In case abi-dumper is available the stubdom builds will fail due to a
false dependency on dynamic loadable libraries. Fix that.
Fixes: d7c9f7a7a3 ("tools/libs: Write out an ABI analysis when abi-dumper is available")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Switch the used Mini-OS commit to 9f09744aa3e5982 in xen-unstable.
[ 9f09744aa3e5982 is current mini-os.git#master -iwj. ]
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
In case a domain is created with a cpupool other than Pool-0 specified
it will be moved to that cpupool before any vcpus are allocated.
This will lead to a NULL pointer dereference in sched_move_domain().
Fix that by tolerating vcpus not being allocated yet.
Fixes: 70fadc4163 ("xen/cpupool: support moving domain between cpupools with different granularity")
Reported-by: Bertrand Marquis <bertrand.marquis@arm.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
With smt=0 during a suspend/resume cycle of the machine the threads
which have been parked before will briefly come up again. This can
result in problems e.g. with cpufreq driver being active as this will
call into get_cpu_idle_time() for a cpu without initialized scheduler
data.
Fix that by letting get_cpu_idle_time() deal with this case. Drop a
redundant check in exchange.
Fixes: 132cbe8f35 ("sched: fix get_cpu_idle_time() with core scheduling")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>
I have touched most of the Xen libraries in the past, and there is a
clear lack of reviewer band width in the tools area.
Add myself as a tools/libs reviewer for that reason.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
The reasoning for commit 7bd8989ab7 ("tools/libs/guest: fix max_pfn
setting in map_p2m()") was wrong.
The max_pfn field in shared_info is misnamed, it has the semantics of
num_pfns, which is hidden at least partially in Linux, as the kernel is
(wrongly) treating it like the highest used pfn in some places.
So revert above commit.
Fixes: 7bd8989ab7 ("tools/libs/guest: fix max_pfn setting in map_p2m()")
Signed-off-by: Juergen Gross <jgross@suse.com>
There are some internals in the libxenstore interface which should be
removed.
Move those functions into xs_lib.c and the related definitions into
xs_lib.h. Remove the functions from the mapfile. Add xs_lib.o to
xenstore_client as some of the internal functions are needed there.
Bump the libxenstore version to 4.0 as the change is incompatible.
Note that the removed functions should not result in any problem as
they ought to be used by xenstored or xenstore_client only.
Avoid an enum as part of a structure as the size of an enum is
compiler implementation dependent.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
After 32-bit PV-guests have been security de-supported when not running
under PV-shim, the hypervisor will no longer be configured to support
those domains per default when not being built as PV-shim.
Unfortunately libxenguest will fail saving or restoring a PV domain
due to this restriction, as it is trying to get the compat MFN list
even for 64 bit guests.
Fix that by obtaining the compat MFN list only for 32-bit PV guests.
Fixes: 1a0f2fe229 ("SUPPORT.md: Un-shimmed 32-bit PV guests are no longer supported")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
There are some definitions which are used in libxenguest only now.
Move them from libxenctrl over to libxenguest.
Remove an unused macro.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The functionality in xc_core* should be part of libxenguest instead
of libxenctrl. Users are already either in libxenguest, or in xl.
There is one single exception: xc_core_arch_auto_translated_physmap()
is being used by xc_domain_memory_mapping(), which is used by qemu.
So leave the xc_core_arch_auto_translated_physmap() functionality in
libxenctrl.
This will make it easier to merge common functionality of xc_core*
and xg_sr_save*.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The guest suspend functionality is already part of libxenguest. Move
the resume functionality from libxenctrl to libxenguest, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Instead of open coding the mapping of the p2m list use the already
existing xc_core_arch_map_p2m() call, especially as the current code
does not support guests with the linear p2m map. It should be noted
that this code is needed for colo/remus only.
Switching to xc_core_arch_map_p2m() drops the need to bail out for
bitness of tool stack and guest differing.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
The core of a pv linux guest produced via "xl dump-core" is nor usable
as since kernel 4.14 only the linear p2m table is kept if Xen indicates
it is supporting that. Unfortunately xc_core_arch_map_p2m() is still
supporting the 3-level p2m tree only.
Fix that by copying the functionality of map_p2m() from libxenguest to
libxenctrl.
Additionally the mapped p2m isn't of a fixed length now, so the
interface to the mapping functions needs to be adapted. In order not to
add even more parameters, expand struct domain_info_context and use a
pointer to that as a parameter.
Fixes: dc6d609371 ("libxc: set flag for support of linear p2m list in domain builder")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
When setting the highest pfn used in the guest, don't subtract 1 from
the value read from the shared_info data. The value read already is
the correct pfn.
Fixes: 91e204d37f ("libxc: try to find last used pfn when migrating")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The main loop of xenstored is rather complicated due to different
handling of socket and ring-page interfaces. Unify that handling by
introducing interface type specific functions can_read() and
can_write().
Take the opportunity to remove the empty list check before calling
write_messages() because the function is already able to cope with an
empty list.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Put the interface type specific functions into an own structure and let
struct connection contain only a pointer to that new function vector.
Don't even define the socket based functions in case of NO_SOCKETS
(Mini-OS).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The Makefile of xenstore and related to that the global .gitignore
file contain some leftovers from ancient times. Remove those.
While at it sort the tools/xenstore/* entries in .gitignore.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add a new RING_RESPONSE_PROD_OVERFLOW() macro for being able to
detect an ill-behaved backend tampering with the response producer
index.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
As I have contributed all the code for hypfs, it would be natural to
be the maintainer.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
libxl_domain_resume() won't work correctly for the case it was called
due to a "xl save -c" command, i.e. to continue the suspended domain.
The information to do that is not saved in libxl__dm_resume_state for
non-HVM domains.
Fixes: 6298f0eb8f ("libxl: Re-introduce libxl__domain_resume")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Wei Liu <wl@xen.org>
When splitting libxl into libs/light and libs/util the related
MAINTAINERS entry was modified in a wrong way.
Reported-by: Jan Beulich <jbeulich@suse.com>
Fixes: 032a96e5ef ("maintainers: fix libxl paths")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
There is a very unlikely use after free bug and a memory leak in
live_update_start() of xenstore_control. Fix those.
Coverity-Id: 1472399
Fixes: 7f97193e6a ("tools/xenstore: add live update command to xenstore-control")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
When the host crashes it would sometimes be nice to have additional
debug data available which could be produced via debug keys, but
halting the server for manual intervention might be impossible due to
the need to reboot/kexec rather sooner than later.
Add support for automatic debug key actions in case of crashes which
can be activated via boot- or runtime-parameter.
Depending on the type of crash the desired data might be different, so
support different settings for the possible types of crashes.
The parameter is "crash-debug" with the following syntax:
crash-debug-<type>=<string>
with <type> being one of:
panic, hwdom, watchdog, kexeccmd, debugkey
and <string> a sequence of debug key characters with '+' having the
special semantics of a 10 millisecond pause.
So "crash-debug-watchdog=0+0qr" would result in special output in case
of watchdog triggered crash (dom0 state, 10 ms pause, dom0 state,
domain info, run queues).
Don't call key handlers in early boot, as some (e.g. for 'd') require
some initializations to be finished, like scheduler or idle domain.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
There are only two keyhandlers which make use of the cpu_user_regs
struct passed to them. In order to be able to call any keyhandler in
non-interrupt contexts, too, modify those two handlers to cope with a
NULL regs pointer by using run_in_exception_handler() in that case.
Suggested-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add support to run a function in an exception handler for Arm. Do it
as on x86 via a bug_frame, but pass the function pointer via a
register.
This needs to be done that way because GCC will not allow to use
"i" when PIE is enabled (Xen doesn't set the flag but instead rely on
the default value from the compiler).
Use the same BUGFRAME_* #defines as on x86 in order to make a future
common header file more easily achievable.
Signed-off-by: Juergen Gross <jgross@suse.com>
[ julien: Add more details on the issue between "i" and -fpie ]
Acked-by: Julien GralL <jgrall@amazon.com>
Commit 7f97193e6a ("tools/xenstore: add live update command to
xenstore-control") introduced testing an unsigned value to be less
than 0. Fix that.
Fixes: 7f97193e6a ("tools/xenstore: add live update command to xenstore-control")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Make /cpupool/<id>/sched-gran in hypfs writable. This will enable per
cpupool selectable scheduling granularity.
Writing this node is allowed only with no cpu assigned to the cpupool.
Allowed are values "cpu", "core" and "socket".
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Add a "sched-gran" entry to the per-cpupool hypfs directories.
For now make this entry read-only and let it contain one of the
strings "cpu", "core" or "socket".
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Add /cpupool/<cpupool-id> directories to hypfs. Those are completely
dynamic, so the related hypfs access functions need to be implemented.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Add some helpers to hypfs.c to support dynamic directories with a
numerical id as name.
The dynamic directory is based on a template specified by the user
allowing to use specific access functions and having a predefined
set of entries in the directory.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add a HYPFS_VARDIR_INIT() macro for initializing such a directory
statically, taking a struct hypfs_funcs pointer as parameter additional
to those of HYPFS_DIR_INIT().
Modify HYPFS_VARSIZE_INIT() to take the function vector pointer as an
additional parameter as this will be needed for dynamical entries.
For being able to let the generic hypfs coding continue to work on
normal struct hypfs_entry entities even for dynamical nodes add some
infrastructure for allocating a working area for the current hypfs
request in order to store needed information for traversing the tree.
This area is anchored in a percpu pointer and can be retrieved by any
level of the dynamic entries. The normal way to handle allocation and
freeing is to allocate the data in the enter() callback of a node and
to free it in the related exit() callback.
Add a hypfs_add_dyndir() function for adding a dynamic directory
template to the tree, which is needed for having the correct reference
to its position in hypfs.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add activation of the new binary for live update. The daemon case is
handled completely, while for stubdom we only add stubs.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Add reading the watch state records for live update.
This requires factoring out some of the add watch functionality into a
dedicated function.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Wei Liu <wl@xen.org>
Add the needed functions for reading node state for live update.
This requires some refactoring of current node handling in Xenstore in
order to avoid repeating the same code patterns multiple times.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
Add the needed functions for reading connection state for live update.
As the connection is identified by a unique connection id in the state
records we need to add this to struct connection. Add a new function
to return the connection based on a connection id.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
When started due to a live upgrade read the internal state and apply
it to the data base and internal structures.
Add the main control functions for that.
For now only handle the daemon case.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
In the live update case several initialization steps of xenstore must
be omitted or modified. Add the proper handling for that.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
For live update the functionality to introduce a new domain similar to
the XS_INTRODUCE command is needed, so split that functionality off
into a dedicated function introduce_domain().
Switch initial dom0 initialization to use this function, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
For support of live update the locally used files need to have the
"close on exec" flag set. Fortunately the used Xen libraries are
already doing this, so only the logging and tdb related files and
pipes are affected. openlog() has the close on exec attribute, too.
In order to be able to keep the event channels open specify the
XENEVTCHN_NO_CLOEXEC flag when calling xenevtchn_open().
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <julien.grall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
Dump the complete Xenstore status to a file (daemon case) or memory
(stubdom case).
As we don't know the exact length of the needed area in advance we are
using an anonymous rather large mapping in stubdom case, which will
use only virtual address space until accessed. And as we are writing
the area in a sequential manner this is fine. As the initial size we
are choosing the double size of the memory allocated via talloc(),
which should be more than enough.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
Add an include file containing all structures and defines needed for
dumping and restoring the internal Xenstore state.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
In order to simplify live update state dumping only allow live update
to happen when no transaction is active.
A timeout is used to detect guests which have a transaction active for
longer periods of time. In case such a guest is detected when trying
to do a live update it will be reported and the update will fail.
The admin can then either use a longer timeout, or use the force flag
to just ignore the transactions of such a guest, or kill the guest
before retrying.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Add the main framework for executing the live update. This for now
only defines the basic execution steps with empty dummy functions.
This final step returning means failure, as in case of success the
new executable will have taken over.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Today a Xenstore request is processed as soon as it is seen by
xenstored. Add the framework for being able to delay processing of a
request if the right conditions aren't met.
Any delayed requests are executed at the end of the main processing
loop in xenstored. They can either delay themselves again or just do
their job. In order to enable the possibility of a timeout, the main
loop will be paused for max one second if any requests are delayed.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Updating an instance of Xenstore via live update needs to hand over
the command line parameters to the updated instance. Those can be
either the parameters used by the updated instance or new ones when
supplied when starting the live update.
So when supplied store the new command line parameters in lu_status.
As it is related add a new option -U (or --live-update") to the command
line of xenstored which will be added when starting the new instance.
This enables to perform slightly different initializations when
started as a result of live update.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Wei Liu <wl@xen.org>
Save the new binary name for the daemon case and the new kernel for
stubdom in order to support live update of Xenstore..
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>
Live update of Xenstore is done in multiple steps. It needs a status
block holding the current state of live update and related data. It
is allocated as child of the connection live update was started over
in order to abort live update in case the connection is closed.
Allocation of the block is done in lu_binary[_alloc](), freeing in
lu_abort() (and for now in lu_start() as long as no real live-update
is happening).
Add tests in all live-update command handlers other than lu_abort()
and lu_binary[_alloc]() for being started via the same connection
as the begin of live-update.
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>
Add the basic parts for parsing the live-update control command.
For now only add the parameter evaluation and calling appropriate
functions. Those function only print a message for now and return
success.
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>
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>
In order to allow control commands with binary data refactor handling
of XS_CONTROL:
- get primary command first
- add maximum number of additional parameters to pass to command
handler
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Wei Liu <wl@xen.org>
Reading a gzipped string value from hypfs doesn't add a 0 byte at the
end. Fix that.
Fixes: 86234eafb9 ("libs: add libxenhypfs")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
For live update of Xenstore some records defined in the migration
stream document need to be changed:
- Support of the read-only socket has been dropped from all Xenstore
implementations, so ro-socket-fd in the global record can be removed.
- Some guests require the event channel to Xenstore to remain the same
on Xenstore side, so Xenstore has to keep the event channel interface
open across a live update. For this purpose an evtchn-fd needs to be
added to the global record.
- With no read-only support the flags field in the connection record
can be dropped.
- The evtchn field in the connection record needs to be switched to
hold the port of the Xenstore side of the event channel.
- A flags field needs to be added to permission specifiers in order to
be able to mark a permission as stale (XSA-322).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today the file descriptor for the access of the event channel driver
is being closed in case of exec(2). For the support of live update of
a daemon using libxenevtchn this can be problematic, so add a way to
keep that file descriptor open.
Add support of a flag XENEVTCHN_NO_CLOEXEC for xenevtchn_open() which
will result in _not_ setting O_CLOEXEC when opening the event channel
driver node.
The caller can then obtain the file descriptor via xenevtchn_fd().
Add an alternative open function xenevtchn_fdopen() which takes that
file descriptor as an additional parameter. This allows to allocate a
xenevtchn_handle and to associate it with that file descriptor.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Propagate the flags parameter of xenevtchn_open() to the OS-specific
handlers in order to enable handling them there.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Refuse a call of xenevtchn_open() with unsupported bits in flags being
set.
This will change behavior for callers passing junk in flags today,
but those would otherwise get probably unwanted side effects when the
flags they specify today get any meaning. So checking flags is the
right thing to do.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Rename the xenevtchn_open() parameter open_flags to flags as it might
be used for things not passed on to open().
No functional change.
No API/ABI changes.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
There is a mixture of different styles in libxenevtchn. Use the
standard xen style only.
No functional change.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
In order to better support resource allocation and locking for dynamic
hypfs nodes add enter() and exit() callbacks to struct hypfs_funcs.
The enter() callback is called when entering a node during hypfs user
actions (traversing, reading or writing it), while the exit() callback
is called when leaving a node (accessing another node at the same or a
higher directory level, or when returning to the user).
For avoiding recursion this requires a parent pointer in each node.
Let the enter() callback return the entry address which is stored as
the last accessed node in order to be able to use a template entry for
that purpose in case of dynamic entries.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The node specific write functions take a void user address handle as
parameter. As a write won't change the user memory use a const_void
handle instead.
This requires a new macro for casting a guest handle to a const type.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
When moving a domain between cpupools with different scheduling
granularity the sched_units of the domain need to be adjusted.
Do that by allocating new sched_units and throwing away the old ones
in sched_move_domain().
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
domain->remote_port and restore_existing_connections() are useless and
can be removed.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
set_tdb_key() can be used by destroy_node(), too. So remove the static
attribute and move it to xenstored_core.c.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
When xenstored crashes due to an unrecoverable condition it is calling
either barf() or barf_perror() to issue a message and then exit().
Make sure the message is visible somewhere by using syslog()
additionally to xprintf(), as the latter will be visible only with
tracing active.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The different fixed limits for absolute and relative path lengths of
Xenstore nodes make it possible to create per-domain nodes via
absolute paths which are not accessible using relative paths, as the
two limits differ by 1024 characters.
Instead of this weird limits use only one limit, which applies to the
relative path length of per-domain nodes and to the absolute path
length of all other nodes. This means, the path length check is
applied to the path after removing a possible start of
"/local/domain/<n>/" with <n> being a domain id.
There has been the request to be able to limit the path lengths even
more, so an additional quota is added which can be applied to path
lengths. It is XENSTORE_REL_PATH_MAX (2048) per default, but can be
set to lower values. This is done via the new "-M" or "--path-max"
option when invoking xenstored.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
I have been the major contributor for C Xenstore the past few years.
Add me as a maintainer for tools/xenstore/.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
By setting a watch with a very large tag it is possible to trick
xenstored to send watch event messages exceeding the maximum allowed
payload size. This might in turn lead to a crash of xenstored as the
resulting error can cause dereferencing a NULL pointer in case there
is no active request being handled by the guest the watch event is
being sent to.
Fix that by just dropping such watch events. Additionally modify the
error handling to test the pointer to be not NULL before dereferencing
it.
This is XSA-324.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Access rights of Xenstore nodes are per domid. Unfortunately existing
granted access rights are not removed when a domain is being destroyed.
This means that a new domain created with the same domid will inherit
the access rights to Xenstore nodes from the previous domain(s) with
the same domid.
This can be avoided by adding a generation counter to each domain.
The generation counter of the domain is set to the global generation
counter when a domain structure is being allocated. When reading or
writing a node all permissions of domains which are younger than the
node itself are dropped. This is done by flagging the related entry
as invalid in order to avoid modifying permissions in a way the user
could detect.
A special case has to be considered: for a new domain the first
Xenstore entries are already written before the domain is officially
introduced in Xenstore. In order not to drop the permissions for the
new domain a domain struct is allocated even before introduction if
the hypervisor is aware of the domain. This requires adding another
bool "introduced" to struct domain in xenstored. In order to avoid
additional padding holes convert the shutdown flag to bool, too.
As verifying permissions has its price regarding runtime add a new
quota for limiting the number of permissions an unprivileged domain
can set for a node. The default for that new quota is 5.
This is part of XSA-322.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <julien@amazon.com>
Today watch events are sent regardless of the access rights of the
node the event is sent for. This enables any guest to e.g. setup a
watch for "/" in order to have a detailed record of all Xenstore
modifications.
Modify that by sending only watch events for nodes that the watcher
has a chance to see otherwise (either via direct reads or by querying
the children of a node). This includes cases where the visibility of
a node for a watcher is changing (permissions being removed).
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>
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>
There are several places in xenstored using a permission array and the
size of that array. Introduce a new struct node_perms containing both.
This is part of XSA-115.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Instead of firing all watches for removing a subtree in one go, do so
only when the related node is being removed.
The watches for the top-most node being removed include all watches
including that node, while watches for nodes below that are only fired
if they are matching exactly. This avoids firing any watch more than
once when removing a subtree.
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>
Today a Xenstore node is being removed by deleting it from the parent
first and then deleting itself and all its children. This results in
stale entries remaining in the data base in case e.g. a memory
allocation is failing during processing. This would result in the
rather strange behavior to be able to read a node (as its still in the
data base) while not being visible in the tree view of Xenstore.
Fix that by deleting the nodes from the leaf side instead of starting
at the root.
As fire_watches() is now called from _rm() the ctx parameter needs a
const attribute.
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>
The Xenstore command XS_IS_DOMAIN_INTRODUCED should be possible for
privileged domains only (the only user in the tree is the xenpaging
daemon).
Instead of having the privilege test for each command introduce a
per-command flag for that purpose.
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>
There is no path which allows to call check_event_node() without a
event name. So don't let the result depend on the name being NULL and
add an assert() covering that case.
Rename the function to check_special_event() to better match the
semantics.
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>
When a node creation fails the number of nodes of the domain should be
the same as before the failed node creation. In case of failure when
trying to create a node requiring to create one or more intermediate
nodes as well (e.g. when /a/b/c/d is to be created, but /a/b isn't
existing yet) it might happen that the number of nodes of the creating
domain is not reset to the value it had before.
So move the quota accounting out of construct_node() and into the node
write loop in create_node() in order to be able to undo the accounting
in case of an error in the intermediate node destructor.
This is part of XSA-115.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Julien Grall <jgrall@amazon.com>
Instead of ignoring the transaction id for XS_WATCH and XS_UNWATCH
commands as it is documented in docs/misc/xenstore.txt, it is tested
for validity today.
Really ignore the transaction id for XS_WATCH and XS_UNWATCH.
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>
An unprivileged user of Xenstore is not allowed to write nodes with a
size exceeding a global quota, while privileged users like dom0 are
allowed to write such nodes. The size of a node is the needed space
to store all node specific data, this includes the names of all
children of the node.
When deleting a node its parent has to be modified by removing the
name of the to be deleted child from it.
This results in the strange situation that an unprivileged owner of a
node might not succeed in deleting that node in case its parent is
exceeding the quota of that unprivileged user (it might have been
written by dom0), as the user is not allowed to write the updated
parent node.
Fix that by not checking the quota when writing a node for the
purpose of removing a child's name only.
The same applies to transaction handling: a node being read during a
transaction is written to the transaction specific area and it should
not be tested for exceeding the quota, as it might not be owned by
the reader and presumably the original write would have failed if the
node is owned by the reader.
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>
evtchn_fifo_set_pending() can be simplified a little bit. Especially
testing for the fifo control block to exist can be moved out of the
main if clause of the function enabling to avoid testing the LINKED bit
twice.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Instead of a pointer to an error variable as parameter just use
ERR_PTR() to return the cause of an error in cpupool_create().
This propagates to scheduler_alloc(), too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Instead of open coding something like a linked list just use the
available functionality from list.h.
The allocation of a new cpupool id is not aware of a possible wrap.
Fix that. We don't, however, consider the case of extremely many pools
(beyond 4 billion) as something which needs explicitly handling right
now. First and foremost there would need to be systems with 4 billion
CPUs to make this many pools a sensible thing to have.
While adding the required new include to private.h sort the includes.
Signed-off-by: From: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
The cpupool id is an unsigned value in the public interface header, so
there is no reason why it is a signed value in struct cpupool.
Switch it to unsigned int.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
A guest with memory < maxmem often can't be dumped via xl dump-core
without an error message today:
xc: info: exceeded nr_pages (262144) losing pages
In case the last page of the guest isn't allocated the loop in
xc_domain_dumpcore_via_callback() will always spit out this message,
as the number of already dumped pages is tested before the next page
is checked to be valid.
The guest's p2m_size might be lower than expected, so this should be
tested in order to avoid reading past the end of it.
The guest might use high bits in p2m entries to flag special cases like
foreign mappings. Entries with an MFN larger than the highest MFN of
the host should be skipped.
Signed-off-by: Juergen Gross <jgross@suse.com>
Add a getsize() function pointer to struct hypfs_funcs for being able
to have dynamically filled entries without the need to take the hypfs
lock each time the contents are being generated.
For directories add a findentry callback to the vector and modify
hypfs_get_entry_rel() to use it. For its non-directory node counterpart
introduce the so far unused and hence missing ENOTDIR error code.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Instead of handling all errors from hypfs_get_entry() as ENOENT pass
up the real error value via ERR_PTR().
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Move the function pointers currently stored in each hypfs node into a
dedicated structure in order to save some space for each node. This
will save even more space with additional callbacks added in future.
Provide some standard function vectors.
Instead of testing the write pointer to be not NULL provide a dummy
function just returning -EACCESS. ASSERT() all vector entries being
populated when adding a node. This avoids any potential problem (e.g.
pv domain privilege escalations) in case of calling a non populated
vector entry.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Common style is to include header files in alphabetical order. Sort the
#include statements in cpupool.c accordingly.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>
Even with storing the scheduling granularity in struct cpupool there
are still a few bits missing for being able to have cpupools with
different granularity (apart from the missing interface for setting
the individual granularities): the number of cpus in a scheduling
unit is always taken from the global sched_granularity variable.
So store the value in struct cpupool and use that instead of
sched_granularity.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
When a cpu is removed from a cpupool and added to the free cpus it
should be added to sched_res_mask, too.
The related removal from sched_res_mask in case of core scheduling
is already done in schedule_cpu_add().
As long as all cpupools share the same scheduling granularity there
is nothing going wrong with the missing addition, but this will change
when per-cpupool granularity is fully supported.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Two cpus entering evtchn_fifo_set_pending() for the same event channel
can race in case the first one gets interrupted after setting
EVTCHN_FIFO_PENDING and when the other one manages to set
EVTCHN_FIFO_LINKED before the first one is testing that bit. This can
lead to evtchn_check_pollers() being called before the event is put
properly into the queue, resulting eventually in the guest not seeing
the event pending and thus blocking forever afterwards.
Note that commit 5f2df45ead ("xen/evtchn: rework per event channel
lock") made the race just more obvious, while the fifo event channel
implementation had this race forever since the introduction and use of
per-channel locks, when an unmask operation was running in parallel with
an event channel send operation.
Using a spinlock for the per event channel lock had turned out
problematic due to some paths needing to take the lock are called with
interrupts off, so the lock would need to disable interrupts, which in
turn broke some use cases related to vm events.
For avoiding this race the queue locking in evtchn_fifo_set_pending()
needs to be reworked to cover the test of EVTCHN_FIFO_PENDING,
EVTCHN_FIFO_MASKED and EVTCHN_FIFO_LINKED, too. Additionally when an
event channel needs to change queues both queues need to be locked
initially, in order to avoid having a window with no lock held at all.
Reported-by: Jan Beulich <jbeulich@suse.com>
Fixes: 5f2df45ead ("xen/evtchn: rework per event channel lock")
Fixes: de6acb78bf ("evtchn: use a per-event channel lock for sending events")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
In order to avoid latent races when updating an event channel put
xen_consumer and pending fields in different bytes. This is no problem
right now, but especially the pending indicator isn't used only when
initializing an event channel (unlike xen_consumer), so any future
addition to this byte would need to be done with a potential race kept
in mind.
At the same time move some other fields around to have less implicit
paddings and to keep related fields more closely together.
Finally switch struct evtchn to no longer use fixed sized types where
not needed.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The queue for a fifo event is depending on the vcpu_id and the
priority of the event. When sending an event it might happen the
event needs to change queues and the old queue needs to be kept for
keeping the links between queue elements intact. For this purpose
the event channel contains last_priority and last_vcpu_id values
elements for being able to identify the old queue.
In order to avoid races always access last_priority and last_vcpu_id
with a single atomic operation avoiding any inconsistencies.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of using a softirq pci_serr_error() can use NMI continuation
for issuing an error message.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Instead of calling send_guest_vcpu_virq() from NMI context use the
NMI continuation framework for that purpose. This avoids taking locks
in NMI mode.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Actions in NMI context are rather limited as e.g. locking is rather
fragile.
Add a framework to continue processing in normal interrupt context
after leaving NMI processing.
This is done by a high priority interrupt vector triggered via a
self IPI from NMI context, which will then call the continuation
function specified during NMI handling.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
With the event channel lock no longer disabling interrupts commit
52e1fc47ab ("evtchn/Flask: pre-allocate node on send path") can
be reverted again.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Currently the lock for a single event channel needs to be taken with
interrupts off, which causes deadlocks in some cases.
Rework the per event channel lock to be non-blocking for the case of
sending an event and removing the need for disabling interrupts for
taking the lock.
The lock is needed for avoiding races between event channel state
changes (creation, closing, binding) against normal operations (set
pending, [un]masking, priority changes).
Use a rwlock, but with some restrictions:
- Changing the state of an event channel (creation, closing, binding)
needs to use write_lock(), with ASSERT()ing that the lock is taken as
writer only when the state of the event channel is either before or
after the locked region appropriate (either free or unbound).
- Sending an event needs to use read_trylock() mostly, in case of not
obtaining the lock the operation is omitted. This is needed as
sending an event can happen with interrupts off (at least in some
cases).
- Dumping the event channel state for debug purposes is using
read_trylock(), too, in order to avoid blocking in case the lock is
taken as writer for a long time.
- All other cases can use read_lock().
Fixes: e045199c7c ("evtchn: address races with evtchn_reset()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Libxl bitmap operations for single bits (test, set, reset) take the bit
number as a signed integer without testing the value to be larger than
0.
Correct that by adding the appropriate tests.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Juergen Gross