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Ethan Zhao 4fc82cd907 iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected
For those endpoint devices connect to system via hotplug capable ports,
users could request a hot reset to the device by flapping device's link
through setting the slot's link control register, as pciehp_ist() DLLSC
interrupt sequence response, pciehp will unload the device driver and
then power it off. thus cause an IOMMU device-TLB invalidation (Intel
VT-d spec, or ATS Invalidation in PCIe spec r6.1) request for non-existence
target device to be sent and deadly loop to retry that request after ITE
fault triggered in interrupt context.

That would cause following continuous hard lockup warning and system hang

[ 4211.433662] pcieport 0000:17:01.0: pciehp: Slot(108): Link Down
[ 4211.433664] pcieport 0000:17:01.0: pciehp: Slot(108): Card not present
[ 4223.822591] NMI watchdog: Watchdog detected hard LOCKUP on cpu 144
[ 4223.822622] CPU: 144 PID: 1422 Comm: irq/57-pciehp Kdump: loaded Tainted: G S
         OE    kernel version xxxx
[ 4223.822623] Hardware name: vendorname xxxx 666-106,
BIOS 01.01.02.03.01 05/15/2023
[ 4223.822623] RIP: 0010:qi_submit_sync+0x2c0/0x490
[ 4223.822624] Code: 48 be 00 00 00 00 00 08 00 00 49 85 74 24 20 0f 95 c1 48 8b
 57 10 83 c1 04 83 3c 1a 03 0f 84 a2 01 00 00 49 8b 04 24 8b 70 34 <40> f6 c6 1
0 74 17 49 8b 04 24 8b 80 80 00 00 00 89 c2 d3 fa 41 39
[ 4223.822624] RSP: 0018:ffffc4f074f0bbb8 EFLAGS: 00000093
[ 4223.822625] RAX: ffffc4f040059000 RBX: 0000000000000014 RCX: 0000000000000005
[ 4223.822625] RDX: ffff9f3841315800 RSI: 0000000000000000 RDI: ffff9f38401a8340
[ 4223.822625] RBP: ffff9f38401a8340 R08: ffffc4f074f0bc00 R09: 0000000000000000
[ 4223.822626] R10: 0000000000000010 R11: 0000000000000018 R12: ffff9f384005e200
[ 4223.822626] R13: 0000000000000004 R14: 0000000000000046 R15: 0000000000000004
[ 4223.822626] FS:  0000000000000000(0000) GS:ffffa237ae400000(0000)
knlGS:0000000000000000
[ 4223.822627] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4223.822627] CR2: 00007ffe86515d80 CR3: 000002fd3000a001 CR4: 0000000000770ee0
[ 4223.822627] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4223.822628] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[ 4223.822628] PKRU: 55555554
[ 4223.822628] Call Trace:
[ 4223.822628]  qi_flush_dev_iotlb+0xb1/0xd0
[ 4223.822628]  __dmar_remove_one_dev_info+0x224/0x250
[ 4223.822629]  dmar_remove_one_dev_info+0x3e/0x50
[ 4223.822629]  intel_iommu_release_device+0x1f/0x30
[ 4223.822629]  iommu_release_device+0x33/0x60
[ 4223.822629]  iommu_bus_notifier+0x7f/0x90
[ 4223.822630]  blocking_notifier_call_chain+0x60/0x90
[ 4223.822630]  device_del+0x2e5/0x420
[ 4223.822630]  pci_remove_bus_device+0x70/0x110
[ 4223.822630]  pciehp_unconfigure_device+0x7c/0x130
[ 4223.822631]  pciehp_disable_slot+0x6b/0x100
[ 4223.822631]  pciehp_handle_presence_or_link_change+0xd8/0x320
[ 4223.822631]  pciehp_ist+0x176/0x180
[ 4223.822631]  ? irq_finalize_oneshot.part.50+0x110/0x110
[ 4223.822632]  irq_thread_fn+0x19/0x50
[ 4223.822632]  irq_thread+0x104/0x190
[ 4223.822632]  ? irq_forced_thread_fn+0x90/0x90
[ 4223.822632]  ? irq_thread_check_affinity+0xe0/0xe0
[ 4223.822633]  kthread+0x114/0x130
[ 4223.822633]  ? __kthread_cancel_work+0x40/0x40
[ 4223.822633]  ret_from_fork+0x1f/0x30
[ 4223.822633] Kernel panic - not syncing: Hard LOCKUP
[ 4223.822634] CPU: 144 PID: 1422 Comm: irq/57-pciehp Kdump: loaded Tainted: G S
         OE     kernel version xxxx
[ 4223.822634] Hardware name: vendorname xxxx 666-106,
BIOS 01.01.02.03.01 05/15/2023
[ 4223.822634] Call Trace:
[ 4223.822634]  <NMI>
[ 4223.822635]  dump_stack+0x6d/0x88
[ 4223.822635]  panic+0x101/0x2d0
[ 4223.822635]  ? ret_from_fork+0x11/0x30
[ 4223.822635]  nmi_panic.cold.14+0xc/0xc
[ 4223.822636]  watchdog_overflow_callback.cold.8+0x6d/0x81
[ 4223.822636]  __perf_event_overflow+0x4f/0xf0
[ 4223.822636]  handle_pmi_common+0x1ef/0x290
[ 4223.822636]  ? __set_pte_vaddr+0x28/0x40
[ 4223.822637]  ? flush_tlb_one_kernel+0xa/0x20
[ 4223.822637]  ? __native_set_fixmap+0x24/0x30
[ 4223.822637]  ? ghes_copy_tofrom_phys+0x70/0x100
[ 4223.822637]  ? __ghes_peek_estatus.isra.16+0x49/0xa0
[ 4223.822637]  intel_pmu_handle_irq+0xba/0x2b0
[ 4223.822638]  perf_event_nmi_handler+0x24/0x40
[ 4223.822638]  nmi_handle+0x4d/0xf0
[ 4223.822638]  default_do_nmi+0x49/0x100
[ 4223.822638]  exc_nmi+0x134/0x180
[ 4223.822639]  end_repeat_nmi+0x16/0x67
[ 4223.822639] RIP: 0010:qi_submit_sync+0x2c0/0x490
[ 4223.822639] Code: 48 be 00 00 00 00 00 08 00 00 49 85 74 24 20 0f 95 c1 48 8b
 57 10 83 c1 04 83 3c 1a 03 0f 84 a2 01 00 00 49 8b 04 24 8b 70 34 <40> f6 c6 10
 74 17 49 8b 04 24 8b 80 80 00 00 00 89 c2 d3 fa 41 39
[ 4223.822640] RSP: 0018:ffffc4f074f0bbb8 EFLAGS: 00000093
[ 4223.822640] RAX: ffffc4f040059000 RBX: 0000000000000014 RCX: 0000000000000005
[ 4223.822640] RDX: ffff9f3841315800 RSI: 0000000000000000 RDI: ffff9f38401a8340
[ 4223.822641] RBP: ffff9f38401a8340 R08: ffffc4f074f0bc00 R09: 0000000000000000
[ 4223.822641] R10: 0000000000000010 R11: 0000000000000018 R12: ffff9f384005e200
[ 4223.822641] R13: 0000000000000004 R14: 0000000000000046 R15: 0000000000000004
[ 4223.822641]  ? qi_submit_sync+0x2c0/0x490
[ 4223.822642]  ? qi_submit_sync+0x2c0/0x490
[ 4223.822642]  </NMI>
[ 4223.822642]  qi_flush_dev_iotlb+0xb1/0xd0
[ 4223.822642]  __dmar_remove_one_dev_info+0x224/0x250
[ 4223.822643]  dmar_remove_one_dev_info+0x3e/0x50
[ 4223.822643]  intel_iommu_release_device+0x1f/0x30
[ 4223.822643]  iommu_release_device+0x33/0x60
[ 4223.822643]  iommu_bus_notifier+0x7f/0x90
[ 4223.822644]  blocking_notifier_call_chain+0x60/0x90
[ 4223.822644]  device_del+0x2e5/0x420
[ 4223.822644]  pci_remove_bus_device+0x70/0x110
[ 4223.822644]  pciehp_unconfigure_device+0x7c/0x130
[ 4223.822644]  pciehp_disable_slot+0x6b/0x100
[ 4223.822645]  pciehp_handle_presence_or_link_change+0xd8/0x320
[ 4223.822645]  pciehp_ist+0x176/0x180
[ 4223.822645]  ? irq_finalize_oneshot.part.50+0x110/0x110
[ 4223.822645]  irq_thread_fn+0x19/0x50
[ 4223.822646]  irq_thread+0x104/0x190
[ 4223.822646]  ? irq_forced_thread_fn+0x90/0x90
[ 4223.822646]  ? irq_thread_check_affinity+0xe0/0xe0
[ 4223.822646]  kthread+0x114/0x130
[ 4223.822647]  ? __kthread_cancel_work+0x40/0x40
[ 4223.822647]  ret_from_fork+0x1f/0x30
[ 4223.822647] Kernel Offset: 0x6400000 from 0xffffffff81000000 (relocation
range: 0xffffffff80000000-0xffffffffbfffffff)

Such issue could be triggered by all kinds of regular surprise removal
hotplug operation. like:

1. pull EP(endpoint device) out directly.
2. turn off EP's power.
3. bring the link down.
etc.

this patch aims to work for regular safe removal and surprise removal
unplug. these hot unplug handling process could be optimized for fix the
ATS Invalidation hang issue by calling pci_dev_is_disconnected() in
function devtlb_invalidation_with_pasid() to check target device state to
avoid sending meaningless ATS Invalidation request to iommu when device is
gone. (see IMPLEMENTATION NOTE in PCIe spec r6.1 section 10.3.1)

For safe removal, device wouldn't be removed until the whole software
handling process is done, it wouldn't trigger the hard lock up issue
caused by too long ATS Invalidation timeout wait. In safe removal path,
device state isn't set to pci_channel_io_perm_failure in
pciehp_unconfigure_device() by checking 'presence' parameter, calling
pci_dev_is_disconnected() in devtlb_invalidation_with_pasid() will return
false there, wouldn't break the function.

For surprise removal, device state is set to pci_channel_io_perm_failure in
pciehp_unconfigure_device(), means device is already gone (disconnected)
call pci_dev_is_disconnected() in devtlb_invalidation_with_pasid() will
return true to break the function not to send ATS Invalidation request to
the disconnected device blindly, thus avoid to trigger further ITE fault,
and ITE fault will block all invalidation request to be handled.
furthermore retry the timeout request could trigger hard lockup.

safe removal (present) & surprise removal (not present)

pciehp_ist()
   pciehp_handle_presence_or_link_change()
     pciehp_disable_slot()
       remove_board()
         pciehp_unconfigure_device(presence) {
           if (!presence)
                pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
           }

this patch works for regular safe removal and surprise removal of ATS
capable endpoint on PCIe switch downstream ports.

Fixes: 6f7db75e1c ("iommu/vt-d: Add second level page table interface")
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Tested-by: Haorong Ye <yehaorong@bytedance.com>
Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com>
Link: https://lore.kernel.org/r/20240301080727.3529832-3-haifeng.zhao@linux.intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-03-06 17:35:55 +01:00
arch IOMMU Fixes for Linux v6.8-rc2 2024-02-02 12:43:51 -08:00
block block: Fix where bio IO priority gets set 2024-02-01 11:00:06 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: scomp - fix req->dst buffer overflow 2023-12-29 11:25:56 +08:00
Documentation iommu/vt-d: Add the document for Intel IOMMU debugfs 2024-03-01 13:51:19 +01:00
drivers iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected 2024-03-06 17:35:55 +01:00
fs Miscellaneous bug fixes and cleanups in ext4's multi-block allocator 2024-02-04 07:33:01 +00:00
include PCI: Make pci_dev_is_disconnected() helper public for other drivers 2024-03-06 17:35:53 +01:00
init Kconfig: Disable -Wstringop-overflow for GCC globally 2024-02-01 14:57:17 -08:00
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mm 22 hotfixes. 11 are cc:stable and the remainder address post-6.7 issues 2024-01-29 17:12:16 -08:00
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scripts Kbuild fixes for v6.8 2024-02-01 11:57:42 -08:00
security lsm/stable-6.8 PR 20240131 2024-02-01 10:00:28 -08:00
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virt Generic: 2024-01-17 13:03:37 -08:00
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.cocciconfig
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.mailmap Char/Misc and other Driver changes for 6.8-rc1 2024-01-17 16:47:17 -08:00
.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: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS update to point people to the new tree for i2c host driver 2024-02-04 06:47:45 +00:00
Makefile Linux 6.8-rc3 2024-02-04 12:20:36 +00:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
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Please read the Documentation/process/changes.rst file, as it contains the
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