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Jinhui Guo e70d5feb10 iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode
[ Upstream commit 42662d1983 ]

PCIe endpoints with ATS enabled and passed through to userspace
(e.g., QEMU, DPDK) can hard-lock the host when their link drops,
either by surprise removal or by a link fault.

Commit 4fc82cd907 ("iommu/vt-d: Don't issue ATS Invalidation
request when device is disconnected") adds pci_dev_is_disconnected()
to devtlb_invalidation_with_pasid() so ATS invalidation is skipped
only when the device is being safely removed, but it applies only
when Intel IOMMU scalable mode is enabled.

With scalable mode disabled or unsupported, a system hard-lock
occurs when a PCIe endpoint's link drops because the Intel IOMMU
waits indefinitely for an ATS invalidation that cannot complete.

Call Trace:
 qi_submit_sync
 qi_flush_dev_iotlb
 __context_flush_dev_iotlb.part.0
 domain_context_clear_one_cb
 pci_for_each_dma_alias
 device_block_translation
 blocking_domain_attach_dev
 iommu_deinit_device
 __iommu_group_remove_device
 iommu_release_device
 iommu_bus_notifier
 blocking_notifier_call_chain
 bus_notify
 device_del
 pci_remove_bus_device
 pci_stop_and_remove_bus_device
 pciehp_unconfigure_device
 pciehp_disable_slot
 pciehp_handle_presence_or_link_change
 pciehp_ist

Commit 81e921fd32 ("iommu/vt-d: Fix NULL domain on device release")
adds intel_pasid_teardown_sm_context() to intel_iommu_release_device(),
which calls qi_flush_dev_iotlb() and can also hard-lock the system
when a PCIe endpoint's link drops.

Call Trace:
 qi_submit_sync
 qi_flush_dev_iotlb
 __context_flush_dev_iotlb.part.0
 intel_context_flush_no_pasid
 device_pasid_table_teardown
 pci_pasid_table_teardown
 pci_for_each_dma_alias
 intel_pasid_teardown_sm_context
 intel_iommu_release_device
 iommu_deinit_device
 __iommu_group_remove_device
 iommu_release_device
 iommu_bus_notifier
 blocking_notifier_call_chain
 bus_notify
 device_del
 pci_remove_bus_device
 pci_stop_and_remove_bus_device
 pciehp_unconfigure_device
 pciehp_disable_slot
 pciehp_handle_presence_or_link_change
 pciehp_ist

Sometimes the endpoint loses connection without a link-down event
(e.g., due to a link fault); killing the process (virsh destroy)
then hard-locks the host.

Call Trace:
 qi_submit_sync
 qi_flush_dev_iotlb
 __context_flush_dev_iotlb.part.0
 domain_context_clear_one_cb
 pci_for_each_dma_alias
 device_block_translation
 blocking_domain_attach_dev
 __iommu_attach_device
 __iommu_device_set_domain
 __iommu_group_set_domain_internal
 iommu_detach_group
 vfio_iommu_type1_detach_group
 vfio_group_detach_container
 vfio_group_fops_release
 __fput

pci_dev_is_disconnected() only covers safe-removal paths;
pci_device_is_present() tests accessibility by reading
vendor/device IDs and internally calls pci_dev_is_disconnected().
On a ConnectX-5 (8 GT/s, x2) this costs ~70 µs.

Since __context_flush_dev_iotlb() is only called on
{attach,release}_dev paths (not hot), add pci_device_is_present()
there to skip inaccessible devices and avoid the hard-lock.

Fixes: 37764b952e ("iommu/vt-d: Global devTLB flush when present context entry changed")
Fixes: 81e921fd32 ("iommu/vt-d: Fix NULL domain on device release")
Cc: stable@vger.kernel.org
Signed-off-by: Jinhui Guo <guojinhui.liam@bytedance.com>
Link: https://lore.kernel.org/r/20251211035946.2071-2-guojinhui.liam@bytedance.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2026-03-12 07:09:29 -04:00
arch x86/uprobes: Fix XOL allocation failure for 32-bit tasks 2026-03-12 07:09:28 -04:00
block block: decouple secure erase size limit from discard size limit 2026-03-04 07:19:38 -05:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: authencesn - reject too-short AAD (assoclen<8) to match ESP/ESN spec 2026-01-30 10:32:12 +01:00
Documentation ipv6: Move ipv6_fl_list from ipv6_pinfo to inet_sock. 2026-03-04 07:20:44 -05:00
drivers iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode 2026-03-12 07:09:29 -04:00
fs ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O 2026-03-12 07:09:28 -04:00
include x86/uprobes: Fix XOL allocation failure for 32-bit tasks 2026-03-12 07:09:28 -04:00
init printk changes for 6.18 2025-10-04 11:13:11 -07:00
io_uring io_uring/zcrx: fix user_ref race between scrub and refill paths 2026-03-04 07:21:33 -05:00
ipc ipc: don't audit capability check in ipc_permissions() 2026-02-26 14:59:19 -08:00
kernel x86/uprobes: Fix XOL allocation failure for 32-bit tasks 2026-03-12 07:09:28 -04:00
lib debugobject: Make it work with deferred page initialization - again 2026-03-12 07:09:08 -04:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm mm: numa_memblks: Identify the accurate NUMA ID of CFMW 2026-03-04 07:21:31 -05:00
net net: qrtr: Drop the MHI auto_queue feature for IPCR DL channels 2026-03-12 07:09:25 -04:00
rust rust: list: Add unsafe blocks for container_of and safety comments 2026-03-04 07:21:35 -05:00
samples samples/ftrace: Adjust LoongArch register restore order in direct calls 2026-01-08 10:17:11 +01:00
scripts kbuild: rpm-pkg: Disable automatic requires for manual debuginfo package 2026-03-04 07:21:32 -05:00
security ima: verify the previous kernel's IMA buffer lies in addressable RAM 2026-03-04 07:21:17 -05:00
sound ASoC: SDCA: Fix comments for sdca_irq_request() 2026-03-12 07:09:21 -04:00
tools selftests/bpf: Fix OOB read in dmabuf_collector 2026-03-12 07:09:21 -04:00
usr gen_init_cpio: Ignore fsync() returning EINVAL on pipes 2025-10-07 09:53:05 -07:00
virt KVM: Don't clobber irqfd routing type when deassigning irqfd 2026-02-11 13:41:44 +01:00
.clang-format memblock: drop for_each_free_mem_pfn_range_in_zone_from() 2025-09-14 08:49:03 +03:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore compile_commands.json globally 2025-08-12 15:53:55 -07:00
.mailmap 8 hotfixes. 4 are cc:stable, 7 are against mm/. 2025-11-26 12:38:05 -08:00
.pylintrc tools: docs: parse-headers.py: move it from sphinx dir 2025-08-29 15:54:42 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: mark ISDN subsystem as orphan 2025-10-27 17:49:45 -07:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS soc: fixes for 6.18, part 4 2025-11-28 09:57:31 -08:00
Makefile Linux 6.18.16 2026-03-04 07:25:12 -05:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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Please read the Documentation/process/changes.rst file, as it contains the
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