From: Lu Baolu <baolu.lu@linux.intel.com>
To: "Tian, Kevin" <kevin.tian@intel.com>, Joerg Roedel <joro@8bytes.org>
Cc: "Raj, Ashok" <ashok.raj@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Subject: Re: [PATCH v2 6/7] iommu/vt-d: Add page request draining support
Date: Thu, 16 Apr 2020 16:38:19 +0800 [thread overview]
Message-ID: <acf26559-49d2-653c-156d-3ef383b43879@linux.intel.com> (raw)
In-Reply-To: <AADFC41AFE54684AB9EE6CBC0274A5D19D8209CE@SHSMSX104.ccr.corp.intel.com>
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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next prev parent reply other threads:[~2020-04-16 8:38 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 5:25 [PATCH v2 0/7] iommu/vt-d: Add page request draining support Lu Baolu
2020-04-15 5:25 ` [PATCH v2 1/7] iommu/vt-d: Refactor parameters for qi_submit_sync() Lu Baolu
2020-04-15 8:02 ` Tian, Kevin
2020-04-15 8:33 ` Lu Baolu
2020-04-15 5:25 ` [PATCH v2 2/7] iommu/vt-d: Multiple descriptors per qi_submit_sync() Lu Baolu
2020-04-15 8:18 ` Tian, Kevin
2020-04-15 8:30 ` Lu Baolu
2020-04-15 8:51 ` Tian, Kevin
2020-04-15 5:25 ` [PATCH v2 3/7] iommu/vt-d: debugfs: Add support to show inv queue internals Lu Baolu
2020-04-15 5:25 ` [PATCH v2 4/7] iommu/vt-d: Refactor prq_event_thread() Lu Baolu
2020-04-15 9:15 ` Tian, Kevin
2020-04-16 1:33 ` Lu Baolu
2020-04-15 5:25 ` [PATCH v2 5/7] iommu/vt-d: Save prq descriptors in an internal list Lu Baolu
2020-04-15 9:30 ` Tian, Kevin
2020-04-16 1:46 ` Lu Baolu
2020-04-17 3:25 ` Lu Baolu
2020-04-15 5:25 ` [PATCH v2 6/7] iommu/vt-d: Add page request draining support Lu Baolu
2020-04-15 11:10 ` Tian, Kevin
2020-04-16 2:19 ` Lu Baolu
2020-04-16 8:38 ` Lu Baolu [this message]
2020-04-17 2:27 ` Tian, Kevin
2020-04-15 5:25 ` [PATCH v2 7/7] iommu/vt-d: Remove redundant IOTLB flush Lu Baolu
2020-04-15 7:57 ` [PATCH v2 0/7] iommu/vt-d: Add page request draining support Tian, Kevin
2020-04-15 8:25 ` Lu Baolu
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