Re: [PATCH 0/5] kvm-unittests: add pci PORT IO and MMIO speed tests

[Gleb Natapov <gleb@redhat.com>]

On Wed, Apr 03, 2013 at 11:52:19AM +0300, Michael S. Tsirkin wrote:
> These patches add ability 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 bus scan support instead.  Used together with the
> new pci-testdev backend.  When not present, the new tests are skipped.
> 
> Example 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?
> 
Looks fine to me. Will apply when QEMU part will land in upstream.

> Michael S. Tsirkin (5):
>   kvm-unittest: add printf %c support
>   kvm-unittest: libcflat: add offsetof
>   libcflat.h: define NULL
>   lib: add pci bus scan support
>   vmexit: add pci io and memory speed tests
> 
>  config-x86-common.mak |   1 +
>  lib/libcflat.h        |   3 +
>  lib/printf.c          |   3 +
>  lib/x86/pci.c         |  55 ++++++++++++
>  lib/x86/pci.h         |  16 ++++
>  x86-run               |  13 ++-
>  x86/vmexit.c          | 226 +++++++++++++++++++++++++++++++++++++++++++++++---
>  7 files changed, 302 insertions(+), 15 deletions(-)
>  create mode 100644 lib/x86/pci.c
>  create mode 100644 lib/x86/pci.h
> 
> -- 
> MST

--
			Gleb.