Re: [Qemu-devel] [PATCH] hw/virtio: enable common virtio feature for mmio device

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jun 04, 2014 at 10:05:55AM +0800, Ming Lei wrote:
> Both 'indirect_desc' and 'event_idx' are bus independent features,
> and they should be enabled for mmio devices too.
> 
> On arm64 quad core VM(qemu-kvm), the patch can increase block I/O
> performance a lot with latest linux tree:
>         - without the patch: 14K IOPS
>         - with the patch: 34K IOPS
>     
> fio script:
>         [global]
>         direct=1
>         bsrange=4k-4k
>         timeout=10
>         numjobs=4
>         ioengine=libaio
>         iodepth=64
>     
>         filename=/dev/vdc
>         group_reporting=1
>     
>         [f1]
>         rw=randread
> 
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Ming Lei <ming.lei@canonical.com>

Applied, thanks!
I'm guessing this doesn't affect cross-version
migration since virtio-mmio isn't used on
a PC and that's the only versioned machine.

> ---
>  hw/virtio/virtio-mmio.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
> index 8829eb0..18c6e5b 100644
> --- a/hw/virtio/virtio-mmio.c
> +++ b/hw/virtio/virtio-mmio.c
> @@ -369,10 +369,16 @@ static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
>      sysbus_init_mmio(sbd, &proxy->iomem);
>  }
>  
> +static Property virtio_mmio_properties[] = {
> +    DEFINE_VIRTIO_COMMON_FEATURES(VirtIOMMIOProxy, host_features),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static void virtio_mmio_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>  
> +    dc->props = virtio_mmio_properties;
>      dc->realize = virtio_mmio_realizefn;
>      dc->reset = virtio_mmio_reset;
>      set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> -- 
> 1.7.9.5
>