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548183ea38
Set the posted MSI irq_chip's irq_ack() hook to irq_move_irq() instead of
a dummy/empty callback so that posted MSIs process pending changes to the
IRQ's SMP affinity. Failure to honor a pending set-affinity results in
userspace being unable to change the effective affinity of the IRQ, as
IRQD_SETAFFINITY_PENDING is never cleared and so irq_set_affinity_locked()
always defers moving the IRQ.
The issue is most easily reproducible by setting /proc/irq/xx/smp_affinity
multiple times in quick succession, as only the first update is likely to
be handled in process context.
Fixes: ed1e48ea43 ("iommu/vt-d: Enable posted mode for device MSIs")
Cc: Robert Lippert <rlippert@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Wentao Yang <wentaoyang@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20250321194249.1217961-1-seanjc@google.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.