cpumask_to_xenctl_bitmap() may return errors. Clearing the error indicator
of an earlier such call by a (successful) later call is misleading the
caller. For "set", keep setting soft affinity if the hard affinity copy-
back fails; only accumulate respective errors.
While fiddling with return values, also drop a redundant clearing of
"ret". This eliminates a Misra C:2012 rule 2.2 ("There shall be no dead
code") violation.
Fixes: 6e4ecc6d58 ("sched: DOMCTL_*vcpuaffinity works with hard and soft affinity")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: 6a21252a74
master date: 2026-06-18 10:02:34 +0200
There is a 3rd path which should have gained an is_zen6_uarch() check to
exclude Zen6 from entrysign mitigations.
Fixes: bd15fdedaf ("x86/ucode: Exclude Zen6 from entrysign mitigations")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: 6ba5e9c7b8
master date: 2026-06-16 18:33:39 +0100
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>
master commit: 4f2c223c59
master date: 2026-06-12 12:00:12 +0200
Adjust the mask calculation in case the last range is merged with the
previous one, as then the mask must be calculated from the previous range,
which the current one has been merged into.
Instead of fixing the off-by-one in place, move the calculation of the bit
change mask to the next loop, after the ranges have been merged. This
simplifies the logic by consolidating mask calculation in a single place,
possibly making it less error prone in the future.
Also add a test case that triggers the bug being fixed by this commit.
Fixes: c5c45bcbd6 ("pdx: introduce a new compression algorithm based on region offsets")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: edf942201d
master date: 2026-06-09 11:43:24 +0200
Per PCI Firmware 3.3 specification, section 4.1.2, ECAM space must be
reserved by declaring a motherboard resource, but there's no requirement to
mention it in E820. The specification additionally states that: the
resources can optionally be returned in Int15 E820h or EFIGetMemoryMap as
reserved memory.
Recent Lenovo systems have been found to have the MMCFG region in an
E820 hole, which looks to be technically spec compliant, but is rejected
by Xen.
The logic was introduced in Linux in 2006 as 946f2ee5c731 ("[PATCH]
i386/x86-64: Check that MCFG points to an e820 reserved area"). This was
picked up by Xen when MCFG support was added in 3b35911d70 ("Enable pci
mmcfg and ATS for x86_64"). Apply an approach similar to what Linux has
done in 199f968f1484 ("x86/pci: Skip early E820 check for ECAM region") and
relax the strict reserved region checking so it's only done for firmware
manufactured prior to 2016. For firmware from 2016 and newer allow MCFG
region to reside in holes on the memory map. Note Xen is still more strict
than Linux however, as it will refuse to use MCFG regions that overlap with
memory map regions different than reserved.
When dom0 boots it can prevent access to misconfigured MCFG regions by
using the PHYSDEVOP_pci_mmcfg_reserved hypercall. This brings Xen's early
usage of MCFG (prior to ACPI AML parsing) more in line with the
implementation in Linux.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 87279cafc0
master date: 2026-06-05 17:40:21 +0200
reserve_offlined_page() reserves pages marked for offlining and
returns free buddies from the remaining healthy tail pages back
to the free list.
Consider an order-2 buddy (4 pages) with the following layout:
+---------------+---------------+---------------+---------------+
| head page tail page 1, tail page 2 tail page 3 |
| PFN_ORDER(pg) marked as to |
| == 2 be offlined |
+---------------+---------------+---------------+---------------+
The expected result after removing tail page 1 and returning the
remaining healthy pages to the free list would be:
+---------------+ +---------------+---------------+
| single page | offlined page | head page tail page |
| PFN_ORDER(pg) | not returned | PFN_ORDER(pg) |
| == 0 | to the heap | == 1 |
+---------------+ +---------------+---------------+
A trivial off-by-one error in the growth loop stops the growth loop
early before the tail end of the original buddy and we end up with:
+---------------+ +---------------+---------------+
| single page | offlined page | single page | single page |
| PFN_ORDER(pg) | not returned | PFN_ORDER(pg) | PFN_ORDER(pg) |
| == 0 | to the heap | == 0 | == 0 |
+---------------+ +---------------+---------------+
If the offlined page was in a much larger buddy, this would lead
to much more memory not available for higher order allocations
requiring the full tail end of the original buddy for allocation.
Fix the growth loop to correctly grow the buddy to the tail end
to make the full allocation unit available for future allocation.
Fixes: e4865c2315 ('Page offline support in Xen side')
Signed-off-by: Bernhard Kaindl <bernhard.kaindl@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 5cb7ff13ee
master date: 2026-06-05 10:08:42 +0200
reserve_offlined_page() fails to verify alignment when growing
buddies around offlined pages. Consequently, misaligned buddies
may be constructed from non-offlined page ranges and returned to
the free lists.
After a particular sequence of allocations and frees, pages
from such a misaligned buddy may be allocated more than once,
eventually triggering a Xen BUG() in alloc_heap_pages().
Fixes: e4865c2315 ('Page offline support in Xen side')
Signed-off-by: Bernhard Kaindl <bernhard.kaindl@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 71c6a62317
master date: 2026-06-05 10:08:22 +0200
Attempting to memset the whole IOMMU MMIO region to zero is dangerous to
say the least. We don't know which registers might be there, nor which
values might be safe for those registers. On a forthcoming platform doing
the zeroing of the MMIO region does put the IOMMU in a broken state, which
is not recoverable by the IOMMU initialization procedure in Xen.
Instead just zero the control register, which mimics the current behavior
with regards to how the control register is handled, and ensures the IOMU
setup is done with the unit disabled. This approach will need revisiting
in order to support Preboot DMA Protection.
Fold map_iommu_mmio_region() into its only caller, as the function body is
just an ioremap() call after the removal of the memset().
Fixes: 0700c962ac ("Add AMD IOMMU support into hypervisor")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper@citrix.com>
master commit: bdb30883f3
master date: 2026-05-06 18:56:59 +0200
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>
(cherry picked from commit efcb4c5e2f)
Ocaml's lib directory layout changed in 5.0: the unix and dynlink
libraries have been moved out of the standard library directory into
subdirectories. The compiler still locates them automatically but emits
an ocaml_deprecated_auto_include alert when doing so.
This patch sets the paths explicitly with -I +unix and -I +dynlink to
silence the alert.
Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@vates.tech>
Reviewed-by: Andrii Sultanov <andriy.sultanov@vates.tech>
Tested-by: Andrii Sultanov <andriy.sultanov@vates.tech>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit c3cf7c4121)
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>
(cherry picked from commit 622c9a5ba9)
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>
(cherry picked from commit 161e8f61b5)
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>
(cherry picked from commit 0315d10321)
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>
(cherry picked from commit 36ddaa7918)
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>
(cherry picked from commit d54682a5b2)
The ARM64_WORKAROUND_REPEAT_TLBI workaround is used to mitigate several
errata where broadcast TLBI;DSB sequences don't provide all the
architecturally required synchronization. The workaround performs more
work than necessary, and can have significant overhead. This patch
optimizes the workaround, as explained below.
1. All relevant errata only affect the ordering and/or completion of
memory accesses which have been translated by an invalidated TLB
entry. The actual invalidation of TLB entries is unaffected.
2. The existing workaround is applied to both broadcast and local TLB
invalidation, whereas for all relevant errata it is only necessary to
apply a workaround for broadcast invalidation.
3. The existing workaround replaces every TLBI with a TLBI;DSB;TLBI
sequence, whereas for all relevant errata it is only necessary to
execute a single additional TLBI;DSB sequence after any number of
TLBIs are completed by a DSB.
For example, for a sequence of batched TLBIs:
TLBI <op1>[, <arg1>]
TLBI <op2>[, <arg2>]
TLBI <op3>[, <arg3>]
DSB ISH
... the existing workaround will expand this to:
TLBI <op1>[, <arg1>]
DSB ISH // additional
TLBI <op1>[, <arg1>] // additional
TLBI <op2>[, <arg2>]
DSB ISH // additional
TLBI <op2>[, <arg2>] // additional
TLBI <op3>[, <arg3>]
DSB ISH // additional
TLBI <op3>[, <arg3>] // additional
DSB ISH
... whereas it is sufficient to have:
TLBI <op1>[, <arg1>]
TLBI <op2>[, <arg2>]
TLBI <op3>[, <arg3>]
DSB ISH
TLBI <opX>[, <argX>] // additional
DSB ISH // additional
Using a single additional TLBI and DSB at the end of the sequence can
have significantly lower overhead as each DSB which completes a TLBI
must synchronize with other PEs in the system, with potential
performance effects both locally and system-wide.
4. The existing workaround repeats each specific TLBI operation, whereas
for all relevant errata it is sufficient for the additional TLBI to
use *any* operation which will be broadcast, regardless of which
translation regime or stage of translation the operation applies to.
For example, for a single TLBI:
TLBI ALLE2IS
DSB ISH
... the existing workaround will expand this to:
TLBI ALLE2IS
DSB ISH
TLBI ALLE2IS // additional
DSB ISH // additional
... whereas it is sufficient to have:
TLBI ALLE2IS
DSB ISH
TLBI VALE1IS, XZR // additional
DSB ISH // additional
As the additional TLBI doesn't have to match a specific earlier TLBI,
the additional TLBI can be implemented in separate code, with no
memory of the earlier TLBIs. The additional TLBI can also use a
cheaper TLBI operation.
5. The existing workaround is applied to both Stage-1 and Stage-2 TLB
invalidation, whereas for all relevant errata it is only necessary to
apply a workaround for Stage-1 invalidation.
Architecturally, TLBI operations which invalidate only Stage-2
information (e.g. IPAS2E1IS) are not required to invalidate TLB
entries which combine information from Stage-1 and Stage-2
translation table entries, and consequently may not complete memory
accesses translated by those combined entries. In these cases,
completion of memory accesses is only guaranteed after subsequent
invalidation of Stage-1 information (e.g. VMALLE1IS).
Rework the workaround logic as follows:
- add TLB_HELPER_LOCAL() to be used for local TLB ops without a
workaround,
- modify TLB_HELPER() workaround to use tlbi vale2is, xzr as a second
TLBI,
- drop TLB_HELPER_VA(). It's used only by __flush_xen_tlb_one_local
which is local and does not need workaround and by
__flush_xen_tlb_one. In the latter case, since it's used in a loop,
we don't need a workaround in the middle. Add __tlb_repeat_sync with
a workaround to be used at the end after DSB and before final ISB,
- TLBI VALE2IS passing XZR is used as an additional TLBI. While there is
an identity mapping there, it's used very rarely. The performance
impact is therefore negligible. If things change in the future, we
can revisit the decision.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
(cherry picked from commit 7c502d7591)
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>
(cherry picked from commit 4a93d1fb4f)
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>
(cherry picked from commit eab54f074f)
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>
(cherry picked from commit 471b377747)
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>
(cherry picked from commit d9d2758622)
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>
(cherry picked from commit 3ba374d388)
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>
(cherry picked from commit 83f0e11ed1)
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>
(cherry picked from commit b4a7c17146)
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>
(cherry picked from commit 6b71151cd8)
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>
(cherry picked from commit 9f54e10bf3)
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>
(cherry picked from commit e263eeaf71)
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>
(cherry picked from commit 9ac94138a5)
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>
(cherry picked from commit 5a81fb873c)
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>
(cherry picked from commit 6bb83b1aa0)
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>
(cherry picked from commit 329edc090d)
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>
(cherry picked from commit c9f4586766)
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>
(cherry picked from commit 960713dfd4)
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>
(cherry picked from commit eedff4bcd3)
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>
(cherry picked from commit 5154fdda11)
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>
(cherry picked from commit 784bd4dc0b)
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>
(cherry picked from commit 1dc4d5d818)
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>
(cherry picked from commit 7787f8e939)
When netbooting a unified Xen kernel image (via GRUB chainloader),
the resulting loaded_image->DeviceHandle does not support
SIMPLE_FILE_SYSTEM_PROTOCOL.
Instead of crashing via noreturn PrintErrMesg() in get_parent_handle(),
we defer calling this function until filesystem access is needed.
This way when booting UKI, get_parent_handle() is not called at all.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Szymon Acedański <accek@invisiblethingslab.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
xen/efi: Use blexit() instead of BUG_ON() in read_file()
Follow-up to 880e40b187, which added a BUG_ON() guard in read_file().
But as Jan pointed out, before ExitBootServices BUG_ON()
is not functional. It results in a hang with no message.
On the other hand blexit() prints a message and returns back
to the bootloader.
Fixes: 880e40b187 ("xen/efi: Fix boot from a device without a file system")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Szymon Acedański <accek@invisiblethingslab.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
master commit: 880e40b187
master date: 2026-05-28 16:19:16 +0100
master commit: 7e11543c53
master date: 2026-06-03 08:17:56 +0200
In FRED mode, the SYSCALL instruction does not modify %rcx/%r11. All current
software using SYSCALL expects the pre-FRED behaviour and spills %rcx/%r11
around the invocation, which is why FRED not doing this goes largely
unnoticed.
However, consider the following migration scenario:
* VM suspends. Hypercall, so SYSCALL, %rcx/%r11 left unmodified
* VM moves to a non-FRED system
* Xen resumes the VM with a real SYSRET instruction
Instead of resuming at the instruction following the SYSCALL instruction, the
VM is resumed at whatever dead value was in %rcx.
In FRED mode, manually adjust %rcx/%r11 when SYSCALL is used and when SYSRET
would have been used.
Regarding the choice of instructions in eretu_exit_to_guest(), a branch would
be a context dependent 50/50 split (i.e. increased chance of mispredict), and
only saves one instruction. The CMOVs read the same cacheline that ERETU is
about to process, so are as close to free as we can reasonably get.
Fixes: 76193ef47d ("x86/pv: System call handling in FRED mode")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: c5a4b9125b
master date: 2026-05-28 16:19:16 +0100
__{put,get}_guest() returns -EFAULT on access faults which causes
the injected CR2 to be off by 14 bytes (as EFAULT is 14) which is
incorrect.
Fix the computation by relying on __copy_{from,to}_guest_pv() which
reports the number of remaining bytes instead of a negative errno,
such that we can compute the offset properly.
Fixes: 70ad570b27 ("x86/64: paravirt 32-on-64 call gate support")
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 03878fba4a
master date: 2026-05-22 14:33:44 +0100
Move first read of gt->gt_version inside the critical region of the
rwlock, otherwise concurrent gnttab operations (silly as they would be)
may get mutually confused as to the actual current version.
Fixes: c1488502c949("grant-tables: do not fail attempts to...")
Reported-by: Oleksandr Tyshchenko <Oleksandr_Tyshchenko@epam.com>
Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: c0e548d920
master date: 2026-05-22 13:32:44 +0200
Starting with Zen4, AMD CPUs can virtualise NMIs for a guest. On older
hardware, determining when an NMI is safe to deliver is a challenge and Xen
does not handle all corner cases correctly.
With vNMI, there is an enablement bit and two new bits of state in the VMCB; a
pending bit, and a blocked bit. These directly map to the CPU state for
handling NMIs, and are maintained by hardware during the running of the vCPU.
When vNMI is enabled, have svm_{get,set}_interrupt_shadow() work in terms of
the vnmi_blocking bit rather than the IRET intercept. This allows an emulated
IRET instruction to re-enable NMIs.
When injecting a new NMI, simply set the vnmi_pending bit; hardware will
deliver the NMI to the guest at the next suitable juncture.
One complication is that, when delivering a second NMI before the first has
completed, the mix between common HVM logic and SVM specific logic will try to
open an NMI window, malfunctioning as it does so. When vNMI is enabled, short
circuit this to not consider NMIs blocked.
Signed-off-by: Abdelkareem Abdelsaamad <abdelkareem.abdelsaamad@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 86a203ab8d
master date: 2026-05-21 16:43:01 +0100
PV console doesn't require Xen to be running as a shim and only
requires CONFIG_XEN_GUEST and running as a Xen guest. Update the
documentation accordingly.
Fixes: 4f6609d6a6 ("x86/guest: use PV console for Xen/Dom0 I/O")
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: f47c2e96ab
master date: 2026-05-21 09:13:42 +0200
Introduce the cpuid bit for the SVM vNMI feature support for the x86\AMD
platforms. The feature support is indicated by the CPUID
Fn8000_000A_EDX[25] = 1.
Add defines for the three SVM's Virtual NMI (vNMI) managements bits in the
VMCB structure's vintr_t:
vintr_t(11) - Virtual NMI is pending.
vintr_t(12) - Virtual NMI is masked.
vintr_t(26) - Enable NMI virtualization.
Signed-off-by: Abdelkareem Abdelsaamad <abdelkareem.abdelsaamad@citrix.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
Acked-by: Jan Beulich <jbeulich@suse.com>
master commit: 0294292b4c
master date: 2026-02-23 08:41:32 +0100
libxl_nocpuid.c needs the same treatment as libxl_cpuid.c
Fixes: f6c6f2679d ("libxl: Convert libxl__object_to_json() to json-c")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
(cherry picked from commit ca7906501e)
These do not add any value to the analysis other than duplicating some reports
in whole-program analysis, as the intermediate linking steps are only used to
build the symbol table.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: 79e060ea03
master date: 2026-05-14 13:38:04 +0100
If there are any local symbols in an object file, GNU ld will create an
STT_FILE symbol derived from the object file name if there is none in the
incoming symbol table. The object file name, however, varies between
linking passes. As a result, symbol name compression can yield different
results if any of those local symbols need retaining (Arm [and RISC-V]
mapping symbols are omitted, for example). If that difference in
compression would yield a difference in the sizes of symbol_names[] or
symbols_token_table[], the compare-symbol-tables sanity check will fail.
Fixes: d37d63d4b5 ("symbols: prefix static symbols with their source file names")
Reported-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: c5d554edff
master date: 2026-05-13 10:00:52 +0200
Jan Beulich