Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped

From	Joerg Roedel <joro@8bytes.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device gets context mapped
Date	2016-11-30 15:30 +0100
Message-ID	<sJe3v-7fx-17@gated-at.bofh.it> (permalink)
References	(4 earlier) <sIRJD-1es-15@gated-at.bofh.it> <sJ8hr-3E8-1@gated-at.bofh.it> <sJ93Q-49f-3@gated-at.bofh.it> <sJ9Qf-4q9-59@gated-at.bofh.it> <sJajg-4SL-29@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Nov 30, 2016 at 06:23:34PM +0800, Baoquan He wrote:
> OK, talked with Xunlei. The old cache could be entry with present bit
> set.

-EPARSE

Anyway, what I was trying to say is, that the IOMMU TLB is tagged with
domain-ids, and that there is also a context-cache which maps device-ids
to domain-ids.

If we update the context entry then we need to flush only the context
entry, as it will point to a new domain-id then and future IOTLB lookups
in the IOMMU will be using the new domain-id and do not match the old
entries.

	Joerg

Thread

Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Joerg Roedel <joro@8bytes.org> - 2016-11-29 15:40 +0100
  Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Xunlei Pang <xpang@redhat.com> - 2016-11-30 09:20 +0100
    Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Baoquan He <bhe@redhat.com> - 2016-11-30 10:10 +0100
      Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Baoquan He <bhe@redhat.com> - 2016-11-30 11:00 +0100
        Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Baoquan He <bhe@redhat.com> - 2016-11-30 11:30 +0100
          Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Joerg Roedel <joro@8bytes.org> - 2016-11-30 15:30 +0100
            Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Xunlei Pang <xpang@redhat.com> - 2016-12-01 03:20 +0100
              Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Joerg Roedel <joro@8bytes.org> - 2016-12-01 11:40 +0100
                Re: [PATCH] iommu/vt-d: Flush old iotlb for kdump when the device  gets context mapped Xunlei Pang <xpang@redhat.com> - 2016-12-01 13:00 +0100

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