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Subject: Re: [PATCH V5 4/6] mdev: introduce virtio device and its device ops
References: <20191023130752.18980-1-jasowang@redhat.com>
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From: Jason Wang <jasowang@redhat.com>
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Date: Tue, 29 Oct 2019 18:42:11 +0800
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To: Zhu Lingshan <lingshan.zhu@linux.intel.com>, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, kwankhede@nvidia.com, alex.williamson@redhat.com, mst@redhat.com, tiwei.bie@intel.com
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On 2019/10/29 =E4=B8=8B=E5=8D=883:42, Zhu Lingshan wrote:
>>
>> +=C2=A0=C2=A0=C2=A0 void (*set_status)(struct mdev_device *mdev, u8 stat=
us);
>
> Hi Jason
>
> Is it possible to make set_status() return an u8 or bool, because this
> may fail in real hardware. Without a returned code, I am not sure=C2=A0
> whether it is a good idea to set the status | NEED_RESET when fail.
>
> Thanks,
> BR
> Zhu Lingshan=20


Hi:


It's possible but I'm not sure whether any user will care about it. E.g
see virtio_add_status():

void virtio_add_status(struct virtio_device *dev, unsigned int status)
{
=C2=A0=C2=A0=C2=A0 might_sleep();
=C2=A0=C2=A0=C2=A0 dev->config->set_status(dev, dev->config->get_status(dev=
) | status);
}
EXPORT_SYMBOL_GPL(virtio_add_status);

And I believe how it work should be:

virtio_add_status(xyz);

status =3D virtio_get_status();

if (!(status & xyz))

=C2=A0=C2=A0=C2=A0 error;

Thanks