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

[Paolo Bonzini <pbonzini@redhat.com>]

Il 16/06/2014 11:26, Ming Lei ha scritto:
> On Mon, Jun 16, 2014 at 3:54 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>> Il 09/06/2014 10:00, Ming Lei ha scritto:
>>
>>> On Wed, Jun 4, 2014 at 10:05 AM, Ming Lei <ming.lei@canonical.com> 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>
>>>> ---
>>>>  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
>>
>>
>> Looks good.
>
> Paolo, thanks for your review.
>
>> Can you look into moving DEFINE_VIRTIO_COMMON_FEATURES
>> from all virtio pci devices to TYPE_VIRTIO_PCI, too?
>
> OK, that looks a good cleanup, how about the attached patch?

Since you touched DEFINE_VIRTIO_SCSI_FEATURES and 
DEFINE_VIRTIO_NET_FEATURES, you need to do the same change in 
hw/s390x/s390-virtio-bus.c and hw/s390x/virtio-ccw.c as well. 
Otherwise, the PCI parts of the patch are okay.  Thanks,

Paolo

> If it is OK, I will prepare a formal one for submitting.