Messages in this thread | | | Date | Tue, 19 Dec 2023 14:49:39 +0800 | Subject | Re: [PATCH v3 2/2] iommu/vt-d: don's issue devTLB flush request when device is disconnected | From | Ethan Zhao <> |
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On 12/19/2023 2:09 PM, Baolu Lu wrote: > On 2023/12/17 19:49, Ethan Zhao wrote: >> For those endpoint devices connect to system via hotplug capable ports, >> users could request a warm reset to the device by flapping device's link >> through setting the slot's link control register, as pciehpt_ist() DLLSC >> interrupt sequence response, pciehp will unload the device driver and >> then power it off. thus cause an IOMMU devTLB flush request for >> device to >> be sent and a long time completion/timeout waiting 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) >> >> Fix it by checking the device's error_state in >> devtlb_invalidation_with_pasid() to avoid sending meaningless devTLB >> flush >> request to link down device that is set to >> pci_channel_io_perm_failure and >> then powered off in >> >> pciehp_ist() >> pciehp_handle_presence_or_link_change() >> pciehp_disable_slot() >> remove_board() >> pciehp_unconfigure_device() >> >> For SAFE_REMOVAL unplug, link is alive when iommu releases device and >> issues devTLB invalidate request, wouldn't trigger such issue. >> >> This patch works for all kinds of SURPPRISE_REMOVAL unplug operation. >> >> Tested-by: Haorong Ye <yehaorong@bytedance.com> >> Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com> >> --- >> drivers/iommu/intel/pasid.c | 17 +++++++++++++++++ >> 1 file changed, 17 insertions(+) >> >> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c >> index 74e8e4c17e81..182eb5df244d 100644 >> --- a/drivers/iommu/intel/pasid.c >> +++ b/drivers/iommu/intel/pasid.c >> @@ -476,6 +476,23 @@ devtlb_invalidation_with_pasid(struct >> intel_iommu *iommu, >> { >> struct device_domain_info *info; >> u16 sid, qdep, pfsid; >> + struct pci_dev *pdev; >> + >> + pdev = to_pci_dev(dev); >> + if (!pdev) >> + return; >> + >> + /* >> + * If endpoint device's link was brough down by user's pci >> configuration >> + * access to it's hotplug capable slot link control register, as >> sequence >> + * response for DLLSC, pciehp_ist() will set the device >> error_state to >> + * pci_channel_io_perm_failure. Checking device's state here to >> avoid >> + * issuing meaningless devTLB flush request to it, that might >> cause lockup >> + * warning or deadlock because too long time waiting in >> interrupt context. >> + */ >> + >> + if (pci_dev_is_disconnected(pdev)) >> + return; >> info = dev_iommu_priv_get(dev); >> if (!info || !info->ats_enabled) > > It's likely better to check the device status after verifying > ats_enabled. How about below change? > > diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c > index 74e8e4c17e81..fa19c6cdfd8b 100644 > --- a/drivers/iommu/intel/pasid.c > +++ b/drivers/iommu/intel/pasid.c > @@ -481,6 +481,9 @@ devtlb_invalidation_with_pasid(struct intel_iommu > *iommu, > if (!info || !info->ats_enabled) > return; > > + if (pci_dev_is_disconnected(to_pci_dev(dev)))
I like this kind of simplicity, but rationalist always brings me back to the no-error(ugly)
style. :)
Thanks,
Ethan
> + return > + > sid = info->bus << 8 | info->devfn; > qdep = info->ats_qdep; > pfsid = info->pfsid; > > Best regards, > baolu >
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