In order to prepare the replacement of TDB with direct accessible nodes
in memory, remove the support for a file backed data base.
This allows to remove xs_tdb_dump, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The TODO file is not really helpful any longer. It contains only
entries which no longer apply or it is unknown what they are meant
for ("Dynamic/supply nodes", "Remove assumption that rename doesn't
fail").
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
There is no need to keep struct wrl_timestampt, as it serves the same
purpose as the more simple time base provided by get_now().
Move some more stuff from xenstored_domain.h into xenstored_domain.c
as it is being used nowhere else.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Some wrl_*() functions are only used in xenstored_domain.c, so make
them static. In order to avoid the need of forward declarations, move
the whole function block to the start of the file.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Today hashtable_insert() returns 0 in case of an error. Change that to
let it return an errno value in the error case and 0 in case of success.
In order to avoid any missed return value checks or related future
backport errors, rename hashtable_insert() to hashtable_add().
Even if not used today, do the same switch for the return value of
hashtable_expand().
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The minsize parameter of create_hashtable() doesn't have any real use
case for Xenstore, so drop it.
For better talloc_report_full() diagnostic output add a name parameter
to create_hashtable().
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Do the following cleanups:
- hashtable_count() isn't used at all, so remove it
- replace prime_table_length and max_load_factor with macros
- make hash() static
- add a loadlimit() helper function
- remove the /***/ lines between functions
- do some style corrections
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of having individual quota variables switch to a table based
approach like the generic accounting. Include all the related data in
the same table and add accessor functions.
This enables to use the command line --quota parameter for setting all
possible quota values, keeping the previous parameters for
compatibility.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Let get_optval_int() return an unsigned value and rename it
accordingly.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The maxrequests, node size, number of node permissions, and path length
quota are a little bit special, as they are either active in
transactions only (maxrequests), or they are just per item instead of
count values. Nevertheless being able to know the maximum number of
those quota related values per domain would be beneficial, so add them
to the generic accounting.
The per domain value will never show current numbers other than zero,
but the maximum number seen can be gathered the same way as the number
of nodes during a transaction.
To be able to use the const qualifier for a new function switch
domain_is_unprivileged() to take a const pointer, too.
For printing the quota/max values, adapt the print format string to
the longest quota name (now 17 characters long).
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
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>
As transaction accounting is active for unprivileged domains only, it
can easily be added to the generic per-domain accounting.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add a new trace switch "tdb" and the related trace calls.
The "tdb" switch is off per default.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add a new trace switch "acc" and the related trace calls.
The "acc" switch is off per default.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add the accounting of per-domain usage of Xenstore memory, watches, and
outstanding requests to the array based mechanism.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
In order to enable switching memory accounting to the generic array
based accounting, add the current connection to the parameters of
domain_memory_add().
This requires to add the connection to some other functions, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add the node accounting to the accounting information buffering in
order to avoid having to undo it in case of failure.
This requires to call domain_nbentry_dec() before any changes to the
data base, as it can return an error now.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Instead of modifying accounting data and undo those modifications in
case of an error during further processing, add a framework for
collecting the needed changes and commit them only when the whole
operation has succeeded.
This scheme can reuse large parts of the per transaction accounting.
The changed_domain handling can be reused, but the array size of the
accounting data should be possible to be different for both use cases.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Introduce the scheme of an accounting data array for per-domain
accounting data and use it initially for the number of nodes owned by
a domain.
Make the accounting data type to be unsigned int, as no data is allowed
to be negative at any time.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In order to prepare keeping accounting data in an array instead of
using independent fields, switch the struct changed_domain accounting
data to that scheme, for now only using an array with one element.
In order to be able to extend this scheme add the needed indexing enum
to xenstored_domain.h.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The accounting for the number of nodes of a domain in an active
transaction is not working correctly, as it is checking the node quota
only against the number of nodes outside the transaction.
This can result in the transaction finally failing, as node quota is
checked at the end of the transaction again.
On the other hand even in a transaction deleting many nodes, new nodes
might not be creatable, in case the node quota was already reached at
the start of the transaction.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
There is no need to have the Xenstore headers listed in the LIBS
section now that they have been added to the XENSTORE section.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
In xen/include/public/io/9pfs.h the name of the Xenstore backend node
"security-model" should be "security_model", as this is how the Xen
tools are creating it and qemu is reading it.
Fixes: ad58142e73 ("xen/public: move xenstore related doc into 9pfs.h")
Fixes: cf1d2d22fd ("docs/misc: Xen transport for 9pfs")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
In case XSM is active, the handling of XEN_SYSCTL_getdomaininfolist
can fail if the last domain scanned isn't allowed to be accessed by
the calling domain (i.e. xsm_getdomaininfo(XSM_HOOK, d) is failing).
Fix that by just ignoring scanned domains where xsm_getdomaininfo()
is returning an error, like it is effectively done when such a
situation occurs for a domain not being the last one scanned.
Fixes: d046f361dc ("Xen Security Modules: XSM")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Today it is not possible to analyse crash dumps of a system in
hypervisor mode when it had been booted via EFI, as the crash utility
doesn't understand the file format of xen.efi.
This can easily be solved by creating an ELF file from xen.efi via
objcopy. Using that file as name list for crash enables the user to
analyse the dump in hypervisor mode. Note that crash isn't happy with
a file containing no text and data, so using --only-keep-debug is not
an option.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Update the help text of the CONFIG_DEBUG_INFO option to be a little
bit more specific.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
In order to support hypervisor analysis of crash dumps, xen-syms needs
to contain debug_info. It should be allowed to configure the hypervisor
to be built with CONFIG_DEBUG_INFO in non-debug builds without having
to enable EXPERT.
Using a rather oldish gcc (7.5) it was verified that code generation
doesn't really differ between CONFIG_DEBUG_INFO on or off without
CONFIG_DEBUG being set (only observed differences were slightly
different symbol addresses, verified via "objdump -d", resulting from
the different config.gz in the binary). The old gcc version selection
was based on the assumption, that newer gcc won't regress in this
regard.
So move CONFIG_DEBUG_INFO out of the section guarded by EXPERT.
It should be mentioned that there have been reports that the linking
of the xen.efi might take considerably longer with CONFIG_DEBUG_INFO
selected when using newer binutils.
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Dietmar Hahn <dietmar.hahn@fujitsu.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Today when finalizing a transaction the number of node quota is checked
to not being exceeded after the transaction. This check is always done,
even if the transaction is being performed by a privileged connection,
or if there were no nodes created in the transaction.
Correct that by checking quota only if:
- the transaction is being performed by an unprivileged guest, and
- at least one node was created in the transaction
Reported-by: Julien Grall <julien@xen.org>
Fixes: f2bebf72c4 ("xenstore: rework of transaction handling")
Signed-off-by: Juergen Gross <jgross@suse.com>
There is a part of a comment in create_node() which should have been
deleted when modifying the related coding.
Fixes: 1cd3cc7ea2 ("tools/xenstore: create_node: Don't defer work to undo any changes on failure")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
vchan/init.c is defining offsetof privately. Remove that definition
and just use stddef.h instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
xfs/fsys_xfs.c is defining offsetof privately. Remove that definition
and just use stddef.h instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
util.h contains a definition of offsetof(), which isn't needed, as
firmware/include/stddef.h's doesn't really need overriding.
Remove it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Instead of having 3 identical copies of the definition of a
container_of() macro in different tools header files, add that macro
to xen-tools/common-macros.h and use that instead.
Delete the other copies of that macro.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Defining min(), min_t(), max() and max_t() at other places than
xen-tools/common-macros.h isn't needed, as the definitions in said
header can be used instead.
Same applies to BUILD_BUG_ON() in hvmloader.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Rework the config parsing of a p9 device to use the
split_string_into_pair() function instead of open coding it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Today split_string_into_pair() will not really do what its name is
suggesting: instead of splitting a string into a pair of strings using
a delimiter, it will return the first two strings of the initial string
by using the delimiter.
This is never what the callers want, so modify split_string_into_pair()
to split the string only at the first delimiter found, resulting in
something like "x=a=b" to be split into "x" and "a=b" when being called
with "=" as the delimiter. Today the returned strings would be "x" and
"a".
At the same time switch the delimiter from "const char *" (allowing
multiple delimiter characters) to "char" (a single character only), as
this makes the function more simple without breaking any use cases.
Suggested-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Instead of duplicating libxl__device_console_add() work in
init-xenstore-domain.c, just use libxenlight.
This requires to add a small wrapper function to libxenlight, as
libxl__device_console_add() is an internal function.
This at once removes a theoretical race between starting xenconsoled
and xenstore-stubdom, as the old code wasn't using a single
transaction for writing all the entries, leading to the possibility
that xenconsoled would see only some of the entries being written.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Most use cases of split_string_into_pair() are requiring the returned
strings to be white space trimmed.
In order to avoid the same code pattern multiple times, add a predicate
parameter to split_string_into_pair() which can be specified to call
trim() with that predicate for the string pair returned. Specifying
NULL for the predicate will avoid the call of trim().
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
In order to better reflect the contents of the header and to make it
more appropriate to use it for different runtime environments like
programs, libraries, and firmware, rename the libs.h include file to
common-macros.h. Additionally add a comment pointing out the need to be
self-contained.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> # tools/python/xen/lowlevel/xc/xc.c
Acked-by: Christian Lindig <christian.lindig@cloud.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
tools/tests/vhpet tests don't build since ages (at least since 4.10)
and they can't be activated from outside of tools/tests/vhpet.
Remove them as they seem to be irrelevant.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
The documented connection sequence in xen/include/public/io/9pfs.h has
a bug: the frontend needs to wait for the backend to have published its
features before being able to allocate its rings and event-channels.
While correcting that, make it clear that there might be multiple
rings and event-channels by adding "(s)".
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
In xen/include/public/io/9pfs.h the documentation regarding the
Xenstore entries isn't reflecting reality: the "tag" Xenstore entry
is on the frontend side, not on the backend one.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
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>
The current version is no longer 4.17-rc. Update it to "4.18-unstable".
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
When loading a Xenstore stubdom the loader doesn't know whether the
lo be loaded kernel is a PVH or a PV one. So it tries to load it as
a PVH one first, and if this fails it is loading it as a PV kernel.
This results in errors being logged in case the stubdom is a PV kernel.
Suppress those errors by setting the minimum logging level to
"critical" while trying to load the kernel as PVH.
In case PVH mode and PV mode loading fails, retry PVH mode loading
without changing the log level in order to get the error messages
logged.
Fixes: f89955449c ("tools/init-xenstore-domain: support xenstore pvh stubdom")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The Xenstore related documentation is currently to be found in
docs/misc/9pfs.pandoc, instead of the related header file
xen/include/public/io/9pfs.h like for most other paravirtualized
device protocols.
There is a comment in the header pointing at the document, but the
given file name is wrong. Additionally such headers are meant to be
copied into consuming projects (Linux kernel, qemu, etc.), so pointing
at a doc file in the Xen git repository isn't really helpful for the
consumers of the header.
This situation is far from ideal, which is already being proved by the
fact that neither qemu nor the Linux kernel are implementing the
device attach/detach protocol correctly.
Change that by moving the Xenstore related 9pfs documentation from
docs/misc/9pfs.pandoc into xen/include/public/io/9pfs.h.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Using a tab for separating the command from the options in the output
of "xenstore-control help" results in a rather ugly list.
Use a fixed size for the command instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today check_store() is only testing the correctness of the node tree.
Add verification of the accounting data (number of nodes) and correct
the data if it is wrong.
Do the initial check_store() call only after Xenstore entries of a
live update have been read. This is wanted to make sure the accounting
data is correct after a live update.
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>
Instead of using malloc() and friends, let the hashtable implementation
use the talloc framework.
This is more consistent with the rest of xenstored and it allows to
track memory usage via "xenstore-control memreport".
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Letting hashtable_remove() return the value of the removed element is
not used anywhere in Xenstore, and it conflicts with a hashtable
created specifying the HASHTABLE_FREE_VALUE flag.
So just drop returning the value.
This of course requires to free the value if the HASHTABLE_FREE_VALUE
was specified, as otherwise it would be a memory leak.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of returning 0 or 1 let chk_domain_generation() return a
boolean value.
Simplify the only caller by removing the ret variable.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
clang 14 is complaining about a NULL dereference for constructs like:
domain_is_unprivileged(conn) ? conn->in : NULL
as it can't know that domain_is_unprivileged(conn) will return false
if conn is NULL.
Fix that by making domain_is_unprivileged() an inline function (and
related to that domid_is_unprivileged(), too).
In order not having to make struct domain public, use conn->id instead
of conn->domain->domid for the test.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
There are some places left where dom0 is associated with domid 0.
Use dom0_domid instead.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Rework the interface and the internals of the per-domain node
accounting:
- rename the functions to domain_nbentry_*() in order to better match
the related counter name
- switch from node pointer to domid as interface, as all nodes have the
owner filled in
- use a common internal function for adding a value to the counter
For the transaction case add a helper function to get the list head
of the per-transaction changed domains, enabling to eliminate the
transaction_entry_*() functions.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Move all code related to struct changed_domain from
xenstored_transaction.c to xenstored_domain.c.
This will be needed later in order to simplify the accounting data
updates in cases of errors during a request.
Split the code to have a more generic base framework.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of storing a pointer to the path which is prepended to
relative paths in struct watch, just use the length of the prepended
path.
It should be noted that the now removed special case of the
relative path being "" in get_watch_path() can't happen at all.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of special casing the permission handling and watch event
firing for the special watch paths "@introduceDomain" and
"@releaseDomain", use static dummy nodes added to the data base when
starting Xenstore.
The node accounting needs to reflect that change by adding the special
nodes in the domain_entry_fix() call in setup_structure().
Note that this requires to rework the calls of fire_watches() for the
special events in order to avoid leaking memory.
Move the check for a valid node name from get_node() to
get_node_canonicalized(), as it allows to use get_node() for the
special nodes, too.
In order to avoid read and write accesses to the special nodes use a
special variant for obtaining the current node data for the permission
handling.
This allows to simplify quite some code. In future sub-nodes of the
special nodes will be possible due to this change, allowing more fine
grained permission control of special events for specific domains.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Move the definition of the log() macro to xenstored_core.h in order
to make it usable from other source files, too.
While at it preserve errno from being modified.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today finding a struct domain by its domain id requires to scan the
list of domains until finding the correct domid.
Add a hashlist for being able to speed this up. This allows to remove
the linking of struct domain in a list. Note that the list of changed
domains per transaction is kept as a list, as there are no known use
cases with more than 4 domains being touched in a single transaction
(this would be a device handled by a driver domain and being assigned
to a HVM domain with device model in a stubdom, plus the control
domain).
Some simple performance tests comparing the scanning and hashlist have
shown that the hashlist will win as soon as more than 6 entries need
to be scanned.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
When a domain has been released by Xen tools, remove all its
registered watches. This avoids sending watch events to the dead domain
when all the nodes related to it are being removed by the Xen tools.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today talloc_free() is not guaranteed to preserve errno, especially in
case a custom destructor is being used.
So preserve errno in talloc_free().
This allows to remove some errno saving outside of talloc.c.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today it is possible to set a flag when calling hashtable_destroy() in
order to specify whether the data associated with the hashtable entries
should be freed or not. The keys of the entries will always be freed.
Change that by replacing the flag of hashtable_destroy() by two flags
for create_hashtable() which will specify whether the data and/or the
key of each entry should be freed or not.
This will enable users to have the key e.g. as part of the data.
Add a new function hashtable_iterate() to call a user specified
function for each entry in the hashtable.
Add new primes to the primetable in order to support smaller sizes of
the hashtable. The primes are selected according to:
https://planetmath.org/goodhashtableprimes
Update the URL in the source as the old one wasn't correct any longer.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Let corrupt() preserve errno in order to be able to simplify error
handling in future.
This is rather easy as the errno value when entering corrupt() is
saved already.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
tdb_logger() is called by TDB for logging errors. As errno is checked
often after doing the logging, tdb_logger() should preserve errno.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today all users of notifier_from_errno() and notifier_to_errno() are
Handling the success case the same way, by using
!rc ? NOTIFY_DONE : notifier_from_errno(rc)
or
(notifier_rc == NOTIFY_DONE) ? 0 : notifier_to_errno(notifier_rc);
Simplify the use cases by moving the handling of the success case into
the functions.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com> # xen/common/sched/
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Instead of directly falling back to the idle unit in case the top
unit from the run queue happened to be not runnable, consult the run
queue again.
Suggested-by: Dario Faggioli <dfaggioli@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
The size of struct active_grant_entry for 64-bit builds is 40 or 48
bytes today (with or without NDEBUG).
It can easily be reduced by 8 bytes by replacing the trans_domain
pointer with the domid of the related domain. trans_domain is only ever
used for transitive grants, which doesn't have any known users.
This reduction will result in less memory usage and (for production
builds) in faster code, as indexing into the active_grant_entry array
will be much easier with an entry having a power-of-2 size.
The performance loss when using transitive grants shouldn't really
matter, given the probability that those aren't in use at all.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add a helper knownalive_domain_from_domid() returning the struct domain
pointer for a domain give by its domid and which is known not being
able to be released (its reference count isn't incremented and no
rcu_lock_domain() is called for it).
In order to simplify coding add an internal helper for doing the lookup
and call that from the new function and similar functions.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add checking of lock recursion to the hypervisor. This is done by using
a percpu data array for storing the address of each taken lock. Any
attempt to take a lock twice (with the exception of recursive
spinlocks) will result in a crash. This is especially meant for
detecting attempts to take a rwlock multiple times as a reader, which
will only result in a deadlock in case of another cpu trying to get the
lock as a writer in between.
The additional checks are not performance neutral, so they are enabled
only in debug builds per default, as the checks are active only with
CONFIG_DEBUG_LOCKS enabled. The size of the percpu data array can be
selected via a boot parameter.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Commit 1283af6465 ("tools/xenstore: remove XEN_LIB_STORED and
XENSTORED_ROOTDIR") removed the systemd file var-lib-xenstored.mount
without removing dependencies to this file.
Fixes: 1283af6465 ("tools/xenstore: remove XEN_LIB_STORED and XENSTORED_ROOTDIR")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Today all timers are migrated to cpu 0 when the system is being
suspended. They are not migrated back after resuming the system again.
This results (at least) to visible problems with the credit scheduler,
as the timer isn't handled on the cpu it was expected to occur, which
will result in an ASSERT() triggering. Other more subtle problems, like
uninterrupted elongated time slices, are probable. The least effect
will be worse performance on cpu 0 resulting from most scheduling
related timer interrupts happening there after suspend/resume.
Add migrating the scheduling related timers of a specific cpu from cpu
0 back to its original cpu when that cpu has gone up when resuming the
system.
Fixes: 0763cd2687 ("xen/sched: don't disable scheduler on cpus during suspend")
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
The code generated for the call_handlers_*() macros needs to avoid
undefined behavior when multiple handlers share the same priority.
The issue is the hypercall number being unverified fed into the macros
and then used to set a mask via "mask = 1ULL << <hypercall-number>".
Avoid a shift amount of more than 63 by setting mask to zero in case
the hypercall number is too large.
Fixes: eca1f00d02 ("xen: generate hypercall interface related code")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
When destroying a domain, any stale permissions of the domain must be
removed from the special nodes "@...", too. This was not done in the
fix for XSA-322.
Fixes: 496306324d ("tools/xenstore: revoke access rights for removed domains")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
XEN_LIB_STORED is serving no real purpose, as it is a mount point for
a tmpfs, so it can be replaced easily by XEN_RUN_STORED.
XENSTORED_ROOTDIR is basically unused already, there is just a single
reference in xs_daemon_rootdir() with a fallback to XEN_LIB_STORED,
and a .gdbinit file setting it.
Remove the .gdbinit file, as it is not known having been used since
ages, and make xs_daemon_rootdir() an alias of xs_daemon_rundir().
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
When finalizing a transaction, any error occurring after checking for
conflicts will result in the transaction being performed only
partially today. Additionally accounting data will not be updated at
the end of the transaction, which might result in further problems
later.
Avoid those problems by multiple modifications:
- free any transaction specific nodes which don't need to be committed
as they haven't been written during the transaction as soon as their
generation count has been verified, this will reduce the risk of
out-of-memory situations
- store the transaction specific node name in struct accessed_node in
order to avoid the need to allocate additional memory for it when
finalizing the transaction
- don't stop the transaction finalization when hitting an error
condition, but try to continue to handle all modified nodes
- in case of a detected error do the accounting update as needed and
call the data base checking only after that
- if writing a node in a transaction is failing (e.g. due to a failed
quota check), fail the transaction, as prior changes to struct
accessed_node can't easily be undone in that case
This is part of XSA-421 / CVE-2022-42326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Tested-by: Julien Grall <jgrall@amazon.com>
In case a node has been created in a transaction and it is later
deleted in the same transaction, the transaction will be terminated
with an error.
As this error is encountered only when handling the deleted node at
transaction finalization, the transaction will have been performed
partially and without updating the accounting information. This will
enable a malicious guest to create arbitrary number of nodes.
This is part of XSA-421 / CVE-2022-42325.
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Julien Grall <jgrall@amazon.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>
Having a file backed data base has the only advantage of being capable
to dump the contents of it while Xenstore is running, and potentially
using less swap space in case the data base can't be kept in memory.
It has the major disadvantage of a huge performance overhead: switching
to keep the data base in memory only speeds up live update of xenstored
with 120000 nodes from 20 minutes to 11 seconds. A complete tree walk
of this configuration will be reduced from 7 seconds to 280 msecs
(measured by "xenstore-control check").
So make the internal memory data base the default and enhance the
"--internal-db" command line parameter to take an optional parameter
allowing to switch the internal data base back to the file based one.
This is part of XSA-419.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In case a domain is removed from Xenstore, remove all nodes owned by
it per default.
This tackles the problem that nodes might be created by a domain
outside its home path in Xenstore, leading to Xenstore hogging more
and more memory. Domain quota don't work in this case if the guest is
rebooting in between.
Since XSA-322 ownership of such stale nodes is transferred to dom0,
which is helping against unintended access, but not against OOM of
Xenstore.
As a fallback for weird cases add a Xenstore start parameter for
keeping today's way to handle stale nodes, adding the risk of Xenstore
hitting an OOM situation.
This is part of XSA-419 / CVE-2022-42322.
Fixes: 496306324d ("tools/xenstore: revoke access rights for removed domains")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of doing an open tree walk using call recursion, use
walk_node_tree() when creating the node records during a live update.
This will reduce code size and avoid many nesting levels of function
calls which could potentially exhaust the stack.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Instead of doing an open tree walk using call recursion, use
walk_node_tree() when deleting a sub-tree of nodes.
This will reduce code size and avoid many nesting levels of function
calls which could potentially exhaust the stack.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Instead of doing an open tree walk using call recursion, use
walk_node_tree() when checking the store for inconsistencies.
This will reduce code size and avoid many nesting levels of function
calls which could potentially exhaust the stack.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
check_store() is using a hash table for storing all node names it has
found via walking the tree. Additionally it using another hash table
for all children of a node to detect duplicate child names.
Simplify that by dropping the second hash table as the first one is
already holding all the needed information.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add a generic function to walk the complete node tree. It will start
at "/" and descend recursively into each child, calling a function
specified by the caller. Depending on the return value of the user
specified function the walk will be aborted, continued, or the current
child will be skipped by not descending into its children.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
In case of write_node() returning an error, remove_child_entry() will
call corrupt() today. This could result in an endless recursion, as
remove_child_entry() is called by corrupt(), too:
corrupt()
check_store()
check_store_()
remove_child_entry()
Fix that by letting remove_child_entry() return an error instead and
let the caller decide what to do.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In order to reduce stack usage due to recursion, switch
construct_node() to use a loop instead.
This is part of XSA-418 / CVE-2022-42321.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today chk_domain_generation() is being used to check whether a node
permission entry is still valid or whether it is referring to a domain
no longer existing. This is done by comparing the node's and the
domain's generation count.
In case no struct domain is existing for a checked domain, but the
domain itself is valid, chk_domain_generation() assumes it is being
called due to the first node created for a new domain and it will
return success.
This might be wrong in case the checked permission is related to an
old domain, which has just been replaced with a new domain using the
same domid.
Fix that by letting chk_domain_generation() fail in case a struct
domain isn't found. In order to cover the case of the first node for
a new domain try to allocate the needed struct domain explicitly when
processing the related SET_PERMS command. In case a referenced domain
isn't existing, flag the related permission to be ignored right away.
This is XSA-417 / CVE-2022-42320.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Using the struct buffered data pointer of the current processed request
for temporary data allocations has a major drawback: the used area (and
with that the temporary data) is freed only after the response of the
request has been written to the ring page or has been read via the
socket. This can happen much later in case a guest isn't reading its
responses fast enough.
As the temporary data can be safely freed after creating the response,
add a temporary context for that purpose and use that for allocating
the temporary memory, as it was already the case before commit
cc06124648 ("xenstore: add small default data buffer to internal
struct").
Some sub-functions need to gain the "const" attribute for the talloc
context.
This is XSA-416 / CVE-2022-42319.
Fixes: cc06124648 ("xenstore: add small default data buffer to internal struct")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add a support statement for the scope of support regarding different
Xenstore variants. Especially oxenstored does not (yet) have security
support of untrusted driver domains, as those might drive oxenstored
out of memory by creating lots of watch events for the guests they are
servicing.
Add a statement regarding Live Update support of oxenstored.
This is part of XSA-326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Christian Lindig <christian.lindig@citrix.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>
Some quota variables are not exported via header files.
This is part of XSA-326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Add the memory accounting for Xenstore nodes. In order to make this
not too complicated allow for some sloppiness when writing nodes. Any
hard quota violation will result in no further requests to be accepted.
This is part of XSA-326 / CVE-2022-42315.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add the memory accounting for registered watches.
When a socket connection is destroyed, the associated watches are
removed, too. In order to keep memory accounting correct the watches
must be removed explicitly via a call of conn_delete_all_watches() from
destroy_conn().
This is part of XSA-326 / CVE-2022-42315.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add the memory accounting for queued responses.
In case adding a watch event for a guest is causing the hard memory
quota of that guest to be violated, the event is dropped. This will
ensure that it is impossible to drive another guest past its memory
quota by generating insane amounts of events for that guest. This is
especially important for protecting driver domains from that attack
vector.
This is part of XSA-326 / CVE-2022-42315.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The amount of memory a domain can consume in Xenstore is limited by
various quota today, but even with sane quota a domain can still
consume rather large memory quantities.
Add the infrastructure for keeping track of the amount of memory a
domain is consuming in Xenstore. Note that this is only the memory a
domain has direct control over, so any internal administration data
needed by Xenstore only is not being accounted for.
There are two quotas defined: a soft quota which will result in a
warning issued via syslog() when it is exceeded, and a hard quota
resulting in a stop of accepting further requests or watch events as
long as the hard quota would be violated by accepting those.
Setting any of those quotas to 0 will disable it.
As default values use 2MB per domain for the soft limit (this basically
covers the allowed case to create 1000 nodes needing 2kB each), and
2.5MB for the hard limit.
This is part of XSA-326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Setting up the basic structure when introducing dom0 has the advantage
to be able to add proper node memory accounting for the added nodes
later.
This makes it possible to do proper node accounting, too.
An additional requirement to make that work fine is to correct the
owner of the created nodes to be dom0_domid instead of domid 0.
This is part of XSA-326.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Juergen Gross