Commit Graph
15375 Commits
Author SHA1 Message Date
Juergen Gross dcba0801cb tools/xenstore: fix XSA-417 patch
The fix for XSA-417 had a bug: domain_alloc_permrefs() will not return
a negative value in case of an error, but a plain errno value.

Note this is not considered to be a security issue, as the only case
where domain_alloc_permrefs() will return an error is a failed memory
allocation. As a guest should not be able to drive Xenstore out of
memory, this is NOT a problem a guest can trigger at will.

Fixes: ab12821822 ("tools/xenstore: fix checking node permissions")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
master commit: 0c53c638e1
master date: 2023-07-21 08:32:43 +0200
2023-08-03 16:33:43 +02:00
Andrew Cooper f5b0de706b tools: Remove the use of K&R functions
Clang-15 (as seen in the FreeBSD 14 tests) complains:

  xg_main.c:1248 error: a function declaration without a
  prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
  xg_init()
         ^
          void

The error message is a bit confusing but appears to new as part of
-Wdeprecated-non-prototype which is part of supporting C2x which formally
removes K&R syntax.

Either way, fix the identified function.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
master commit: e2312e41f0
master date: 2023-02-17 11:01:54 +0000
2023-07-18 10:25:20 +02:00
Olaf Hering c9c8b20ebc tools: convert bitfields to unsigned type
clang complains about the signed type:

implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Wsingle-bit-bitfield-constant-conversion]

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

Backport: Dropped the libxenvchan change, for the original commit saying

"The potential ABI change in libxenvchan is covered by the Xen version
 based SONAME."

which won't hold on stable trees.
master commit: 99ab02f63e
master date: 2023-05-16 20:03:02 +0100
2023-07-17 08:32:19 +02:00
Olaf Hering de80f09e7d tools/libs/guest: assist gcc13's realloc analyzer
gcc13 fails to track the allocated memory in backup_ptes:

xg_offline_page.c: In function 'backup_ptes':
xg_offline_page.c:191:13: error: pointer 'orig' may be used after 'realloc' [-Werror=use-after-free]
  191 |             free(orig);

Assist the analyzer by slightly rearranging the code:
In case realloc succeeds, the previous allocation is either extended
or released internally. In case realloc fails, the previous allocation
is left unchanged. Return an error in this case, the caller will
release the currently allocated memory in its error path.

http://bugzilla.suse.com/show_bug.cgi?id=1210570

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Compile-tested-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: 99a9c3d714
master date: 2023-05-03 15:06:41 +0200
2023-05-23 15:01:53 +02:00
Juergen Gross 1df1a2acab tools/xenstore: fix quota check in transaction_fix_domains()
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>
master commit: f6b801c36b
master date: 2023-03-29 22:02:36 +0100
2023-04-24 13:03:36 +02:00
David Woodhouse 54102e428b libacpi: fix PCI hotplug AML
The emulated PIIX3 uses a nybble for the status of each PCI function,
so the status for e.g. slot 0 functions 0 and 1 respectively can be
read as (\_GPE.PH00 & 0x0F), and (\_GPE.PH00 >> 0x04).

The AML that Xen gives to a guest gets the operand order for the odd-
numbered functions the wrong way round, returning (0x04 >> \_GPE.PH00)
instead.

As far as I can tell, this was the wrong way round in Xen from the
moment that PCI hotplug was first introduced in commit 83d82e6f35:

+                    ShiftRight (0x4, \_GPE.PH00, Local1)
+                    Return (Local1) /* IN status as the _STA */

Or maybe there's bizarre AML operand ordering going on there, like
Intel's wrong-way-round assembler, and it only broke later when it was
changed to being generated?

Either way, it's definitely wrong now, and instrumenting a Linux guest
shows that it correctly sees _STA being 0x00 in function 0 of an empty
slot, but then the loop in acpiphp_glue.c::get_slot_status() goes on to
look at function 1 and sees that _STA evaluates to 0x04. Thus reporting
an adapter is present in every slot in /sys/bus/pci/slots/*

Quite why Linux wants to look for function 1 being physically present
when function 0 isn't... I don't want to think about right now.

Fixes: 83d82e6f35 ("hvmloader: pass-through: multi-function PCI hot-plug")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: b190af7d3e
master date: 2023-03-20 17:12:34 +0100
2023-03-21 13:53:25 +01:00
Bernhard Kaindl 5ce8d2aef8 tools/xenmon: Fix xenmon.py for with python3.x
Fixes for Py3:
* class Delayed(): file not defined; also an error for pylint -E.  Inherit
  object instead for Py2 compatibility.  Fix DomainInfo() too.
* Inconsistent use of tabs and spaces for indentation (in one block)

Signed-off-by: Bernhard Kaindl <bernhard.kaindl@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 3a59443c1d
master date: 2023-02-06 10:22:12 +0000
2023-03-21 13:49:47 +01:00
Marek Marczykowski-Górecki 0cbffc6099 tools/python: change 's#' size type for Python >= 3.10
Python < 3.10 by default uses 'int' type for data+size string types
(s#), unless PY_SSIZE_T_CLEAN is defined - in which case it uses
Py_ssize_t. The former behavior was removed in Python 3.10 and now it's
required to define PY_SSIZE_T_CLEAN before including Python.h, and using
Py_ssize_t for the length argument. The PY_SSIZE_T_CLEAN behavior is
supported since Python 2.5.

Adjust bindings accordingly.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
master commit: 897257ba49
master date: 2023-02-06 08:50:13 +0100
2023-03-21 13:49:28 +01:00
Edwin Török 25d103f2eb libs/guest: Fix leak on realloc failure in backup_ptes()
From `man 2 realloc`:

  If realloc() fails, the original block is left untouched; it is not freed or moved.

Found using GCC -fanalyzer:

  |  184 |         backup->entries = realloc(backup->entries,
  |      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  |      |         |               | |
  |      |         |               | (91) when ‘realloc’ fails
  |      |         |               (92) ‘old_ptes.entries’ leaks here; was allocated at (44)
  |      |         (90) ...to here

Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 275d13184c
master date: 2023-02-27 15:51:23 +0000
2023-03-03 08:17:23 +01:00
Andrew Cooper b181a3a553 libs/guest: Fix resource leaks in xc_core_arch_map_p2m_tree_rw()
Edwin, with the help of GCC's -fanalyzer, identified that p2m_frame_list_list
gets leaked.  What fanalyzer can't see is that the live_p2m_frame_list_list
and live_p2m_frame_list foreign mappings are leaked too.

Rework the logic so the out path is executed unconditionally, which cleans up
all the intermediate allocations/mappings appropriately.

Fixes: bd7a29c3d0 ("tools/libs/ctrl: fix xc_core_arch_map_p2m() to support linear p2m table")
Reported-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
master commit: 1868d7f226
master date: 2023-02-27 15:51:23 +0000
2023-03-03 08:17:04 +01:00
Bertrand Marquis a2adc7fcc2 tools: Use PKG_CONFIG_FILE instead of PKG_CONFIG variable
Replace PKG_CONFIG variable name with PKG_CONFIG_FILE for the name of
the pkg-config file.
This is preventing a conflict in some build systems where PKG_CONFIG
actually contains the path to the pkg-config executable to use, as the
default assignment in libs.mk is using a weak assignment (?=).

This problem has been found when trying to build the latest version of
Xen tools using buildroot.

Fixes: d400dc5729 ("tools: tweak tools/libs/libs.mk for being able to support libxenctrl")
Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
master commit: b97e2fe7b9
master date: 2023-02-24 17:44:29 +0000
2023-03-03 08:16:45 +01:00
Andrew Cooper 5857cc632b x86/shskt: Disable CET-SS on parts susceptible to fractured updates
Refer to Intel SDM Rev 70 (Dec 2022), Vol3 17.2.3 "Supervisor Shadow Stack
Token".

Architecturally, an event delivery which starts in CPL<3 and switches shadow
stack will first validate the Supervisor Shadow Stack Token (setting the busy
bit), then pushes CS/LIP/SSP.  One example of this is an NMI interrupting Xen.

Some CPUs suffer from an issue called fracturing, whereby a fault/vmexit/etc
between setting the busy bit and completing the event injection renders the
action non-restartable, because when it comes time to restart, the busy bit is
found to be already set.

This is far more easily encountered under virt, yet it is not the fault of the
hypervisor, nor the fault of the guest kernel.  The fault lies somewhere
between the architectural specification, and the uarch behaviour.

Intel have allocated CPUID.7[1].ecx[18] CET_SSS to enumerate that supervisor
shadow stacks are safe to use.  Because of how Xen lays out its shadow stacks,
fracturing is not expected to be a problem on native.

Detect this case on boot and default to not using shstk if virtualised.
Specifying `cet=shstk` on the command line will override this heuristic and
enable shadow stacks irrespective.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 01e7477d1b
master date: 2023-02-09 18:26:17 +0000
2023-03-03 08:12:24 +01:00
Andrew Cooper 2094f834b8 x86/cpuid: Infrastructure for leaves 7:1{ecx,edx}
We don't actually need ecx yet, but adding it in now will reduce the amount to
which leaf 7 is out of order in a featureset.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: b4a23bf629
master date: 2023-02-09 18:26:17 +0000
2023-03-03 08:06:44 +01:00
Anthony PERARD e4b5dff3d0 libs/util: Fix parallel build between flex/bison and CC rules
flex/bison generate two targets, and when those targets are
prerequisite of other rules they are considered independently by make.

We can have a situation where the .c file is out-of-date but not the
.h, git checkout for example. In this case, if a rule only have the .h
file as prerequiste, make will procced and start to build the object.
In parallel, another target can have the .c file as prerequisite and
make will find out it need re-generating and do so, changing the .h at
the same time. This parallel task breaks the first one.

To avoid this scenario, we put both the header and the source as
prerequisite for all object even if they only need the header.

Reported-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: bf652a50fb
master date: 2023-02-09 18:26:17 +0000
2023-03-03 08:06:23 +01:00
Andrew Cooper 1b6acdeeb2 tools/ocaml/libs: Fix memory/resource leaks with caml_alloc_custom()
All caml_alloc_*() functions can throw exceptions, and longjump out of
context.  If this happens, we leak the xch/xce handle.

Reorder the logic to allocate the the Ocaml object first.

Fixes: 8b3c06a3e5 ("tools/ocaml/xenctrl: OCaml 5 support, fix use-after-free")
Fixes: 22d5affdf0 ("tools/ocaml/evtchn: OCaml 5 support, fix potential resource leak")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit d69ccf52ad)
2023-02-09 15:58:51 +00:00
Andrew Cooper 1fdff77e26 tools/ocaml/xc: Don't reference Abstract_Tag objects with the GC lock released
The intf->{addr,len} references in the xc_map_foreign_range() call are unsafe.
From the manual:

  https://ocaml.org/manual/intfc.html#ss:parallel-execution-long-running-c-code

"After caml_release_runtime_system() was called and until
caml_acquire_runtime_system() is called, the C code must not access any OCaml
data, nor call any function of the run-time system, nor call back into OCaml
code."

More than what the manual says, the intf pointer is (potentially) invalidated
by caml_enter_blocking_section() if another thread happens to perform garbage
collection at just the right (wrong) moment.

Rewrite the logic.  There's no need to stash data in the Ocaml object until
the success path at the very end.

Fixes: 8b7ce06a2d ("ocaml: Add XC bindings.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 9e7c74e6f9)
2023-02-09 15:58:51 +00:00
Edwin Török 854013084e tools/ocaml/xc: Fix binding for xc_domain_assign_device()
The patch adding this binding was plain broken, and unreviewed.  It modified
the C stub to add a 4th parameter without an equivalent adjustment in the
Ocaml side of the bindings.

In 64bit builds, this causes us to dereference whatever dead value is in %rcx
when trying to interpret the rflags parameter.

This has gone unnoticed because Xapi doesn't use this binding (it has its
own), but unbreak the binding by passing RDM_RELAXED unconditionally for
now (matching the libxl default behaviour).

Fixes: 9b34056cb4 ("tools: extend xc_assign_device() to support rdm reservation policy")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 4250683842)
2023-02-09 15:58:51 +00:00
Edwin Török e18faeb91e tools/ocaml/evtchn: Don't reference Custom objects with the GC lock released
The modification to the _H() macro for Ocaml 5 support introduced a subtle
bug.  From the manual:

  https://ocaml.org/manual/intfc.html#ss:parallel-execution-long-running-c-code

"After caml_release_runtime_system() was called and until
caml_acquire_runtime_system() is called, the C code must not access any OCaml
data, nor call any function of the run-time system, nor call back into OCaml
code."

Previously, the value was a naked C pointer, so dereferencing it wasn't
"accessing any Ocaml data", but the fix to avoid naked C pointers added a
layer of indirection through an Ocaml Custom object, meaning that the common
pattern of using _H() in a blocking section is unsafe.

In order to fix:

 * Drop the _H() macro and replace it with a static inline xce_of_val().
 * Opencode the assignment into Data_custom_val() in the two constructors.
 * Rename "value xce" parameters to "value xce_val" so we can consistently
   have "xenevtchn_handle *xce" on the stack, and obtain the pointer with the
   GC lock still held.

Fixes: 22d5affdf0 ("tools/ocaml/evtchn: OCaml 5 support, fix potential resource leak")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 2636d8ff7a)
2023-02-09 15:58:51 +00:00
Andrew Cooper 6d66fb984c tools/ocaml/libs: Allocate the correct amount of memory for Abstract_tag
caml_alloc() takes units of Wsize (word size), not bytes.  As a consequence,
we're allocating 4 or 8 times too much memory.

Ocaml has a helper, Wsize_bsize(), but it truncates cases which aren't an
exact multiple.  Use a BUILD_BUG_ON() to cover the potential for truncation,
as there's no rounding-up form of the helper.

Fixes: 8b7ce06a2d ("ocaml: Add XC bindings.")
Fixes: d3e649277a ("ocaml: add mmap bindings implementation.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 36eb2de31b)
2023-02-09 15:58:51 +00:00
Edwin Török 552e5f28d4 tools/ocaml/libs: Don't declare stubs as taking void
There is no such thing as an Ocaml function (C stub or otherwise) taking no
parameters.  In the absence of any other parameters, unit is still passed.

This doesn't explode with any ABI we care about, but would malfunction for an
ABI environment such as stdcall.

Fixes: c3afd398ba ("ocaml: Add XS bindings.")
Fixes: 8b7ce06a2d ("ocaml: Add XC bindings.")
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit ff8b560be8)
2023-02-09 15:58:51 +00:00
Edwin Török fd1c70442d tools/oxenstored: validate config file before live update
The configuration file can contain typos or various errors that could prevent
live update from succeeding (e.g. a flag only valid on a different version).
Unknown entries in the config file would be ignored on startup normally,
add a strict --config-test that live-update can use to check that the config file
is valid *for the new binary*.

For compatibility with running old code during live update recognize
--live --help as an equivalent to --config-test.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit e6f07052ce)
2023-02-09 15:58:51 +00:00
Edwin Török f7c4fab9b5 tools/ocaml/xb: Drop Xs_ring.write
This function is unusued (only Xs_ring.write_substring is used), and the
bytes/string conversion here is backwards: the C stub implements the bytes
version and then we use a Bytes.unsafe_of_string to convert a string into
bytes.

However the operation here really is read-only: we read from the string and
write it to the ring, so the C stub should implement the read-only string
version, and if needed we could use Bytes.unsafe_to_string to be able to send
'bytes'. However that is not necessary as the 'bytes' version is dropped above.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 01f139215e)
2023-02-09 15:58:51 +00:00
Edwin Török 049d16c8ce tools/ocaml/xb,mmap: Use Data_abstract_val wrapper
This is not strictly necessary since it is essentially a no-op currently: a
cast to void * and value *, even in OCaml 5.0.

However it does make it clearer that what we have here is not a regular OCaml
value, but one allocated with Abstract_tag or Custom_tag, and follows the
example from the manual more closely:
https://v2.ocaml.org/manual/intfc.html#ss:c-outside-head

It also makes it clearer that these modules have been reviewed for
compat with OCaml 5.0.

We cannot use OCaml finalizers here, because we want exact control over when
to unmap these pages from remote domains.

No functional change.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit d2ccc63711)
2023-02-09 15:58:51 +00:00
Edwin Török 8c66a2d88a tools/ocaml/xenctrl: Use larger chunksize in domain_getinfolist
domain_getinfolist() is quadratic with the number of domains, because of the
behaviour of the underlying hypercall.  Nevertheless, getting domain info in
blocks of 1024 is far more efficient than blocks of 2.

In a scalability testing scenario with ~1000 VMs, a combination of this and
the previous change takes xenopsd's wallclock time in domain_getinfolist()
down from 88% to 0.02%

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Tested-by: Pau Ruiz Safont <pau.safont@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 95db09b1b1)
2023-02-09 15:58:51 +00:00
Edwin Török c6a3d14df0 tools/ocaml/xenctrl: Make domain_getinfolist tail recursive
domain_getinfolist() is quadratic with the number of domains, because of the
behaviour of the underlying hypercall.  xenopsd was further observed to be
wasting excessive quantites of time manipulating the list of already-obtained
domains.

Implement a tail recursive `rev_concat` equivalent to `concat |> rev`, and use
it instead of calling `@` multiple times.

An incidental benefit is that the list of domains will now be in domid order,
instead of having pairs of 2 domains changing direction every time.

In a scalability testing scenario with ~1000 VMs, a combination of this and
the subsequent change takes xenopsd's wallclock time in domain_getinfolist()
down from 88% to 0.02%

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Tested-by: Pau Ruiz Safont <pau.safont@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit c3b6be714c)
2023-02-09 15:58:51 +00:00
Jason Andryuk 6e081438bf libxl: fix guest kexec - skip cpuid policy
When a domain performs a kexec (soft reset), libxl__build_pre() is
called with the existing domid.  Calling libxl__cpuid_legacy() on the
existing domain fails since the cpuid policy has already been set, and
the guest isn't rebuilt and doesn't kexec.

xc: error: Failed to set d1's policy (err leaf 0xffffffff, subleaf 0xffffffff, msr 0xffffffff) (17 = File exists): Internal error
libxl: error: libxl_cpuid.c:494:libxl__cpuid_legacy: Domain 1:Failed to apply CPUID policy: File exists
libxl: error: libxl_create.c:1641:domcreate_rebuild_done: Domain 1:cannot (re-)build domain: -3
libxl: error: libxl_xshelp.c:201:libxl__xs_read_mandatory: xenstore read failed: `/libxl/1/type': No such file or directory
libxl: warning: libxl_dom.c:49:libxl__domain_type: unable to get domain type for domid=1, assuming HVM

During a soft_reset, skip calling libxl__cpuid_legacy() to avoid the
issue.  Before commit 34990446ca, the libxl__cpuid_legacy() failure
would have been ignored, so kexec would continue.

Fixes: 34990446ca ("libxl: don't ignore the return value from xc_cpuid_apply_policy")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
master commit: 1e454c2b5b
master date: 2023-01-26 10:58:23 +0100
2023-02-07 17:06:47 +01:00
Anthony PERARD 998c03b2ab tools: Fix build with recent QEMU, use "--enable-trace-backends"
The configure option "--enable-trace-backend" isn't accepted anymore
and we should use "--enable-trace-backends" instead which was
introduce in 2014 and allow multiple backends.

"--enable-trace-backends" was introduced by:
    5b808275f3bb ("trace: Multi-backend tracing")
The backward compatible option "--enable-trace-backend" is removed by
    10229ec3b0ff ("configure: remove backwards-compatibility and obsolete options")

As we already use ./configure options that wouldn't be accepted by
older version of QEMU's configure, we will simply use the new spelling
for the option and avoid trying to detect which spelling to use.

We already make use if "--firmwarepath=" which was introduced by
    3d5eecab4a5a ("Add --firmwarepath to configure")
which already include the new spelling for "--enable-trace-backends".

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
master commit: e66d450b6e
master date: 2023-01-11 10:45:29 +0100
2023-02-07 17:03:51 +01:00
Andrew Cooper 03a43f548e tools/oxenstored: Render backtraces more nicely in Syslog
fallback_exception_handler feeds a string with embedded newlines directly into
syslog().  While this is an improvement on getting nothing, syslogd escapes
all control characters it gets, and emits one (long) log line.

Fix the problem generally in the syslog stub.  As we already have a local copy
of the string, split it in place and emit one syslog() call per line.

Also tweak Logging.msg_of to avoid putting an extra newline on a string which
already ends with one.

Fixes: ee7815f49f ("tools/oxenstored: Set uncaught exception handler")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit d2162d884c)
2022-12-12 11:04:12 +00:00
Edwin Török 4a8ff8bf1b tools/oxenstored/syslog: Avoid potential NULL dereference
strdup() may return NULL.  Check for this before passing to syslog().

Drop const from c_msg.  It is bogus, as demonstrated by the need to cast to
void * in order to free the memory.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit acd3fb6d65)
2022-12-12 11:04:12 +00:00
Edwin Török a41d969353 tools/oxenstored: Set uncaught exception handler
Unhandled exceptions go to stderr by default, but this doesn't typically work
for oxenstored because:
 * daemonize reopens stderr as /dev/null
 * systemd redirects stderr to /dev/null too

Debugging an unhandled exception requires reproducing the issue locally when
using --no-fork, and is not conducive to figuring out what went wrong on a
remote system.

Install a custom handler which also tries to render the backtrace to the
configured syslog facility, and DAEMON|ERR otherwise.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit ee7815f49f)
2022-12-12 11:04:12 +00:00
Edwin Török 724d003ecc tools/oxenstored: Log live update issues at warning level
During live update, oxenstored tries a best effort approach to recover as many
domains and information as possible even if it encounters errors restoring
some domains.

However, logging about misunderstood input is more severe than simply info.
Log it at warning instead.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 3f02e0a70f)
2022-12-12 11:04:12 +00:00
Edwin Török 8108d3c99c tools/oxenstored: Keep /dev/xen/evtchn open across live update
Closing the evtchn handle will unbind and free all local ports.  The new
xenstored would need to rebind all evtchns, which is work that we don't want
or need to be doing during the critical handover period.

However, it turns out that the Windows PV drivers also rebind their local port
too across suspend/resume, leaving (o)xenstored with a stale idea of the
remote port to use.  In this case, reusing the established connection is the
only robust option.

Therefore:
 * Have oxenstored open /dev/xen/evtchn without CLOEXEC at start of day.
 * Extend the handover information with the evtchn fd, domexc virq local port,
   and the local port number for each domain connection.
 * Have (the new) oxenstored recover the open handle using Xeneventchn.fdopen,
   and use the provided local ports rather than trying to rebind them.

When this new information isn't present (i.e. live updating from an oxenstored
prior to this change), the best-effort status quo will have to do.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 9b224c2529)
2022-12-12 11:04:12 +00:00
Andrew Cooper e5502f2bbd tools/oxenstored: Rework Domain evtchn handling to use port_pair
Inter-domain event channels are always a pair of local and remote ports.
Right now the handling is asymmetric, caused by the fact that the evtchn is
bound after the associated Domain object is constructed.

First, move binding of the event channel into the Domain.make() constructor.
This means the local port no longer needs to be an option.  It also removes
the final callers of Domain.bind_interdomain.

Next, introduce a new port_pair type to encapsulate the fact that these two
should be updated together, and replace the previous port and remote_port
fields.  This refactoring also changes the Domain.get_port interface (removing
an option) so take the opportunity to name it get_local_port instead.

Also, this fixes a use-after-free risk with Domain.close.  Once the evtchn has
been unbound, the same local port number can be reused for a different
purpose, so explicitly invalidate the ports to prevent their accidental misuse
in the future.

This also cleans up some of the debugging, to always print a port pair.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit df2db174b3)
2022-12-12 11:04:12 +00:00
Andrew Cooper 5c11a898e5 tools/oxenstored: Implement Domain.rebind_evtchn
Generally speaking, the event channel local/remote port is fixed for the
lifetime of the associated domain object.  The exception to this is a
secondary XS_INTRODUCE (defined to re-bind to a new event channel) which pokes
around at the domain object's internal state.

We need to refactor the evtchn handling to support live update, so start by
moving the relevant manipulation into Domain.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit aecdc28d95)
2022-12-12 11:04:12 +00:00
Andrew Cooper 0ce5f6ddf9 tools/oxenstored: Rename some 'port' variables to 'remote_port'
This will make the logic clearer when we plumb local_port through these
functions.

While doing this, rearrange the construct in Domains.create0 to separate the
remote port handling from the interface handling.  (The interface logic is
dubious in several ways, but not altered by this cleanup.)

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 31fbee749a)
2022-12-12 11:04:12 +00:00
Andrew Cooper cd69a4cf61 tools/oxenstored: Bind the DOM_EXC VIRQ in in Event.init()
Xenstored always needs to bind the DOM_EXC VIRQ.

Instead of doing it shortly after the call to Event.init(), do it in the
constructor directly.  This removes the need for the field to be a mutable
option.

It will also simplify a future change to support live update.  Rename the
field from virq_port (which could be any VIRQ) to it's proper name.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 9804a5db43)
2022-12-12 11:04:12 +00:00
Andrew Cooper bb3dcf7bc8 tools/oxenstored: Style fixes to Domain
This file has some style problems so severe that they interfere with the
readability of the subsequent bugfix patches.

Fix these issues ahead of time, to make the subsequent changes more readable.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit b45bfaf359)
2022-12-12 11:04:12 +00:00
Edwin Török c96f51bc3e tools/ocaml/evtchn: Extend the init() binding with a cloexec flag
For live update, oxenstored wants to clear CLOEXEC on the evtchn handle, so it
survives the execve() into the new oxenstored.

Have the new interface match how cloexec works in other Ocaml standard
libraries.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 9bafe4a533)
2022-12-12 11:04:12 +00:00
Edwin Török dd3006b1dd tools/ocaml/evtchn: Add binding for xenevtchn_fdopen()
For live update, the new oxenstored needs to reconstruct an evtchn object
around an existing file descriptor.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 7ba68a6c55)
2022-12-12 11:04:12 +00:00
Edwin Török 5e41efcc50 tools/ocaml/evtchn: OCaml 5 support, fix potential resource leak
There is no binding for xenevtchn_close().  In principle, this is a resource
leak, but the typical usage is as a singleton that lives for the lifetime of
the program.

Ocaml 5 no longer permits storing a naked C pointer in an Ocaml value.

Therefore, use a Custom block.  This allows us to use the finaliser callback
to call xenevtchn_close(), if the Ocaml object goes out of scope.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit 22d5affdf0)
2022-12-12 11:04:12 +00:00
Andrew Cooper 94fbce235e tools/oxenstored: Fix incorrect scope after an if statement
A debug statement got inserted into a single-expression if statement.

Insert brackets to give the intended meaning, rather than the actual meaning
where the "let con = Connections..." is outside and executed unconditionally.

This results in some unnecessary ring checks for domains which otherwise have
IO credit.

Fixes: 42f0581a91 ("tools/oxenstored: Implement live update for socket connections")
Reported-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit ee36179371)
2022-12-12 11:04:12 +00:00
Edwin Török 3774760ae0 tools/ocaml/xenstored/store.ml: fix build error
Building with Dune in release mode fails with:
```
File "ocaml/xenstored/store.ml", line 464, characters 13-32:
Warning 18: this type-based record disambiguation is not principal.
File "ocaml/xenstored/store.ml", line 1:
Error: Some fatal warnings were triggered (1 occurrences)
```

This is a warning to help keep the code futureproof, quoting from its
documentation:
> Check information path during type-checking, to make sure that all types are
> derived in a principal way. When using labelled arguments and/or polymorphic
> methods, this flag is required to ensure future versions of the compiler will
> be able to infer types correctly, even if internal algorithms change. All
> programs accepted in -principal mode are also accepted in the default mode with
> equivalent types, but different binary signatures, and this may slow down type
> checking; yet it is a good idea to use it once before publishing source code.

Fixes: db471408ed "tools/ocaml/xenstored: Fix quota bypass on domain shutdown"

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
(cherry picked from commit 124492eff8)
2022-12-12 11:04:12 +00:00
Edwin Török 8837acbcda tools/ocaml/xenstored: fix live update exception
During live update we will load the /tool/xenstored path from the previous binary,
and then try to mkdir /tool again which will fail with EEXIST.
Check for existence of the path before creating it.

The write call to /tool/xenstored should not need any changes
(and we do want to overwrite any previous path, in case it changed).

Prior to 7110192b1d live update would work only if the binary path was
specified, and with 7110192b1d and this live update also works when
no binary path is specified in `xenstore-control live-update`.

Fixes: 7110192b1d ("tools/oxenstored: Fix Oxenstored Live Update")
Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
(cherry picked from commit f838b95677)
2022-12-12 11:04:12 +00:00
Andrew Cooper dae2ebabf8 tools/oxenstored: Fix Oxenstored Live Update
tl;dr This hunk was part of the patch emailed to xen-devel, but was missing
from what ultimately got committed.

https://lore.kernel.org/xen-devel/4164cb728313c3b9fc38cf5e9ecb790ac93a9600.1610748224.git.edvin.torok@citrix.com/
is the patch in question, but was part of a series that had threading issues.
I have a vague recollection that I sourced the commits from a local branch,
which clearly wasn't as up-to-date as I had thought.

Either way, it's my fault/mistake, and this hunk should have been part of what
got comitted.

Fixes: 00c48f57ab ("tools/oxenstored: Start live update process")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
(cherry picked from commit 7110192b1d)
2022-12-12 11:04:12 +00:00
Anthony PERARD 4320b31106 libs/light: Propagate libxl__arch_domain_create() return code
Commit 34990446ca started to overwrite the `rc` value from
libxl__arch_domain_create(), thus error aren't propagated anymore.

Check `rc` value before doing the next thing.

Fixes: 34990446ca ("libxl: don't ignore the return value from xc_cpuid_apply_policy")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
master commit: 8cdfbf95b1
master date: 2022-11-21 12:23:01 +0100
2022-11-28 11:46:53 +01:00
Juergen Gross a524495aac tools/xenstore: call remove_domid_from_perm() for special nodes
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>
master commit: 0751a75e39
master date: 2022-11-02 12:08:22 +0100
2022-11-09 10:59:42 +01:00
Andrew Cooper b1a1df345a x86/spec-ctrl: Enumeration for IBPB_RET
The IBPB_RET bit indicates that the CPU's implementation of MSR_PRED_CMD.IBPB
does flush the RSB/RAS too.

This is part of XSA-422 / CVE-2022-23824.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
(cherry picked from commit 24496558e6)
2022-11-04 13:20:27 +00:00
Juergen Gross 1bdd7c438b tools/xenstore: harden transaction finalization against errors
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>
(cherry picked from commit 2dd823ca72)
2022-11-01 14:07:24 +00:00
Juergen Gross 4305807dfd tools/xenstore: fix deleting node in transaction
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>
(cherry picked from commit 13ac37f141)
2022-11-01 14:07:24 +00:00
Edwin Török 635390415f tools/ocaml: Ensure packet size is never negative
Integers in Ocaml have 63 or 31 bits of signed precision.

On 64-bit builds of Ocaml, this is fine because a C uint32_t always fits
within a 63-bit signed integer.

In 32-bit builds of Ocaml, this goes wrong.  The C uint32_t is truncated
first (loses the top bit), then has a unsigned/signed mismatch.

A "negative" value (i.e. a packet on the ring of between 1G and 2G in size)
will trigger an exception later in Bytes.make in xb.ml, and because the packet
is not removed from the ring, the exception re-triggers on every subsequent
query, creating a livelock.

Fix both the source of the exception in Xb, and as defence in depth, mark the
domain as bad for any Invalid_argument exceptions to avoid the risk of
livelock.

This is XSA-420 / CVE-2022-42324.

Signed-off-by: Edwin Török <edvin.torok@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
(cherry picked from commit ae34df4d82)
2022-11-01 14:07:24 +00:00