diff mbox series

[v3,2/2] iommu/vt-d: don's issue devTLB flush request when device is disconnected

Message ID 20231217114902.3836260-3-haifeng.zhao@linux.intel.com (mailing list archive)
State Superseded
Headers show
Series fix vt-d hard lockup when hotplug ATS capable device | expand

Commit Message

Ethan Zhao Dec. 17, 2023, 11:49 a.m. UTC
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(+)

Comments

Baolu Lu Dec. 19, 2023, 6:09 a.m. UTC | #1
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)))
+               return
+
         sid = info->bus << 8 | info->devfn;
         qdep = info->ats_qdep;
         pfsid = info->pfsid;

Best regards,
baolu
Ethan Zhao Dec. 19, 2023, 6:37 a.m. UTC | #2
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)))
> +               return
> +

I did this in the first version, but I thought seconds, changed it.

Anyway, not performance critical path, I am okay with them.


Thanks,

Ethan

> sid = info->bus << 8 | info->devfn;
>         qdep = info->ats_qdep;
>         pfsid = info->pfsid;
>
> Best regards,
> baolu
Ethan Zhao Dec. 19, 2023, 6:49 a.m. UTC | #3
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
>
Baolu Lu Dec. 19, 2023, 6:57 a.m. UTC | #4
On 2023/12/19 14:49, Ethan Zhao wrote:
>>> 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.  
Ethan Zhao Dec. 19, 2023, 7:16 a.m. UTC | #5
On 12/19/2023 2:57 PM, Baolu Lu wrote:
> On 2023/12/19 14:49, Ethan Zhao wrote:
>>>> 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.  
Ethan Zhao Dec. 19, 2023, 7:27 a.m. UTC | #6
Baolu,

On 12/19/2023 3:16 PM, Ethan Zhao wrote:
>
> On 12/19/2023 2:57 PM, Baolu Lu wrote:
>> On 2023/12/19 14:49, Ethan Zhao wrote:
>>>>> 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.  
Baolu Lu Dec. 19, 2023, 7:35 a.m. UTC | #7
On 2023/12/19 15:27, Ethan Zhao wrote:
> Baolu,
> 
> On 12/19/2023 3:16 PM, Ethan Zhao wrote:
>>
>> On 12/19/2023 2:57 PM, Baolu Lu wrote:
>>> On 2023/12/19 14:49, Ethan Zhao wrote:
>>>>>> 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.  
Ethan Zhao Dec. 19, 2023, 7:44 a.m. UTC | #8
On 12/19/2023 3:35 PM, Baolu Lu wrote:
> On 2023/12/19 15:27, Ethan Zhao wrote:
>> Baolu,
>>
>> On 12/19/2023 3:16 PM, Ethan Zhao wrote:
>>>
>>> On 12/19/2023 2:57 PM, Baolu Lu wrote:
>>>> On 2023/12/19 14:49, Ethan Zhao wrote:
>>>>>>> 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.  
diff mbox series

Patch

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)