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Message-ID: <949dd4db-89ea-4331-5fa7-700f96874ab3@bytedance.com>
Date:   Wed, 17 May 2023 12:58:10 +0800
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Subject: Re: Re: Re: [PATCH v2 0/2] virtio: abstract virtqueue related methods
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To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     stefanha@redhat.com, jasowang@redhat.com,
        xuanzhuo@linux.alibaba.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
References: <20230517025424.601141-1-pizhenwei@bytedance.com>
 <20230516234444-mutt-send-email-mst@kernel.org>
 <8f3ca136-0276-49ca-d703-715c83cff557@bytedance.com>
 <20230516235541-mutt-send-email-mst@kernel.org>
From:   zhenwei pi <pizhenwei@bytedance.com>
In-Reply-To: <20230516235541-mutt-send-email-mst@kernel.org>
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On 5/17/23 11:57, Michael S. Tsirkin wrote:
> On Wed, May 17, 2023 at 11:51:03AM +0800, zhenwei pi wrote:
>>
>>
>> On 5/17/23 11:46, Michael S. Tsirkin wrote:
>>> On Wed, May 17, 2023 at 10:54:22AM +0800, zhenwei pi wrote:
>>>> v1 -> v2:
>>>> - Suggested by MST, use fast path for vring based performance
>>>> sensitive API.
>>>> - Reduce changes in tools/virtio.
>>>>
>>>> Add test result(no obvious change):
>>>> Before:
>>>> time ./vringh_test --parallel
>>>> Using CPUS 0 and 191
>>>> Guest: notified 10036893, pinged 68278
>>>> Host: notified 68278, pinged 3093532
>>>>
>>>> real	0m14.463s
>>>> user	0m6.437s
>>>> sys	0m8.010s
>>>>
>>>> After:
>>>> time ./vringh_test --parallel
>>>> Using CPUS 0 and 191
>>>> Guest: notified 10036709, pinged 68347
>>>> Host: notified 68347, pinged 3085292
>>>>
>>>> real	0m14.196s
>>>> user	0m6.289s
>>>> sys	0m7.885s
>>>>
>>>> v1:
>>>> Hi,
>>>>
>>>> 3 weeks ago, I posted a proposal 'Virtio Over Fabrics':
>>>> https://lists.oasis-open.org/archives/virtio-comment/202304/msg00442.html
>>>>
>>>> Jason and Stefan pointed out that a non-vring based virtqueue has a
>>>> chance to overwrite virtqueue instead of using vring virtqueue.
>>>>
>>>> Then I try to abstract virtqueue related methods in this series, the
>>>> details changes see the comment of patch 'virtio: abstract virtqueue related methods'.
>>>>
>>>> Something is still remained:
>>>> - __virtqueue_break/__virtqueue_unbreak is supposed to use by internal
>>>>     virtio core, I'd like to rename them to vring_virtqueue_break
>>>>     /vring_virtqueue_unbreak. Is this reasonable?
>>>
>>> Why? These just set a flag?
>>>
>>
>> Rename '__virtqueue_break' to 'vring_virtqueue_break', to make symbols
>> exported from virtio_ring.ko have unified prefix 'vring_virtqueue_xxx'.
> 
> I just do not see why you need these callbacks at all.
> 

I use these callbacks for break/unbreak device like:
static inline void virtio_break_device(struct virtio_device *dev)
{
	struct virtqueue *vq;

	spin_lock(&dev->vqs_list_lock);
	list_for_each_entry(vq, &dev->vqs, list) {
		vq->__break(vq);
	}
	spin_unlock(&dev->vqs_list_lock);
}

>>>> - virtqueue_get_desc_addr/virtqueue_get_avail_addr/virtqueue_get_used_addr
>>>>     /virtqueue_get_vring is vring specific, I'd like to rename them like
>>>>     vring_virtqueue_get_desc_addr. Is this reasonable?
>>>> - there are still some functions in virtio_ring.c with prefix *virtqueue*,
>>>>     for example 'virtqueue_add_split', just keep it or rename it to
>>>>     'vring_virtqueue_add_split'?
>>>> zhenwei pi (2):
>>>>     virtio: abstract virtqueue related methods
>>>>     tools/virtio: implement virtqueue in test
>>>>
>>>>    drivers/virtio/virtio_ring.c | 285 +++++-----------------
>>>>    include/linux/virtio.h       | 441 +++++++++++++++++++++++++++++++----
>>>>    include/linux/virtio_ring.h  |  26 +++
>>>>    tools/virtio/linux/virtio.h  | 355 +++++++++++++++++++++++++---
>>>>    4 files changed, 807 insertions(+), 300 deletions(-)
>>>>
>>>> -- 
>>>> 2.20.1
>>>
>>
>> -- 
>> zhenwei pi
> 

-- 
zhenwei pi