84b1cec4fa
LOCKDEP detector reported below warning: ---------------------------------------- [ 23.796949] ======================================================== [ 23.796950] WARNING: possible irq lock inversion dependency detected [ 23.796952] 6.8.0fix+ #811 Not tainted [ 23.796954] -------------------------------------------------------- [ 23.796954] kworker/0:1/8 just changed the state of lock: [ 23.796956] ff365325e084a9b8 (&domain->lock){..-.}-{3:3}, at: amd_iommu_flush_iotlb_all+0x1f/0x50 [ 23.796969] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 23.796970] (pd_bitmap_lock){+.+.}-{3:3} [ 23.796972] and interrupts could create inverse lock ordering between them. [ 23.796973] other info that might help us debug this: [ 23.796974] Chain exists of: &domain->lock --> &dev_data->lock --> pd_bitmap_lock [ 23.796980] Possible interrupt unsafe locking scenario: [ 23.796981] CPU0 CPU1 [ 23.796982] ---- ---- [ 23.796983] lock(pd_bitmap_lock); [ 23.796985] local_irq_disable(); [ 23.796985] lock(&domain->lock); [ 23.796988] lock(&dev_data->lock); [ 23.796990] <Interrupt> [ 23.796991] lock(&domain->lock); Fix this issue by disabling interrupt when acquiring pd_bitmap_lock. Note that this is temporary fix. We have a plan to replace custom bitmap allocator with IDA allocator. Fixes: 87a6f1f22c97 ("iommu/amd: Introduce per-device domain ID to fix potential TLB aliasing issue") Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Vasant Hegde <vasant.hegde@amd.com> Link: https://lore.kernel.org/r/20240404102717.6705-1-vasant.hegde@amd.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.