On a stress test running 1000 VMs flamegraphs have shown that
`oxenstored` spends a large amount of time in `Hashtbl.copy` and the GC.
Hashtable complexity:
* read/write: O(1) average
* copy: O(domains) -- copying the entire table
Map complexity:
* read/write: O(log n) worst case
* copy: O(1) -- a word copy
We always perform at least one 'copy' when processing each xenstore
packet (regardless whether it is a readonly operation or inside a
transaction or not), so the actual complexity per packet is:
* Hashtbl: O(domains)
* Map: O(log domains)
Maps are the clear winner, and a better fit for the immutable xenstore
tree.
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
This patch addresses a behavior discrepancy in the handling of altp2m views,
where upon the creation and subsequent EPT violation, the page access
permissions were incorrectly inherited from the hostp2m instead of respecting
the altp2m default_access.
Previously, when a new altp2m view was established with restrictive
default_access permissions and activated via xc_altp2m_switch_to_view(),
it failed to trigger an event on the first access violation. This behavior
diverged from the intended mechanism, where the altp2m's default_access
should dictate the initial permissions, ensuring proper event triggering on
access violations.
The correction involves modifying the handling mechanism to respect the
altp2m view's default_access upon its activation, eliminating the need for
setting memory access permissions for the entire altp2m range (e.g. within
xen-access.c). This change not only aligns the behavior with the expected
access control logic but also results in a significant performance improvement
by reducing the overhead associated with setting memory access permissions
across the altp2m range.
Signed-off-by: Petr Beneš <w1benny@gmail.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
All architectures have copy&pasted bad logic from x86.
OFFSET() having a trailing semi-colon within the macro expansion can be a
problematic pattern. It's benign in this case, but fix it anyway.
Perform style fixes for the other macros, and tame the mess of BLANK()
position to be consistent (one BLANK() after each block) so the intermediate
form is legible too.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Shawn Anastasio <sanastasio@raptorengineering.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Implement the in-code suppression comment at the end of the line.
Now it is possible to add a Xen deviaiton comment with the syntax
described in the docs at the end of the line affected by the
violation, to deviate it.
Eclair natively supports it, so the translation for the tool will
be straighforward, but the other tool needs to translate an
occurrence of the tag into a suppressino comment at the end of the
previous line, this will have a corner case where the line number
1 of the file can't be deviated in this way for such tools.
Updated documentation.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Change the code in tag_database.py to substitute only the SAF-*
comment instead of replacing the line.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Use named group for the regex matching a tag identifier, this
is done to ease retrieving the matching group instead of using
an index.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
The type not being used in do_bug_frame() is suspicious. Apparently
that's solely because the type uses a pointer-to-const parameter,
when so far run_in_exception_handler() wanted functions taking pointer-
to-non-const. Expand use of const, in turn requiring common code's
do_bug_frame() as well as [gs]et_irq_regs() to also gain const. This
then brings the former function also closer to the common one, with
Arm's use of vaddr_t remaining as a difference.
While there also replace the bogus use of hard tabs in [gs]et_irq_regs()
(I clearly didn't mean to put it in like this).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The only place it was needed is in the spurious handler, and there we
can use get_irq_regs() instead.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
It's not needed anymore. This is in preparation of dropping the register
parameters from IRQ handler functions.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
In preparation for further removal of regs parameters, drop it here. In
the two places where it's actually needed, retrieve IRQ context if
available, or else guest context.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
In preparation of dropping the register parameters from
serial_[rt]x_interrupt() and in turn from IRQ handler functions,
register state needs making available another way for the few key
handlers which need it. Fake IRQ-like state.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
When re-working library call wrapping the sed invocation didn't account
for all sources living in the parent directory when building the 32-bit
harness binary.
Fixes: 6fba45ca3b ("x86emul: rework wrapping of libc functions in test and fuzzing harnesses")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
EVEX.R' is not ignored in 64-bit code when encoding a GPR or mask
register. While for mask registers suitable checks are in place (there
also covering EVEX.R), they were missing for the few cases where in
EVEX-encoded instructions ModR/M.reg encodes a GPR. While for VPEXTRW
the bit is replaced before an emulation stub is invoked, for
VCVT{,T}{S,D,H}2{,U}SI this actually would have led to #UD from inside
an emulation stub, in turn raising #UD to the guest, but accompanied by
log messages indicating something's wrong in Xen nevertheless.
Fixes: 001bd91ad8 ("x86emul: support AVX512{F,BW,DQ} extract insns")
Fixes: baf4a376f5 ("x86emul: support AVX512F legacy-equivalent scalar int/FP conversion insns")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
__get_user_bad() and __put_user_bad() are undefined symbols used
to assert the unreachability of a program point:
a call to one of such functions is optimized away if it is considered
unreachable by the compiler. Otherwise, a linker error is reported.
In accordance with the purpose of such constructs:
1) add the attribute noreturn to __get_user_bad() and __put_user_bad();
2) change return type of __get_user_bad() to void (returning long is a
leftover from the past).
Point (1) meets the requirements to deviate MISRA C:2012 Rule 16.3
("An unconditional break statement shall terminate every switch
clause") since functions with noreturn attribute are considered
as allowed terminals for switch clauses.
Point (2) addresses several violations of MISRA C:2012 Rule 17.7
("The value returned by a function having non-void return type
shall be used").
While there also zap "extern".
No functional change.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Because of using "-include", failure to (re)build auto.conf (with
auto.conf.cmd produced as a secondary target) won't stop make from
continuing the build. Arrange for it being possible to drop the - from
Rules.mk, requiring that the include be skipped for tools-only targets.
Note that relying on the inclusion in those cases wouldn't be correct
anyway, as it might be a stale file (yet to be rebuilt) which would be
included, while during initial build, the file would be absent
altogether.
Fixes: 8d4c17a90b ("xen/build: silence make warnings about missing auto.conf*")
Reported-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
In xen-9pfsd fill_data() va_end() needs to be called before returning.
Coverity Id CID 1592145
Fixes: bcec59cf7f ("tools/xen-9pfsd: add 9pfs version request support")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Some headers are the same as asm-generic verions of them
so use them instead of arch-specific headers.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Along the line with observations in the context of XSA-448, no field in
struct gnttab_copy_ptr is relevant when no data is to be copied, much
like e.g. the pointers passed to memcpy() are irrelevant (and would
never be "validated") when the passed length is zero.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
According to comments (and experiments) qemu-xen cannot handle memory
reolcation done by hvmloader. The code was already disabled when running
qemu-xen in dom0 (see libxl__spawn_local_dm()), but it was missed when
adding qemu-xen support to stubdomain. Adjust libxl__spawn_stub_dm() to
be consistent in this regard.
Reported-by: Neowutran <xen@neowutran.ovh>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
At the moment, the hardware domain vUART is always compiled in. In the
spirit of fine granular configuration, make it optional so that the
feature can be disabled if not needed. This UART is not exposed (e.g.
via device tree) to a domain and is mostly used to support special use
cases like Linux early printk, prints from the decompressor code, etc.
Introduce Kconfig option CONFIG_HWDOM_VUART, enabled by default (to keep
the current behavior) and use it to protect the vUART related code.
Provide stubs for domain_vuart_{init,free}() in case the feature is
disabled. Take the opportunity to add a struct domain forward declaration
to vuart.h, so that the header is self contained.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Tested-by: Luca Fancellu <luca.fancellu@arm.com>
The 'struct dev_archdata' is exclusively used within 'struct device',
so it could be merged into 'struct device.'
After the merger, it is necessary to update the 'dev_archdata()'
macros and the comments above 'struct arm_smmu_xen_device' in
drivers/passthrough/arm/smmu.c.
Additionally, it is required to update instances of
"dev->archdata->iommu" to "dev->iommu".
Suggested-by: Julien Grall <julien@xen.org>
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
The following changes were done as a result of switching to
asm-generic/device.h:
* DEVICE_GIC was renamed to DEVICE_INTERRUPT_CONTROLLER according
to definition of enum device_class in asm-generic/device.h.
* acpi-related things in Arm code were guarded by #ifdef CONFIG_ACPI
as struct acpi_device_desc was guarded in asm-generic, also functions
acpi_device_init() was guarded too as they are using structure
acpi_device_desc inside.
* drop arm/include/asm/device.h and update arm/include/asm/Makefile
to use asm-generic/device.h instead.
As 'struct device_desc' is protected by CONFIG_HAS_DEVICE_TREE,
_sdevice, _edevice, device_init(), and device_get_class should also be
protected.
However, this protection was not implemented because Arm always has
CONFIG_HAS_DEVICE_TREE=y at the moment.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Arm, PPC and RISC-V introduce the same things in asm/device.h, so
generic device.h was introduced.
Arm's device.h was taken as a base with the following changes:
- #ifdef ACPI related things.
- Rename #ifdef guards.
- Add SPDX tag.
- #ifdef CONFIG_HAS_DEVICE_TREE related things.
- #ifdef-ing iommu related things with CONFIG_HAS_PASSTHROUGH.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
On many entries we push 8-bytes zero and exception constants are
small so we can just write a single byte saving 3 bytes for
instruction.
With ENDBR64 this reduces the size of many entry points from 32 to
16 bytes (due to alignment).
The push and the mov are overlapping stores either way. Swapping
between movl and movb will make no difference at all on performance.
Similar code is already used in autogen_stubs.
Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Allow administrators to control whether Xen grant mappings for
the virtio disk devices should be used. By default (when new
parameter is not specified), the existing behavior is retained
(we enable grants if backend-domid != 0).
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
The `which` command is not standard, may not exist on the build host,
or may not behave as expected by the build system. It is recommended
to use `command -v` to find out if a command exist and have its path,
and it's part of a POSIX shell standard (at least, it seems to be
mandatory since IEEE Std 1003.1-2008, but was optional before).
Fixes: c8a8645f1e ("xen/build: Automatically locate a suitable python interpreter")
Fixes: 3b47bcdb6d ("xen/build: Use a distro version of figlet")
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
It's not obvious from just the function name whether the incremented value will
be stored in the parameter, or returned to the caller. That has leads to bugs
in the past as callers may assume the incremented value is stored in the
parameter.
Add the __must_check attribute to the function to easily spot callers that
don't consume the returned value, which signals an error in the caller logic.
No functional change intended.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
At the moment the fixmap slots are prefixed differently between arm and
x86.
Some of them (e.g. the PMAP slots) are used in common code. So it would
be better if they are named the same way to avoid having to create
aliases.
I have decided to use the x86 naming because they are less change. So
all the Arm fixmap slots will now be prefixed with FIX rather than
FIXMAP.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Elias El Yandouzi <eliasely@amazon.com>
Reviewed-by: Henry Wang <Henry.Wang@arm.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add the attach request of the 9pfs protocol. This introduces the "fid"
scheme of the 9pfs protocol.
As this will be needed later, use a dedicated memory allocation
function in alloc_fid() and prepare a fid reference count.
For filling the qid data take the approach from the qemu 9pfs backend
implementation.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add the version request of the 9pfs protocol. For the version use the
"9P2000.u" variant, as it is supported by Mini-OS and Linux.
For the request parsing add all format items needed even in future in
order to avoid code churn for those additions later.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add support for generation a 9pfs protocol response via a format based
approach.
Strings are stored in a per device string buffer and they are
referenced via their offset in this buffer. This allows to avoid
having to dynamically allocate memory for each single string.
As a first user of the response handling add a generic p9_error()
function which will be used to return any error to the client.
Add all format parsing variants in order to avoid additional code churn
later when adding the users of those variants. Prepare a special case
for the "read" case already (format character 'D'): in order to avoid
adding another buffer for read data support doing the read I/O directly
into the response buffer.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add the transport layer of 9pfs. This is basically the infrastructure
to receive requests from the frontend and to send the related answers
via the rings.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add "xen-9pfsd", a new 9pfs daemon meant to support infrastructure
domains (e.g. xenstore-stubdom) to access files in dom0.
For now only add the code needed for starting the daemon and
registering it with Xenstore via a new "libxl/xen-9pfs/state" node by
writing the "running" state to it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Today the CODING_STYLE contains a section "Handling unexpected
conditions" specific to the hypervisor. This section is kind of
misplaced for a coding style. It should rather be part of a "Coding
best practices" guide.
Add such a guide as docs/process/coding-best-practices.pandoc and
move the mentioned section from CODING_STYLE to the new file, while
converting the format to pandoc.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
mfn_add() doesn't store the incremented value in the parameter, and instead
returns it to the caller. As a result, the loop in iommu_unity_region_ok()
didn't make progress. Fix it by storing the incremented value.
Fixes: e45801dea1 ('iommu/x86: introduce a generic IVMD/RMRR range validity helper')
Coverity-ID: 1592056
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
It's located in libxl_domain_build_info, not libxl_domain_create_info.
Fixes: 45ba9a7d76 ("tools/[lib]xl: Add vmtrace_buf_size parameter")
Signed-off-by: Petr Beneš <w1benny@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add a command line option to xentop to be able to display dom0 first, on top of the list.
This is unconditional, so sorting domains with the S option will also ignore dom0.
Signed-off-by: Cyril Rébert (zithro) <slack@rabbit.lu>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Edwin Török
Petr Beneš
Andrew Cooper
Luca Fancellu
Jan Beulich
Federico Serafini
Juergen Gross
Frediano Ziglio
Oleksii Kurochko
Marek Marczykowski-Górecki
Michal Orzel
Oleksandr Tyshchenko
Anthony PERARD
Roger Pau Monné
Julien Grall
Cyril Rébert