From: David Hildenbrand <david@redhat.com>
To: Xuan Zhuo <xuanzhuo@linux.alibaba.com>, virtualization@lists.linux.dev
Cc: "Richard Weinberger" <richard@nod.at>,
"Anton Ivanov" <anton.ivanov@cambridgegreys.com>,
"Johannes Berg" <johannes@sipsolutions.net>,
"Hans de Goede" <hdegoede@redhat.com>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
"Vadim Pasternak" <vadimp@nvidia.com>,
"Bjorn Andersson" <andersson@kernel.org>,
"Mathieu Poirier" <mathieu.poirier@linaro.org>,
"Cornelia Huck" <cohuck@redhat.com>,
"Halil Pasic" <pasic@linux.ibm.com>,
"Eric Farman" <farman@linux.ibm.com>,
"Heiko Carstens" <hca@linux.ibm.com>,
"Vasily Gorbik" <gor@linux.ibm.com>,
"Alexander Gordeev" <agordeev@linux.ibm.com>,
"Christian Borntraeger" <borntraeger@linux.ibm.com>,
"Sven Schnelle" <svens@linux.ibm.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Jason Wang" <jasowang@redhat.com>,
linux-um@lists.infradead.org,
platform-driver-x86@vger.kernel.org,
linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org,
kvm@vger.kernel.org
Subject: Re: [PATCH vhost v4 1/6] virtio_balloon: remove the dependence where names[] is null
Date: Fri, 22 Mar 2024 12:56:46 +0100 [thread overview]
Message-ID: <3620be9c-e288-4ff2-a7be-1fcf806e6e6e@redhat.com> (raw)
In-Reply-To: <20240321101532.59272-2-xuanzhuo@linux.alibaba.com>
On 21.03.24 11:15, Xuan Zhuo wrote:
> Currently, the init_vqs function within the virtio_balloon driver relies
> on the condition that certain names array entries are null in order to
> skip the initialization of some virtual queues (vqs). This behavior is
> unique to this part of the codebase. In an upcoming commit, we plan to
> eliminate this dependency by removing the function entirely. Therefore,
> with this change, we are ensuring that the virtio_balloon no longer
> depends on the aforementioned function.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
> drivers/virtio/virtio_balloon.c | 41 +++++++++++++++------------------
> 1 file changed, 19 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 1f5b3dd31fcf..becc12a05407 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -531,49 +531,46 @@ static int init_vqs(struct virtio_balloon *vb)
> struct virtqueue *vqs[VIRTIO_BALLOON_VQ_MAX];
> vq_callback_t *callbacks[VIRTIO_BALLOON_VQ_MAX];
> const char *names[VIRTIO_BALLOON_VQ_MAX];
> - int err;
> + int err, nvqs, idx;
>
> - /*
> - * Inflateq and deflateq are used unconditionally. The names[]
> - * will be NULL if the related feature is not enabled, which will
> - * cause no allocation for the corresponding virtqueue in find_vqs.
> - */
> callbacks[VIRTIO_BALLOON_VQ_INFLATE] = balloon_ack;
> names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate";
> callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack;
> names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
I'd remove the static dependencies here completely and do it
consistently:
nvqs = 0;
callbacks[nvqs] = balloon_ack;
names[nvqs++] = "inflate";
callbacks[nvqs] = balloon_ack;
names[nvqs++] = "deflate";
> - callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL;
> - names[VIRTIO_BALLOON_VQ_STATS] = NULL;
> - callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
> - names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
> - names[VIRTIO_BALLOON_VQ_REPORTING] = NULL;
> +
> + nvqs = VIRTIO_BALLOON_VQ_DEFLATE + 1;
>
> if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
> - names[VIRTIO_BALLOON_VQ_STATS] = "stats";
> - callbacks[VIRTIO_BALLOON_VQ_STATS] = stats_request;
> + names[nvqs] = "stats";
> + callbacks[nvqs] = stats_request;
> + ++nvqs;
callbacks[nvqs++] = stats_request;
If you prefer to keep it separate, "nvqs++" please.
... same here:
idx = 0;
vb->inflate_vq = vqs[idx++];
vb->deflate_vq = vqs[idx++];
...
>
> vb->inflate_vq = vqs[VIRTIO_BALLOON_VQ_INFLATE];
> vb->deflate_vq = vqs[VIRTIO_BALLOON_VQ_DEFLATE];
> +
> + idx = VIRTIO_BALLOON_VQ_DEFLATE + 1;
> +
> if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
> struct scatterlist sg;
> unsigned int num_stats;
> - vb->stats_vq = vqs[VIRTIO_BALLOON_VQ_STATS];
> + vb->stats_vq = vqs[idx++];
>
> /*
> * Prime this virtqueue with one buffer so the hypervisor can
> @@ -593,10 +590,10 @@ static int init_vqs(struct virtio_balloon *vb)
> }
>
> if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
> - vb->free_page_vq = vqs[VIRTIO_BALLOON_VQ_FREE_PAGE];
> + vb->free_page_vq = vqs[idx++];
>
> if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING))
> - vb->reporting_vq = vqs[VIRTIO_BALLOON_VQ_REPORTING];
> + vb->reporting_vq = vqs[idx++];
>
Apart from that LGTM
--
Cheers,
David / dhildenb
next prev parent reply other threads:[~2024-03-22 11:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-21 10:15 [PATCH vhost v4 0/6] refactor the params of find_vqs() Xuan Zhuo
2024-03-21 10:15 ` [PATCH vhost v4 1/6] virtio_balloon: remove the dependence where names[] is null Xuan Zhuo
2024-03-22 11:56 ` David Hildenbrand [this message]
2024-03-25 6:03 ` Xuan Zhuo
2024-03-22 19:16 ` Daniel Verkamp
2024-03-22 21:02 ` David Hildenbrand
2024-03-25 6:08 ` Xuan Zhuo
2024-03-25 9:11 ` David Hildenbrand
2024-03-26 20:23 ` Daniel Verkamp
2024-03-25 9:44 ` Cornelia Huck
2024-03-26 4:11 ` Jason Wang
2024-03-26 4:25 ` Jason Wang
2024-03-21 10:15 ` [PATCH vhost v4 2/6] virtio: remove support for names array entries being null Xuan Zhuo
2024-03-21 10:15 ` [PATCH vhost v4 3/6] virtio: find_vqs: pass struct instead of multi parameters Xuan Zhuo
2024-03-21 10:15 ` [PATCH vhost v4 4/6] virtio: vring_create_virtqueue: " Xuan Zhuo
2024-03-21 10:15 ` [PATCH vhost v4 5/6] virtio: vring_new_virtqueue(): " Xuan Zhuo
2024-03-21 10:15 ` [PATCH vhost v4 6/6] virtio_ring: simplify the parameters of the funcs related to vring_create/new_virtqueue() Xuan Zhuo
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