebooting (which is not
supported but helps debugging in some cases).
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Commit 9e49dcf67f ("xenstore: add per-node generation counter) changed
the TDB layout, which - in order to not break older xenstored running
on the same system - need to be accompanied by a version bump.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Commit d4016288ab ("xenstore: support XS_DIRECTORY_PART in
libxenstore") introduced a theoretical bug: the generation count of
the read node is transferred via strncpy without forcing a NUL byte
at the end. Correct this.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Instead of always allocating a data buffer for incoming or outgoing
xenstore wire data add a small buffer to the buffered_data structure
of xenstored. This has the advantage that especially sending simple
response messages like errors or "OK" will no longer need allocating
a data buffer. This requires adding a memory context where the
allocated buffer was used for that purpose.
In order to avoid allocating a new buffered_data structure for each
response reuse the structure of the original request. This in turn
will avoid any new memory allocations for sending e.g. an ENOMEM
response making it possible to send it at all. To do this the
allocation of the buffered_data structure for the incoming request
must be done when a new request is recognized instead of doing it
when accepting a new connect.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The xenstore wire command argument parsing of the different commands
is repeating some patterns multiple times. Add some helper functions
to avoid the duplicated code.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Move functions used in only one source to the file where they are used
and make them static.
Remove some prototypes from headers which are no longer in use.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Add a return value to all wire command functions of xenstored. If such
a function returns an error send the error message in
process_message().
Only code refactoring, no change in behavior expected.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Instead of switch() statements for selecting wire command actions use
an array for this purpose.
While doing this add the XS_RESTRICT type for diagnostic prints and
correct the printed string for XS_IS_DOMAIN_INTRODUCED.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
This will enable all users of libxenstore to handle xenstore nodes
with a huge amount of children.
In order to not depend completely on the XS_DIRECTORY_PART
functionality use it only in case of E2BIG returned by XS_DIRECTORY.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
As the payload size for one xenstore wire command is limited to 4096
bytes it is impossible to read the children names of a node with a
large number of children (e.g. /local/domain in case of a host with
more than about 2000 domains). This effectively limits the maximum
number of domains a host can support.
In order to support such long directory outputs add a new wire command
XS_DIRECTORY_PART which will return only some entries in each call and
can be called in a loop to get all entries.
Input data are the path of the node and the byte offset into the child
list where returned data should start.
Output is the generation count of the node (which will change each time
the node is being modified) and a list of child names starting with
the specified index. The end of the list is indicated by an empty
child name. It is the responsibility of the caller to check for data
consistency by comparing the generation counts of all returned data
sets to be the same for one node.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
In order to be able to support reading the list of a node's children in
multiple chunks (needed for list sizes > 4096 bytes) without having to
allocate a temporary buffer we need some kind of generation counter for
each node. This will help to recognize a node has changed between
reading two chunks.
As removing a node and reintroducing it must result in different
generation counts each generation value has to be globally unique. This
can be ensured only by using a global 64 bit counter.
For handling of transactions there is already such a counter available,
it just has to be expanded to 64 bits and must be stored in each
modified node.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
The layout of the tdb record of xenstored is defined at multiple
places: read_node(), write_node() and in xs_tdb_dump.c
Use a common structure instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Instead of calling add_change_node() at places where write_node() is
called, do that inside write_node().
Note that there is one case where add_change_node() is called now when
a later failure will prohibit the changed node to be written: in case
of a write_node failing due to an error in tdb_store(). As the only
visible change of behavior is a stale event fired for the node, while
the failing tdb_store() signals a corrupted xenstore database, the
stale event will be the least problem of this case.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
In order to prepare adding a generation count to each node modify
add_change_node() to take the connection pointer and a node pointer
instead of the transaction pointer and node name as parameters. This
requires moving the call of add_change_node() from do_rm() to
delete_node_single().
While at it correct the comment for the prototype: there is no
longjmp() involved.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
add_change_node() in xenstored is used to add a modified node to the
list of changed nodes of one transaction. It is being called with the
recurse parameter set to true when removing a node in order to get
watches for children of the node fired at transaction end, too.
If, however, the node to be deleted had been modified in the same
transaction the recurse parameter of add_change_node() is lost as
an entry already in the list of the changed nodes won't be entered
again.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
Blktap2 is effectively dead code for a few years.
Notable changes in this patch:
0. Unhook blktap2 from build system
1. Now libxl no longer supports TAP disk backend, appropriate assertions
are added and some code paths now return ERROR_FAIL
2. Tap is no longer a supported backend in doc
3. Remove relevant entries in MAINTAINERS
A patch to actually remove blktap2 directory will come later.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: George Dunlap <George.Dunlap@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
On a system with systemd the xenstore sockets are created via systemd.
Remove the related configuration files in order to be able to decide
at runtime whether the sockets should be created or not. This will
enable Xen to start xenstore either via a daemon or via a stub domain.
As the xenstore domain start program will exit after it has done its
job prepare the same behaviour to be tolerated by systemd for the
xenstore daemon by specifying the appropriate flags in the service
file.
A rerun of autogen.sh is required.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: David Scott <dave@recoil.org>
If memfile is NULL, the signal handler won't be installed, hence fopen
won't dereference NULL. Coverity is not smart enough to figure that out
unfortunately.
Add an assertion to prevent coverity from complaining.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
XenServer's coverity instance complains that a few lines below
create_node dereferences NULL if name == NULL. It however fails to
figure out that if node is NULL, errno won't be ENOENT, so do_mkdir
should have bailed before create_node.
That said, it would be good if we don't need to go through the hops. We
can bail earlier if name is NULL.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Add support for debugging memory allocation statistics to xenstored.
Specifying "-M <file>" on the command line will enable the feature.
Whenever xenstored receives SIGUSR1 it will dump out a full talloc
report to <file>. This helps finding e.g. memory leaks in xenstored.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Use a temporary memory context for memory allocations when firing
watches. This will avoid leaking memory in case of long living
connections and/or xenstore entries.
This requires adding a new parameter to fire_watches() and add_event()
to specify the memory context to use for allocations.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Add a parameter to xenstored get_node() function to explicitly
specify the memory context to be used for allocations. This will make
it easier to avoid memory leaks by using a context which is freed
soon.
This requires adding the temporary context to errno_from_parents() and
ask_parents(), too.
When calling get_node() select a sensible memory context for the new
parameter by preferring a temporary one.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Add a parameter to xenstored read_node() function to explicitly
specify the memory context to be used for allocations. This will make
it easier to avoid memory leaks by using a context which is freed
soon.
When calling read_node() select a sensible memory context for the new
parameter by preferring a temporary one.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Add a parameter to xenstored get_parent() function to explicitly
specify the memory context to be used for allocations. This will make
it easier to avoid memory leaks by using a context which is freed
soon.
When available use a temporary context when calling get_parent(),
otherwise mimic the old behavior by calling get_parent() with the same
argument for both parameters.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
In order to be able to avoid leaving temporary memory allocated after
processing of a command in xenstored call all command functions with
the temporary "in" context. Each function can then make use of that
temporary context for allocating temporary memory instead of either
leaving that memory allocated until the connection is dropped (or
even until end of xenstored) or freeing the memory itself.
This requires to modify the interfaces of the functions taking only
one argument from the connection by moving the call of onearg() into
the single functions. Other than that no functional change.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
xs_perm_to_string takes a size_t which isn't defined by anything
pulled in directly by this header.
Given the other headers xenstore_lib.h pulls in this looks to be an
oversight rather than a deliberate policy.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
libxenforeignmemory will provide a stable API and ABI for mapping
foreign domain memory (subject to appropriate privileges).
The new library exposes an interface equivalent to
xc_map_foreign_memory_bulk, which all the other
xc_map_foreign_memory_* functions (which remain in libxc) are
implemented in terms of.
Upon request (via #define XC_WANT_COMPAT_MAP_FOREIGN_API) libxenctrl
will provide a compat API for the old names. This is used by qemu-xen
and qemu-trad as well as various in tree things (which required
de-dupping various #includes in some too to get the #define before the
first).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- updated MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION ]
libxengnttab will provide a stable API and ABI for accessing the
grant table devices.
The functions are moved into the xengnt{tab,shr} namespace to make a
clean break from libxc and avoid ambiguity regarding which interfaces
are stable.
All in-tree users are updated to use the new names.
Upon request (via #define XC_WANT_COMPAT_GNTTAB_API) libxenctrl will
provide a compat API for the old names. This is used by qemu-xen for
the time being. qemu-xen-traditional is updated in lockstep.
This leaves a few grant table related functions which go via privcmd
(GNTTABOP) rather than ioctls on the /dev/xen/gnt* devices in
libxenctrl. Specifically:
- xc_gnttab_get_version
- xc_gnttab_map_table_v1
- xc_gnttab_map_table_v2
- xc_gnttab_op
These functions do not appear to be needed by qemu-dm, qemu-pv
(provision of device model to HVM guests and PV backends respectively)
or by libvchan suggesting they are not needed by non-toolstack uses of
event channels.
The new library uses a version script to ensure that only expected
symbols are exported and to version them such that ABI guarantees can
be kept in the future.
After this change libxenvchan no longer needs to link against
libxenctrl. It still needs xenctrl.h in one file for xen_mb and
friends.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
[ ijc -- updated MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION ]
libxenevtchn will provide a stable API and ABI for accessing the
evtchn device.
The functions are moved into the xenevtchn namespace to make a clean
break from libxc and avoid ambiguity regarding which interfaces are
stable.
All in-tree users are updated to use the new names.
Upon request (via #define XC_WANT_COMPAT_EVTCHN_API) libxenctrl will
provide a compat API for the old names. This is used by qemu-xen for
the time being. qemu-xen-traditional is updated in lockstep.
This leaves a few event channel related functions which go via privcmd
(EVTCHNOP) rather than ioctls on the /dev/xen/evtchn device in
libxenctrl. Specifically:
- xc_evtchn_alloc_unbound
- xc_evtchn_reset
- xc_evtchn_status
Note that xc_evtchn_alloc_unbound's functionality is also provided by
xenevtchn_bind_unbound_port() (née xc_evtchn_bind_unbound_port) and is
probably redundant.
These functions do not appear to be needed by qemu-dm, qemu-pv
(provision of device model to HVM guests and PV backends respectively)
or by libvchan suggesting they are not needed by non-toolstack uses of
event channels. QEMU does use these in hw/xenpv/xen_domainbuild.c but
that is a "toolstack use".
The new library uses a version script to ensure that only expected
symbols are exported and to version them such that ABI guarantees can
be kept in the future.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- updated MINIOS_UPSTREAM_REVISION and QEMU_TRADITIONAL_REVISION ]
The program init-xenstore-domain to start a xenstore domain instead
of the xenstored daemon is built, but not installed. Change that.
Move the program to a new tools subdirectory "helpers" to be able to
use libxl in a later patch. Otherwise a dependency loop will be
created.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
With the addition of HVMlite the hypervisor now always requires a non-null
arch domain config, which is different between HVM and PV guests.
Add a new parameter to xc_domain_create that contains a pointer to an arch
domain config. If the pointer is null, create a default arch domain config
based on guest type.
Fix all the in-tree callers to provide a null arch domain config in order to
mimic previous behaviour.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
With the addition of FMODE_ATOMIC_POS in the Linux 3.14 kernel,
concurrent blocking file accesses to a single open file descriptor can
cause a deadlock trying to grab the file position lock. If a watch has
been set up, causing a read_thread to blocking read on the file
descriptor, then future writes that would cause the background read to
complete will block waiting on the file position lock before they can
execute. This race condition only occurs when libxenstore is accessing
the xenstore daemon through the /proc/xen/xenbus file and not through
the unix domain socket, which is the case when the xenstore daemon is
running as a stub domain or when oxenstored is passed
--disable-socket. Accessing the daemon from the true character device
also does not exhibit this problem.
On Linux, prefer using the character device file over the proc file if
the character device exists.
Signed-off-by: Jonathan Creekmore <jonathan.creekmore@gmail.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
C requires that every use of va_copy() is matched with a va_end() call.
This is especially important for x86_64 as va_{start,copy}() may need to
allocate memory to generate a va_list containing parameters which were
previously in registers.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Juergen Gross
Olaf Hering
Wei Liu
Jan Beulich
Roger Pau Monne
Ian Campbell
Jonathan Creekmore
Andrew Cooper