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Subject: Re: [PATCH V3 6/7] virtio: introduce a mdev based transport
To:     Stefan Hajnoczi <stefanha@gmail.com>
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 <20191014173942.GB5359@stefanha-x1.localdomain>
From:   Jason Wang <jasowang@redhat.com>
Message-ID: <cf8fa583-fb2c-67c3-15d1-64efa8d73121@redhat.com>
Date:   Tue, 15 Oct 2019 11:29:07 +0800
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On 2019/10/15 上午1:39, Stefan Hajnoczi wrote:
> On Fri, Oct 11, 2019 at 04:15:56PM +0800, Jason Wang wrote:
>> +struct virtio_mdev_device {
>> +	struct virtio_device vdev;
>> +	struct mdev_device *mdev;
>> +	unsigned long version;
>> +
>> +	struct virtqueue **vqs;
>> +	/* The lock to protect virtqueue list */
>> +	spinlock_t lock;
>> +	struct list_head virtqueues;
> Is this a list of struct virtio_mdev_vq_info?  Please document the
> actual type in a comment.


Ok.


>> +static int virtio_mdev_find_vqs(struct virtio_device *vdev, unsigned nvqs,
>> +				struct virtqueue *vqs[],
>> +				vq_callback_t *callbacks[],
>> +				const char * const names[],
>> +				const bool *ctx,
>> +				struct irq_affinity *desc)
>> +{
>> +	struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev);
>> +	struct mdev_device *mdev = vm_get_mdev(vdev);
>> +	const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
>> +	struct virtio_mdev_callback cb;
>> +	int i, err, queue_idx = 0;
>> +
>> +	vm_dev->vqs = kmalloc_array(queue_idx, sizeof(*vm_dev->vqs),
>> +				    GFP_KERNEL);
> kmalloc_array(0, ...)?  I would have expected nvqs instead of queue_idx
> (0).
>
> What is this the purpose of vm_dev->vqs and does anything ever access it?


It's useless, will remove it.

Thanks