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Date:   Tue, 16 May 2023 23:57:04 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     zhenwei pi <pizhenwei@bytedance.com>
Cc:     stefanha@redhat.com, jasowang@redhat.com,
        xuanzhuo@linux.alibaba.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: Re: [PATCH v2 0/2] virtio: abstract virtqueue related methods
Message-ID: <20230516235541-mutt-send-email-mst@kernel.org>
References: <20230517025424.601141-1-pizhenwei@bytedance.com>
 <20230516234444-mutt-send-email-mst@kernel.org>
 <8f3ca136-0276-49ca-d703-715c83cff557@bytedance.com>
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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.

> > > - 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