The file exclude-list.json contains files that are classified as
adopted code for MISRA compliance. Therefore, this file is used to
automatically generate a suitable .ecl configuration for ECLAIR.
As such, many entries in out_of_scope.ecl can be removed, as they
would be duplicates.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add the rules accepted in the last three MISRA C working group meetings.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The xen sources contain violations of MISRA C:2012 Rule 14.4 whose
headline states:
"The controlling expression of an if statement and the controlling
expression of an iteration-statement shall have essentially Boolean type".
Struct domain member is_dying is an anonymous enum designed to act as boolean.
Add deviation to mark its uses in controlling expressions as deliberate.
Signed-off-by: Maria Celeste Cesario <maria.celeste.cesario@bugseng.com>
Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Update ECLAIR configuration to take into account the adopted files
and type "ret_t".
Update docs/misra/deviations.rst accordingly.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
The labels marked with __maybe_unused are either used only
in certain build configurations or deliberately unused.
See the justification in docs/misra/deviations.rst.
No functional changes.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
x86/efi/check.c is not part of the final Xen binary, therefore
it doesn't need to conform to MISRA guidelines at the moment.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The differences between inline, __inline and __inline__ keywords (as far as
GCC is concenred at least) are a vestigial remnant of older C standards, and
in Xen we use inline almost exclusively.
Replace __inline and __inline__ with regular inline, and remove their
exceptions from the MISRA configuration.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
As stated in rules.rst, functions used only in asm modules
are allowed to have no prior declaration visible when being
defined, hence these functions are marked with an
'asmlinkage' macro, which is then deviated for MISRA C:2012
Rule 8.4.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
[stefano: improve deviation text]
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
These files should not conform to MISRA guidelines at the moment,
therefore they are added to the exclusion list.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Update ECLAIR configuration to take into account the search
procedure adopted by Unix linkers.
Update deviations.rst accordingly and tag Rule 8.6 as "clean".
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The constant 0 is used instead of NULL in '__ACCESS_ONCE' as a
compile-time check to detect non-scalar types; its usage for this
purpose is deviated.
Furthermore, the 'typeof_field' macro is introduced as a general way
to access the type of a struct member without declaring a variable
of struct type. Both this macro and 'sizeof_field' are moved to
'xen/macros.h'.
No functional change intended.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Given its use in the declaration
'DECLARE_BITMAP(features, IOMMU_FEAT_count)' the argument
'bits' has essential type 'enum iommu_feature', which is not
allowed by the Rule as an operand to the addition operator
in macro 'BITS_TO_LONGS'.
This construct is deviated with a deviation comment.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The purpose of this macro is to encapsulate the well-known expression
'x & -x' that in 2's complement architectures on unsigned integers will
give a mask where only the least significant nonzero bit of 'x' is set,
or 0 if none are set.
A deviation for ECLAIR is also introduced.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add 21.1 and 21.2, with a longer comment to explain how strategy with
leading underscores and why we think we are safe today.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Add MISRA C Rules 11.1, 11.2, 11.3, 11.6 as discussed.
Explicitly add in the notes that conversions to integer types are
permitted if the destination type has enough bits to hold the entire
value. GCC gives enough guarantees in terms of preserving the bit
content in such situations.
Also allow for bool conversions (e.g. to check if a function point is
valid).
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
sphinx-build reports:
docs/designs/launch/hyperlaunch.rst: WARNING: document isn't included in any toctree
docs/designs/launch/hyperlaunch-devicetree.rst: WARNING: document isn't included in any toctree
docs/misc/xen-makefiles/makefiles.rst: WARNING: document isn't included in any toctree
docs/misra/C-language-toolchain.rst: WARNING: document isn't included in any toctree
docs/misra/C-runtime-failures.rst: WARNING: document isn't included in any toctree
docs/misra/documenting-violations.rst: WARNING: document isn't included in any toctree
docs/misra/exclude-list.rst: WARNING: document isn't included in any toctree
docs/misra/xen-static-analysis.rst: WARNING: document isn't included in any toctree
Create an up-to-date index.rst in misra/ create an "unsorted docs" section at
the top level to contain everything else. They can be re-filed at a later
date.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
sphinx-build reports:
docs/misra/exclude-list.rst:47: WARNING: Unexpected indentation.
docs/misra/exclude-list.rst:50: WARNING: Inline emphasis start-string without end-string.
Nested lists require newlines as delimiters, and * either needs escaping, or
put in a literal block.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
sphinx-build reports:
docs/designs/launch/hyperlaunch.rst:111: WARNING: Title underline too short.
docs/designs/launch/hyperlaunch.rst:203: WARNING: Unexpected indentation.
docs/designs/launch/hyperlaunch.rst:216: WARNING: Unexpected indentation.
Nested lists require newlines as delimiters.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
These 3 Kconfig docs were imported from Linux erroneously. They are
GPL-2.0-only in Linux, but have no SPDX tag and were placed in such a way to
be included by the blanket statement saying that all RST files are CC-BY-4.0.
We should not be carrying a shadow copy of these docs. They aren't even wired
into our Sphinx docs, and anyone wanting to refer to Kconfig docs is going to
look at the Linux docs anyway. These, and more docs can be found at:
https://www.kernel.org/doc/html/latest/kbuild/
which also have corrections vs the snapshot we took.
Fixes: f80fe2b34f ("xen: Update Kconfig to Linux v5.4")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Two files are missing SDPX tags, but are covered by the blanketing license
statement in docs/README.sources saying that RST files are CC-BY-4.0
Fixes: 3c911be55f ("docs/misra: document the C dialect and translation toolchain assumptions.")
Fixes: 7211904e09 ("docs/misra: add documentation skeleton for MISRA C:2012 Dir 4.1")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Currently exclude-list.json is used by the xen-analysis tool to
remove from the report (cppcheck for now) violations from the
files listed in it, however that list can be used by different
users that might want to exclude some of the files from their
computation for many reasons.
So add a new field that can be part of each entry to link
the tool supposed to consider that exclusion.
Update exclusion_file_list.py to implement the logic and update
the documentation to reflect this change.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The current implementation of x2APIC requires to either use Cluster Logical or
Physical mode for all interrupts. However the selection of Physical vs Logical
is not done at APIC setup, an APIC can be addressed both in Physical or Logical
destination modes concurrently.
Introduce a new x2APIC mode called Mixed, which uses Logical Cluster mode for
IPIs, and Physical mode for external interrupts, thus attempting to use the
best method for each interrupt type.
Using Physical mode for external interrupts allows more vectors to be used, and
interrupt balancing to be more accurate.
Using Logical Cluster mode for IPIs allows fewer accesses to the ICR register
when sending those, as multiple CPUs can be targeted with a single ICR register
write.
A simple test calling flush_tlb_all() 10000 times on a tight loop on AMD EPYC
9754 with 512 CPUs gives the following figures in nano seconds:
x mixed
+ phys
* cluster
N Min Max Median Avg Stddev
x 25 3.5131328e+08 3.5716441e+08 3.5410987e+08 3.5432659e+08 1566737.4
+ 12 1.231082e+09 1.238824e+09 1.2370528e+09 1.2357981e+09 2853892.9
Difference at 95.0% confidence
8.81472e+08 +/- 1.46849e+06
248.774% +/- 0.96566%
(Student's t, pooled s = 2.05985e+06)
* 11 3.5099276e+08 3.5561459e+08 3.5461234e+08 3.5415668e+08 1415071.9
No difference proven at 95.0% confidence
So Mixed has no difference when compared to Cluster mode, and Physical mode is
248% slower when compared to either Mixed or Cluster modes with a 95%
confidence.
Note that Xen uses Cluster mode by default, and hence is already using the
fastest way for IPI delivery at the cost of reducing the amount of vectors
available system-wide.
Make the newly introduced mode the default one.
Note the printing of the APIC addressing mode done in connect_bsp_APIC() has
been removed, as with the newly introduced mixed mode this would require more
fine grained printing, or else would be incorrect. The addressing mode can
already be derived from the APIC driver in use, which is printed by different
helpers.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Henry Wang <Henry.Wang@arm.com>
Using enumerators declared in a named enum, such as the one modified,
as operands to arithmetic operators is not allowed by MISRA C:2012 Rule 10.1.
The enumerators of an anonymous enum can be used instead.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The aforementioned directive requires the project to supply documentation
on the measures taken towards the minimization of run-time failures.
The actual content of the documentation still needs feedback from the
community.
The 'rules.rst' file is updated accordingly to mention the newly
added documentation.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Make the command line docs match the actual implementation, and state that the
default behaviour is selected at compile time.
Fixes: 980d6acf15 ("IOMMU: make DMA containment of quarantined devices optional")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
In commit 9d267c049d ("xen/arm64: Rework the memory layout"),
we decided to require Xen to be loaded below 2 TiB to simplify
the logic to enable the MMU. The limit was decided based on
how known platform boot plus some slack.
We had a recent report that this is not sufficient on the AVA
platform with a old firmware [1]. But the restriction is not
going to change in Xen 4.18. So document the limit clearly
in docs/misc/arm/booting.txt.
[1] https://lore.kernel.org/20231013122658.1270506-3-leo.yan@linaro.org
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
With the addition of per-device quarantine page tables the sink page is now
exclusive for each device, and thus writable. Update the documentation to
reflect the current implementation.
Fixes: 14dd241aad ('IOMMU/x86: use per-device page tables for quarantining')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
This file contains the deviation that are not marked by
a deviation comment, as specified in
docs/misra/documenting-violations.rst.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Introduce a timeout for bootloader execution when running in restricted mode.
Allow overwriting the default time out with an environment provided value.
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Much like the device model depriv mode, add the same kind of support for the
bootloader. Such feature allows passing a UID as a parameter for the
bootloader to run as, together with the bootloader itself taking the necessary
actions to isolate.
Note that the user to run the bootloader as must have the right permissions to
access the guest disk image (in read mode only), and that the bootloader will
be run in non-interactive mode when restricted.
If enabled bootloader restrict mode will attempt to re-use the user(s) from the
QEMU depriv implementation if no user is provided on the configuration file or
the environment. See docs/features/qemu-deprivilege.pandoc for more
information about how to setup those users.
Bootloader restrict mode is not enabled by default as it requires certain
setup to be done first (setup of the user(s) to use in restrict mode).
This is part of XSA-443 / CVE-2023-34325
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
The x86 hypercall ABI really used to have 6-argument hypercalls. V4V, the
downstream predecessor to Argo did take 6th args.
However, the 6th arg being %ebp in the 32bit ABI makes it unusable in
practice, because that's the frame pointer in builds with frame pointers
enabled. Therefore Argo was altered to being a 5-arg hypercall when it was
upstreamed.
c/s 2f531c122e ("x86: limit number of hypercall parameters to 5") removed
the ability for hypercalls to take 6 arguments.
Update the documentation to match reality.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
During the discussions that led to the acceptance of Rule 2.1, we
decided on a few exceptions that were not properly recorded in
rules.rst. Add them now.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Add 14.3, with project-wide deviations.
Also take the opportunity to clarify that parameters of function pointer
types are expected to have names (Rule 8.2).
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
The credit scheduler tries as hard as it can to ensure that it always
runs scheduling units with positive credit (PRI_TS_UNDER) before
running those with negative credit (PRI_TS_OVER). If the next
runnable scheduling unit is of priority OVER, it will always run the
load balancer, which will scour the system looking for another
scheduling unit of the UNDER priority.
Unfortunately, as the number of cores on a system has grown, the cost
of the work-stealing algorithm has dramatically increased; a recent
trace on a system with 128 cores showed this taking over 50
microseconds.
Add a parameter, load_balance_ratelimit, to limit the frequency of
load balance operations on a given pcpu. Default this to 1
millisecond.
Invert the load balancing conditional to make it more clear, and line
up more closely with the comment above it.
Overall it might be cleaner to have the last_load_balance checking
happen inside csched_load_balance(), but that would require either
passing both now and spc into the function, or looking them up again;
both of which seemed to be worse than simply checking and setting the
values before calling it.
On a system with a vcpu:pcpu ratio of 2:1, running Windows guests
(which will end up calling YIELD during spinlock contention), this
patch increased performance significantly.
Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
Python distutils is deprecated and is going to be removed in Python
3.12. distutils.sysconfig is available as the sysconfig module in
stdlib since Python 2.7 and Python 3.2, so use that directly.
Update the README to reflect that we now depend on Python 2.7.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Javi Merino <javi.merino@cloud.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
[Regen ./configure]
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
In the Zen1 microarchitecure, there is one divider in the pipeline which
services uops from both threads. In the case of #DE, the latched result from
the previous DIV to execute will be forwarded speculatively.
This is an interesting covert channel that allows two threads to communicate
without any system calls. In also allows userspace to obtain the result of
the most recent DIV instruction executed (even speculatively) in the core,
which can be from a higher privilege context.
Scrub the result from the divider by executing a non-faulting divide. This
needs performing on the exit-to-guest paths, and ist_exit-to-Xen.
Alternatives in IST context is believed safe now that it's done in NMI
context.
This is XSA-439 / CVE-2023-20588.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
As per the last MISRA C group discussion, let's accept 11.7 (for which
we have no violations) and 11.8.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
As stated in 'docs/misra/rules.rst' the functions that are used only by
asm modules do not need to conform to MISRA C:2012 Rule 8.4.
The deviations are carried out with a SAF comment.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
10.1 with several caveats, described in the notes.
10.3 and 10.4 as "aspirational" guidelines, as clarified in the notes.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Not displaying INFO messages by default on release builds is not
helpful, as messages of that level are relevant for hypervisor
operation. For example messages related to livepatches applied and
reverted are of INFO level.
Custom builds that require less verbose output can adjust it using the
command line, but attempt to provide all relevant information by
default on release builds.
Adjust the loglevel of printks that don't have an associated level to
INFO instead of WARNING, since INFO will now be printed by default on
all builds.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Stefano Stabellini