[Qemu-devel] [PATCH 0/4] kvm-unittests: add pci PORT IO and MMIO speed tests

[Michael S. Tsirkin]

These patches add a test device, useful to measure speed of MMIO versus PIO, in
different configurations. As I didn't want to reserve a hardcoded range
of memory, I added pci device for this instead.  Used together with the
kvm unittest patches I posted on kvm mailing list.

To use, simply add the device on the pci bus.
Example test output:
        mmio-no-eventfd:pci-mem 8796
        mmio-wildcard-eventfd:pci-mem 3609
        mmio-datamatch-eventfd:pci-mem 3685
        portio-no-eventfd:pci-io 5287
        portio-wildcard-eventfd:pci-io 1762
        portio-datamatch-eventfd:pci-io 1777

First interesting conclusion is that the overhead of MMIO
exit to QEMU as compared to PIO is double that of
MMIO ioeventfd as compared to PIO eventfd. Is this a known fact?

I also had to extend kvm in a minor way, making all ioeventfd
options accessible through the API. This actually needs less code
than checking that users DTRT.

What's the best way to merge this patchset?
I'm guessing the kvm tree ...

Michael S. Tsirkin (4):
  kvm: remove unused APIs
  kvm: support any size for pio eventfd
  kvm: support non datamatch ioeventfd
  pci: add pci test device

 hw/i386/Makefile.objs |   2 +-
 hw/pci-testdev.c      | 306 ++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/pci/pci.h          |   1 +
 include/sysemu/kvm.h  |   4 -
 kvm-all.c             | 133 +++++++++++-----------
 kvm-stub.c            |  10 --
 6 files changed, 376 insertions(+), 80 deletions(-)
 create mode 100644 hw/pci-testdev.c

-- 
MST