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Bug 1693193 - vSMMUv3: Spurious config decoding errors when notifying IOVA invalidations
Summary: vSMMUv3: Spurious config decoding errors when notifying IOVA invalidations
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: qemu-kvm
Version: 8.0
Hardware: aarch64
OS: Linux
Target Milestone: rc
: 8.1
Assignee: Eric Auger
QA Contact: Virtualization Bugs
Depends On:
Blocks: 1677408
TreeView+ depends on / blocked
Reported: 2019-03-27 10:18 UTC by Eric Auger
Modified: 2019-03-28 20:51 UTC (History)
5 users (show)

Fixed In Version:
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Description Eric Auger 2019-03-27 10:18:55 UTC
In some guest PCIe configurations we can observe config decoding errors reported at early stage, such as:

invalid sid=512 (L1STD span=0)

This happens on guest IOVA invalidation forwarding. Those errors should be silenced in that specific case:

The IOVA invalidation is notified to all IOMMU Memory Regions (smmuv3_inv_notifiers_iova/smmuv3_notify_iova), ie. to all PCIe devices protected by the vSMMUv3. In smmuv3_notify_iova we attempt the decode the stream table entry associated to the device (smmuv3_decode_config) and it may happen that the STE is valid. In that case we should just ignore the issue as there is nothing to invalidate. We should be able to discriminate when the decode_config should not fail (in the translation path) and when it is allowed to fail.

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