[Qemu-devel] [PATCH 0/6] virtio: use ioeventfd in TCG and qtest mode

[Stefan Hajnoczi <stefanha@redhat.com>]

This patch series fixes qemu-iotests 068.  Since commit
ea4f3cebc4e0224605ab9dd9724aa4e7768fe372 ("qemu-iotests: 068: test iothread
mode") the test case has attempted to use dataplane without -M accel=kvm.
Although QEMU is capable of running TCG or qtest with emulated ioeventfd/irqfd
we haven't enabled it yet.

Unfortunately the virtio test cases fail when ioeventfd is enabled in qtest
mode.  This is because they make assumptions about virtqueue ISR signalling.
They assume that a request is completed when ISR becomes 1.  However, the ISR
can be set to 1 even though no new request has completed since commit
83d768b5640946b7da55ce8335509df297e2c7cd "virtio: set ISR on dataplane
notifications".

This issue is solved by introducing a proper qvirtqueue_get_buf() API (similar
to the Linux guest drivers) instead of making assumptions about the ISR.  Most
of the patches update the test cases to use the new API.

Stefan Hajnoczi (6):
  libqos: fix typo in virtio.h QVirtQueue->used comment
  libqos: add virtio used ring support
  tests: fix virtio-scsi-test ISR dependence
  tests: fix virtio-blk-test ISR dependence
  tests: fix virtio-net-test ISR dependence
  virtio-pci: use ioeventfd even when KVM is disabled

 tests/libqos/virtio.h    |  8 ++++++-
 hw/virtio/virtio-pci.c   |  2 +-
 tests/libqos/virtio.c    | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
 tests/virtio-blk-test.c  | 27 ++++++++++++++--------
 tests/virtio-net-test.c  |  6 ++---
 tests/virtio-scsi-test.c |  2 +-
 6 files changed, 89 insertions(+), 16 deletions(-)

-- 
2.9.4