The original commit showed a ~6% regression in a benchmark. The call to
align_timer(firsttick, period) rounds firsttick up to the next mutiple
of the period, if firsttick % period != 0:
align_timer(0, period) -> 0
align_timer(1, period) -> period
align_timer(period, period) -> period
align_timer(period + 1, period) -> 2 * period
So adding the period (sampling_rate) before calling align_timer() will
in most cases incease the expiration to 2 * period (sampling_rate) (the
exception being firsttick % period == 0). This longer timer slows the
reaction time of the algorithm.
This reverts commit a0ed5bcfbe, just without
re-introducing the style issues that were there.
Fixes: a0ed5bcfbe ("xen/cpufreq: fix usages of align_timer() in the on-demand governor")
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Unprivileged callers better wouldn't be in the position of figuring out
domain existence from error codes. Adjust the respective path sitting
ahead of XSM checks to produce -EPERM in such cases, just like the
subsequent XSM check would yield.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
HAS_PIRQ is selected by x86 only, and that's expected to remain that way.
Avoid the #ifdef needed by moving the logic to arch_do_domctl(). Leverage
"currd" being available as a local variable there while doing so.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Anthony reported a boot-time assertion in init_xen_time() via efi_get_time()
-> efi_rs_enter() in vcpu_save_fpu() on a Broadwell-D system:
Assertion '!is_idle_vcpu(v)' failed at arch/x86/i387.c:195
This became fragile after the lazy-FPU removal cleanup series:
In 1792bb9a99 ("x86: Cleanup cr0.TS flag handling"),
efi_rs_enter() was changed from save_fpu_enable() to vcpu_save_fpu(curr),
which unconditionally asserts !is_idle_vcpu(v)
so an EFI runtime call in idle context now asserts.
Likewise, in dba44e0512 ("x86: Remove fully_eager_fpu"),
efi_rs_leave() was changed to call vcpu_restore_fpu(curr),
which has the same assertion and can fail for the same reason.
Guard both EFI runtime FPU calls with !is_idle_vcpu() to skip save/restore
for idle vCPUs, which don't have an FPU context to save/restore,
much like the calls are guarded in __context_switch(),
where save/restore is done only for non-idle vCPUs.
Fixes: 1792bb9a99 ("x86: Cleanup cr0.TS flag handling")
Fixes: dba44e0512 ("x86: Remove fully_eager_fpu")
Reported-by: Anthony PERARD <anthony.perard@vates.tech>
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Bernhard Kaindl <bernhard.kaindl@citrix.com>
Tested-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
The configuration uses a mix of dashes and underscores, which is irritating to
develop for. Switch to using the underscore form consistently; it is the more
common form and it has the benefit that it allows splitting on dashes to work
sensibly.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Denis Mukhin <dmukhin@ford.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Perform standard syntax cleanup and make it a non-root container. Switch yajl
for json-c given the deprecation of the former. Drop dev86 which is an
x86-only dependency, and QEMU dependencies as we don't build QEMU in this
environment any more.
When updating the job names, also rename some for consistency so the arm64
fragment comes before the compiler.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Denis Mukhin <dmukhin@ford.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Perform standard syntax cleanup and make it a non-root container. Switch yajl
for json-c given the deprecation of the former.
Add an x86_64 suffix for naming consistency with everything else.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Denis Mukhin <dmukhin@ford.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
This container is tied to gitlab-runner environment in the RPis driving the
test systems, not a specific version of Alpine. Intentionally give it a
generic name so it need not change in the future.
Switch to Alpine 3.24 right away, as it doesn't interact with the 3.18 builds
under test.
The container needs to remain a root container. By no longer using the
arm64v8 build container for dual-purpose, we can finally make the build
containers be non-root.
No practical change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Denis Mukhin <dmukhin@ford.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
GCC 15.2 with Alpine Linux 3.24 fails with -Werror=nonnull, complaining that
we're calling bzero(NULL, 128).
This is a legitimate diagnostic. xenalyze has it's own error() function
shadowing the standard library one, and can in principle return when p is
NULL.
Extend the check in error() with ERR_MAX_TOLERABLE to short circuit the
variable tolerance check.
Suggested-by: Anthony PERARD <anthony.perard@vates.tech>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
In order to avoid serialising the testing on both boards, the runner
configuration is being adjusted.
Have the .xilinx-arm64 and .xilinx-x86_64 templates choose the board directly
using a more specific tag.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Victor Lira <victorm.lira@amd.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
The container is tied to the runner, not a version of Ubuntu. Intentionally
give it a generic name so it need not change in the future.
Apply standard cleanup to the dockerfile, except that it must continue to be a
root container to drive real hardware. Explicitly install ca-certificates to
compensate for --no-install-recommends.
No practical change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Rename it to have an x86_64 suffix, updating the build job names and scheduled
rebuild task.
Apply standard cleanups. Trim the package list down to what is actually
needed. Archlinux's base-devel contains most libraries, but some of the
listed packages have never been dependenices for Xen, and a lot are QEMU
dependenices which aren't useful owing to the lack of the ninja package.
This shrinks the container from 533MB to 380MB.
No practical change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Today the inline tracking of the stub page is problematic. 0xcc is used to
indicate unused, but it is also a "clear value." A !CONFIG_PV build or
when running with FRED support will not populate the LSTAR/CSTAR stubs at
CPU bringup. If a CPU is then offlined, the stubs page will be freed as
its content will be all 0xcc, regardless of the stubs page still begin
referenced by other CPUs.
The new approach uses a global, CPU-indexed dynamically allocated array of
stub addresses. However, to handle NUMA aware allocations, we cannot
allocate all the memory in advance because of the NUMA dependency. Take
advantage of the fact that Xen will attempt to contiguously pack CPUs on
the same NUMA node (see normalise_cpu_order()), and on CPU bringup use the
same stubs page the previous CPU did if suitable. Note the code would
still function properly even if CPUs from NUMA nodes are not contiguously
packed, it just consumes more memory.
Stubs pages are no longer freed. They remain referenced in the global
CPU-indexed array and are re-used if the CPU is re-onlined.
The stubs array doesn't have an explicit lock. During boot it's accessed
single threaded. During runtime, &cpu_add_remove_lock serializes access.
Fixes: 7a66ac8d16 ("x86: move syscall trampolines off the stack")
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Remove the RTDS scheduler specific entry in MAINTAINERS.
The effective changes will be:
- Meng will no longer be a maintainer. His last Ack on a RTDS patch
was given in 2019, since then I can't remember having seen any
reaction on a RTDS patch.
- I'll be made a maintainer of this scheduler. Dario has indicated
that he doesn't have lots of cycles for doing reviews, so he would
be grateful for not being effectively the only maintainer of the
RTDS scheduler.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Convert 'free' macro in 'decompress.h' from object-like to function-like
form.
The object-like macro '#define free xfree' performs unconditional text
replacement, causing conflicts with identifiers named 'free', such as
struct fields in 'page_info' unions defined in 'xen/arch/arm/include/asm/mm.h'.
Function-like macros only match when followed by parentheses, allowing
'free' to be used both as a macro and as a struct field without conflicts.
Applying function-like form to 'malloc', 'large_malloc' and 'large_free'
ensures consistent macro style.
Additionally moved 'large_{malloc,free}' past the #endif to reduce
redundancy.
While function-like macros prevent uses where the underlying function
identifier is needed directly, such as taking a function pointer, no
such uses exist in the current Xen codebase.
Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@epam.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Handle XEN_DOMCTL_SHADOW_OP_{CLEAN,PEEK} without taking the domctl lock.
This is safe because for these subops, the paging lock is mostly held
which prevents it from operating concurrently on the same domain. There
are some parts that are called without the paging lock held:
* hvm_mapped_guest_frames_mark_dirty() - The function itself takes a
spinlock so is protected from concurrent calls. In any case, it will
mark all the pages dirty as required.
* domain_{,un}pause() - The toolstack cannot {,un}pause the domain while
in paging_log_dirty_op() because the toolstack's pause/unpause ops have
a separate ref count.
* p2m_flush_hardware_cached_dirty() - This is called elsewhere without
the domctl lock held so holding it wouldn't achieve anything. It
should be fine as long as it is called at least once.
* log_dirty.ops->clean() - If the callback is hap_clean_dirty_bitmap(),
then it will hold the p2m lock while modifying the table. If the
callback is sh_clean_dirty_bitmap(), it will hold the paging lock
while modifying the table. In both cases, this is OK.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
It does not have side effects and is protected from concurrent changes
by the P2M read lock therefore skip taking the domctl lock.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
With LLC coloring enabled, the hardware domain memory is allocated by
allocate_hwdom_memory() rather than by using the fixed direct-map layout.
Commit de99f32635 ("device-tree: Improve hwdom memory allocation for
DMA") made that allocator prefer lower host regions. The first-bank
filter, however, still only checked the old 128MB heuristic. A low region
can satisfy that heuristic but still be too small, or otherwise
unsuitable, for the hardware-domain kernel and the DTB/initrd area to fit
in bank 0 according to the Arm placement rules.
Keep the existing first-bank size policy and add an architecture-specific
candidate check. On Arm, compute the kernel load address for the
candidate bank using the same logic as kernel_zimage_place(), verify that
the kernel range is covered by that bank, and then reuse the same
DTB/initrd placement helper as place_dtb_initrd(). The FDT is generated
later, so use the hardware-domain FDT allocation size as a conservative
upper bound for the final DTB size.
Check the candidate after capping the host region by the remaining
unassigned hardware-domain memory, so the validation is performed against
the size that would actually become bank 0.
This keeps the DMA-oriented allocation policy from de99f32635 while
preventing a too-small bank 0 from reaching place_dtb_initrd().
Make kernel_zimage_place_in_bank() return INVALID_PADDR when a
position-independent zImage cannot be placed in the supplied bank; the
real load path turns this into a panic, while the hwdom candidate check
uses it to reject the bank.
Fixes: de99f32635 ("device-tree: Improve hwdom memory allocation for DMA")
Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
The Arm zImage loader currently computes the kernel load address and
places the DTB/initrd in one local flow. The hardware-domain memory
allocator needs to reuse those placement rules before it chooses bank 0,
but open-coding the same calculations there would make the fix harder to
audit.
Split the existing logic into small helpers:
- kernel_zimage_place_in_bank() computes the zImage load address for a
given bank.
- first_bank_can_fit_modules() checks the aggregate first-bank
footprint.
- find_dtb_initrd_placement() chooses the DTB/initrd location within a
known bank and kernel range.
Rename place_modules() to place_dtb_initrd() so the code distinguishes
the kernel image from the DTB/initrd placement area. Also update the
comments linking the hypervisor and toolstack placement paths.
While moving the code, spell the 2MB alignment mask with MB(2) rather
than open-coding (2 << 20). This is mechanical and keeps the generated
value unchanged.
The caller still panics in the same cases as before, so this is intended
to be behavior preserving.
Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Neither current nor curr_vcpu per-CPU fields accurately track which
page-tables are loaded. There are corner cases when dealing with shadow
paging failures that switch to the idle vCPU page-tables without changing
current or curr_vcpu per-CPU fields.
Introduce a new per-CPU field that attempts to track which vCPU page-tables
are loaded. Update such tracking when cr3 is changed, and do so in a
region with interrupts disabled, as to avoid handling interrupts with a
mismatch between the vCPU tracking field and the loaded page-tables.
As a result of this newly more accurate tracking the mapcache override
functionality can be removed: the dom0 PV builder was the only user of it,
and it's updated here to properly signal which vCPU page-tables are loaded
in the calls to switch_cr3_cr4().
Note the EFI page-tables have the Xen owned L4 slots copied from the idle
page-tables, so for the effects of the mapcache the EFI page-tables could
use the idle mapcache if it had one. Pass the idle vCPU in the
switch_cr3_cr4() call that switches to the runtime EFI page-tables.
There are known issues with the use of mapcache in NMI context. This patch
does not alter the behaviour.
This is CVE-2026-42488 / XSA-494.
Fixes: fb0ff49fe9 ("x86/shadow: defer releasing of PV's top-level shadow reference")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
A number of CPUs developed by Arm suffer from errata whereby a broadcast
TLBI + DSB sequence may complete before the global observation of writes
which are translated by an affected TLB entry. This can lead to memory
corruption and potential privilege escalation.
These errata ONLY affect the completion of memory accesses which have
been translated by an invalidated TLB entry, and these errata DO NOT
affect the actual invalidation of TLB entries. TLB entries are removed
correctly.
To mitigate this issue, Arm recommends that software follows each
TLBI+DSB sequence with an additional TLBI+DSB, which will ensure that
all memory write effects affected by the first TLBI have been globally
observed.
The ARM64_WORKAROUND_REPEAT_TLBI workaround is sufficient to mitigate the
issue. Enable this workaround for affected CPUs.
This is XSA-493 / CVE-2025-10263.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Julien Grall <julien@xen.org>
Add processor definitions for C1-Premium. These will be used for errata
detection in subsequent patches.
These values can be found in the C1-Premium TRM:
https://developer.arm.com/documentation/109416/0100/
... in section A.5.1 ("MIDR_EL1, Main ID Register").
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Julien Grall <julien@xen.org>
Add processor definitions for C1-Ultra. These will be used for errata
detection in subsequent patches.
These values can be found in the C1-Ultra TRM:
https://developer.arm.com/documentation/108014/0100/
... in section A.5.1 ("MIDR_EL1, Main ID Register").
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Julien Grall <julien@xen.org>
Synchronize with Linux kernel 7.0 definitions for the following CPUs:
- Cortex-A76AE,
- Cortex-A78AE,
- Cortex-X1C,
- Cortex-X3,
- Neoverse-V2,
- Cortex-X4,
- Neoverse-V3AE,
- Neoverse-V3,
- Cortex-X925.
These will be used for errata detection in subsequent patches.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Julien Grall <julien@xen.org>
The only locking required here is that between checking d->target and
setting it. To avoid the need for an explicit lock, use cmpxchgptr() to
update d->target.
Move the handling not only ahead of acquiring the lock, but also ahead
of the XSM check, leveraging that the sub-op has its own hook.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Integrate the checking with xsm_domctl(). As a positive side effect,
permissions are then checked at the same early point with and without
Flask. As the DT device path needs fetching earlier (but must not be
double fetched), cache it in a private field of the public interface
struct.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
iommu_get_device_group() uses its own locking. Thus, with caller side
locking irrelevant, it can as well be called with the domctl lock not
held.
Move the handling not only ahead of acquiring the lock, but also ahead
of the XSM check, leveraging that the sub-op has its own hook.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Integrate the checking with xsm_domctl(), now that it has the full op
struct passed. As a positive side effect, permissions are then checked at
the same early point with and without Flask.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Integrate the checking with xsm_domctl(), now that it has the full op
struct passed. As a positive side effect, permissions are then checked at
the same early point with and without Flask.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Subsequently some sub-ops will want to inspect their sub-sub-ops. Plus
this way we don't need to pass SSIDref separately anymore for
domain_create.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Integrate the checking with xsm_domctl(). Care needs to be taken with the
GET_VERSION sub-op, which may be invoked with DOMID_INVALID, and which has
been (and continues to be) bypassing XSM checking.
Since the latter two parameters were unused, monitor_domctl() invoking the
hook was actually redundant with the earlier xsm_domctl() (as can be seen
nicely from the hunks changing xsm/flask/hooks.c).
As a positive side effect, permissions are then checked at the same early
point with and without Flask.
While folding XEN_DOMCTL_monitor_op and XEN_DOMCTL_vm_event_op in
flask_domctl(), also fold in XEN_DOMCTL_set_access_required.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
With dedicated locking added, the domctl lock isn't required here anymore.
As the GSI handling is in arch-specific code (x86 only), no code is being
moved there; the 2nd invocation of arch_do_domctl() is re-used. Move the
re-purposed (XSM_HOOK -> XSM_PRIV, as xsm_domctl() is now bypassed)
dedicated XSM checks as early as possible.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
With dedicated locking added, the domctl lock isn't required here anymore.
As the I/O port handling is in arch-specific code (x86 only), no code is
being moved, but the 2nd invocation of arch_do_domctl() is re-used. Move
the re-purposed dedicated XSM checks as early as possible.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
With dedicated locking added, the domctl lock isn't required here anymore.
(It also already isn't used when pt_irq_{create,destroy}_bind() are
invoked for PVH Dom0.) As the handling is in arch-specific code, no code
is being moved, but the 2nd (extensible to other sub-ops like the ones
here) invocation of arch_do_domctl() is being re-used.
This is part of XSA-492.
Fixes: fda49f9b3f ("Add build option to allow more hypercalls from stubdoms")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Acked-by: Julien Grall <julien@xen.org>
With dedicated locking added, the domctl lock isn't required here anymore.
As the handling is in arch-specific code (x86 only), almost no code is
being moved, but a 2nd (extensible to other sub-ops) invocation of
arch_do_domctl() is being added. Move just the re-purposed dedicated XSM
check as early as possible.
In flask_domctl() don't put #ifdef around the moved case label.
This is part of XSA-492.
Fixes: fda49f9b3f ("Add build option to allow more hypercalls from stubdoms")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
With dedicated locking added, the domctl lock isn't required here anymore.
Move the re-purposed dedicated XSM check as early as possible.
Minimal "modernization": Switch "add" to bool and use %pd in log messages.
This is part of XSA-492.
Fixes: fda49f9b3f ("Add build option to allow more hypercalls from stubdoms")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
It's used twice in entirely different situations. The use in do_domctl()
wants to become an ordinary XSM_DM_PRIV invocation, while the one in vPCI
code need to remain XSM_HOOK (it may plausibly become XSM_TARGET). For
Flask, the same backing function will continue to be used for the time
being.
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
In order to be able to pull at least the XEN_DOMCTL_{,un}bind_pt_irq
handling out of the domctl-locked region, a separate (per-domain) lock is
needed to synchronize in particular with XEN_DOMCTL_{irq,gsi}_permission.
Locking is added only as far as domctl-s are affected. Uses presently
outside of the domctl lock may want dealing with subsequently (perhaps
limited to non-__init code).
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Julien Grall <julien@xen.org>
In order to be able to pull at least the XEN_DOMCTL_ioport_mapping
handling out of the domctl-locked region, the new separate (per-domain)
lock is used to synchronize in particular with
XEN_DOMCTL_ioport_permission.
Locking is added only as far as domctl-s are affected. Uses presently
outside of the domctl lock may want dealing with subsequently (perhaps
limited to non-__init code).
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
In order to be able to pull at least the XEN_DOMCTL_iomem_mapping handling
out of the domctl-locked region, a separate (per-domain) lock is needed to
synchronize in particular with XEN_DOMCTL_iomem_permission.
Locking is added only as far as domctl-s are affected. Uses presently
outside of the domctl lock may want dealing with subsequently (perhaps
limited to non-__init code).
This is part of XSA-492.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
get_domain_state() uses its own locking. Thus, with caller side locking
irrelevant, it can as well be called with the domctl lock not held.
Move the handling not only ahead of acquiring the lock, but also ahead
of the XSM check, leveraging that the sub-op has its own hook.
This is part of XSA-492.
Fixes: 3ad3df1bd0 ("xen: add new domctl get_domain_state")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
When DOMID_INVALID is passed, the dom exec handler lock is being taken
without any check that the domain is even allowed to take the lock. This
allows for an unauthorized domain to DoS the get_domain_state domctl op.
Move to consider the op effectively being called against the hypervisor.
Thus it is the target of the call being invoked to identify the last
domain with a state change. The subsequent check of whether the source
domain is allowed the state of the last domain to change state is still
relevant.
This is part of XSA-492.
Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
getdomaininfo() is not called under consistently the same lock. Thus,
with caller side locking irrelevant, it can as well be called with the
domctl lock not held. (Callers not pausing the domain they want to
retrieve information for already need to be aware that not all of the
data returned can be relied on as being consistent; most data will also
be stale by the time the caller gets to look at it.)
Move the handling not only ahead of acquiring the lock, but also ahead
of the XSM check, leveraging that the sub-op has its own hook.
While moving, convert an assignment to an assertion: The domain in
question was determined from the field which previously was "updated".
This is part of XSA-492.
Fixes: 5513bd0b46 ("add xenstore domain flag to hypervisor")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Subsequently XEN_DOMCTL_getdomaininfo will want to invoke the function
without holding a lock, thus allowing parallel execution of potentially
many instances. As was learned from 228ab9992f ("domctl: improve
locking during domain destruction"), reverted by d0887cc6b1, such
parallelism can result in severe lock contention on any (previously)
inner lock. To avoid taking that risk replace the use of the scheduler
lock in vcpu_runstate_get() by a newly introduced sequence counter.
Convert the "no lock if current" property to "use a local counter
instance", thus guaranteeing the loop to exit after the first iteration.
Skeleton and commentary of the seqcount implementation based on /
derived from Linux 6.11-rc.
To have runstate_seq placed next to runstate in struct vcpu, without
introducing a new obvious padding hole, yet while keeping the latter
adjacent to runstate_guest{,_area} as well, move runstate down a little.
This is part of XSA-492.
Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
XEN_DOMCTL_ioport_mapping is usable by DM stubdoms, and hence we can't
assume the list to be left unaltered while the guest (really: the
hypervisor on behalf of the guest) is accessing it.
This is XSA-491 / CVE-2026-42487.
Fixes: 192c4dabc3 ("domctl and p2m changes for PCI passthru")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Jason Andryuk