[Qemu-devel] [PATCH 0/3] exec: further refine address_space_get_iotlb_entry()

[Peter Xu <peterx@redhat.com>]

With the patch applied:

  [PATCH v3] exec: fix address_space_get_iotlb_entry page mask
  (already in Paolo's pull request but not yet merged)

Now we can have valid address masks. However it is still not ideal,
considering that the mask may not be aligned to guest page sizes. One
example would be when huge page is used in guest (please see commit
message in patch 1 for details). It applies to normal pages too. So we
not only need a valid address mask, we should make sure it is page
mask (for x86, it should be either 4K/2M/1G pages).

Patch 1+2 fixes the problem. Tested with both kernel net driver or
testpmd, on either 4K/2M pages, to make sure the page mask is correct.

Patch 3 is cherry picked from PT series, after fixing from 1+2, we'll
definitely want patch 3 now. Here's the simplest TCP streaming test
using vhost dmar and iommu=pt in guest:

  without patch 3:    12.0Gbps
  with patch 3:       33.5Gbps

Please review, thanks.

Peter Xu (3):
  exec: add page_mask for address_space_do_translate
  exec: simplify address_space_get_iotlb_entry
  vhost: iommu: cache static mapping if there is

 exec.c                 | 73 +++++++++++++++++++++++++++++++++-----------------
 hw/virtio/trace-events |  4 +++
 hw/virtio/vhost.c      | 66 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 119 insertions(+), 24 deletions(-)

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2.7.4