| Message ID | 20231227030918.536413-6-haifeng.zhao@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | fix vt-d hard lockup when hotplug ATS capable device | expand |
diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c index 76903a8bf963..206ab0b7294f 100644 --- a/drivers/iommu/intel/dmar.c +++ b/drivers/iommu/intel/dmar.c @@ -1457,7 +1457,7 @@ int qi_submit_sync(struct intel_iommu *iommu, struct qi_desc *desc, reclaim_free_desc(qi); raw_spin_unlock_irqrestore(&qi->q_lock, flags); - if (rc == -EAGAIN) + if (rc == -EAGAIN && type !=QI_DIOTLB_TYPE && type != QI_DEIOTLB_TYPE) goto restart; if (iotlb_start_ktime)
When the device-TLB invalidation (ATS invalidation) timeout happens, the qi_submit_sync() will restart and loop for the invalidation request forever till it is done, it will block another invalidation thread such as the fq_timer to issue invalidation request, cause the system lockup as following #11 [fffffe0000b1def0] end_repeat_nmi at ffffffffaa6015f8 [exception RIP: native_queued_spin_lock_slowpath+92] RIP: ffffffffa9d1025c RSP: ffffb202f268cdc8 RFLAGS: 00000002 RAX: 0000000000000101 RBX: ffffffffab36c2a0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffab36c2a0 RBP: ffffffffab36c2a0 R8: 0000000000000001 R9: 0000000000000000 R10: 0000000000000010 R11: 0000000000000018 R12: 0000000000000000 R13: 0000000000000004 R14: ffff9e10d71b1c88 R15: ffff9e10d71b1980 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 --- --- #12 [ffffb202f268cdc8] native_queued_spin_lock_slowpath at ffffffffa9d1025c #13 [ffffb202f268cdc8] do_raw_spin_lock at ffffffffa9d121f1 #14 [ffffb202f268cdd8] _raw_spin_lock_irqsave at ffffffffaa51795b #15 [ffffb202f268cdf8] iommu_flush_dev_iotlb at ffffffffaa20df48 #16 [ffffb202f268ce28] iommu_flush_iova at ffffffffaa20e182 #17 [ffffb202f268ce60] iova_domain_flush at ffffffffaa220e27 #18 [ffffb202f268ce70] fq_flush_timeout at ffffffffaa221c9d #19 [ffffb202f268cea8] call_timer_fn at ffffffffa9d46661 #20 [ffffb202f268cf08] run_timer_softirq at ffffffffa9d47933 #21 [ffffb202f268cf98] __softirqentry_text_start at ffffffffaa8000e0 #22 [ffffb202f268cff0] asm_call_sysvec_on_stack at ffffffffaa60114f --- --- (the left part of exception see the hotplug case of ATS capable device) If one endpoint device just no response to the device-TLB invalidation request, but is not gone, it will bring down the whole system, to avoid such case, don't try the timeout device-TLB request forever. and as synchronous program model of current qi_submit_sync() implementation we couldn't wait for the enough time as PCIe spec said 1min+50%, just break it in current sync model. (PCIe spec r6.1, sec 10.3.1) Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com> --- drivers/iommu/intel/dmar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)