Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Fri, 29 Dec 2023 01:10:05 +0800 | Subject | Re: [RFC PATCH v10 5/5] iommu/vt-d: don't loop for timeout ATS Invalidation request forever | From | Ethan Zhao <> |
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On 12/29/2023 1:05 AM, Ethan Zhao wrote: > When the ATS Invalidation request 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 > > [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
This part get lost perhpas I append "----" here.
Thanks,
Ethan
> > (the left part of exception see the hotplug case of ATS capable device) > > If one endpoint device just no response to the ATS Invalidation request, > but is not gone, it will bring down the whole system, to avoid such > case, don't try the timeout ATS Invalidation request forever. > > Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com> > --- > drivers/iommu/intel/dmar.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c > index 0a8d628a42ee..9edb4b44afca 100644 > --- a/drivers/iommu/intel/dmar.c > +++ b/drivers/iommu/intel/dmar.c > @@ -1453,7 +1453,7 @@ 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)
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