Messages in this thread | | | Subject | Re: [PATCH v2 6/7] iommu/vt-d: Add page request draining support | From | Lu Baolu <> | Date | Thu, 16 Apr 2020 16:38:19 +0800 |
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Hi Kevin,
On 2020/4/15 19:10, Tian, Kevin wrote: > the completion of above sequence ensures that previous queued > page group responses are sent out and received by the endpoint > and vice versa all in-fly page requests from the endpoint are queued > in iommu page request queue. Then comes a problem - you didn't > wait for completion of those newly-queued requests and their > responses.
I thought about this again.
We do page request draining after PASID table entry gets torn down and the devTLB gets invalidated. At this point, if any new page request for this pasid comes in, IOMMU will generate an unrecoverable fault and response the device with IR (Invalid Request). IOMMU won't put this page request into the queue. [VT-d spec 7.4.1]
Hence, we don't need to worry about the newly-queued requests here.
Best regards, baolu
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