From: "Michael S. Tsirkin" <mst@redhat.com>
To: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: fam@euphon.net, kwolf@redhat.com, stefanha@redhat.com,
qemu-block@nongnu.org, den@virtuozzo.com, qemu-devel@nongnu.org,
mreitz@redhat.com, ehabkost@redhat.com
Subject: Re: [PATCH v1 2/4] virtio: make seg_max virtqueue size dependent
Date: Tue, 5 Nov 2019 15:51:13 -0500 [thread overview]
Message-ID: <20191105155033-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20191105161105.19016-3-dplotnikov@virtuozzo.com>
On Tue, Nov 05, 2019 at 07:11:03PM +0300, Denis Plotnikov wrote:
> seg_max has a restriction to be less or equal to virtqueue size
> according to Virtio 1.0 specification
>
> Although seg_max can't be set directly, it's worth to express this
> dependancy directly in the code for sanity purpose.
>
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
This is guest visible so needs to be machine type dependent, right?
> ---
> hw/block/virtio-blk.c | 2 +-
> hw/scsi/virtio-scsi.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 06e57a4d39..21530304cf 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -903,7 +903,7 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
> blk_get_geometry(s->blk, &capacity);
> memset(&blkcfg, 0, sizeof(blkcfg));
> virtio_stq_p(vdev, &blkcfg.capacity, capacity);
> - virtio_stl_p(vdev, &blkcfg.seg_max, 128 - 2);
> + virtio_stl_p(vdev, &blkcfg.seg_max, s->conf.queue_size - 2);
> virtio_stw_p(vdev, &blkcfg.geometry.cylinders, conf->cyls);
> virtio_stl_p(vdev, &blkcfg.blk_size, blk_size);
> virtio_stw_p(vdev, &blkcfg.min_io_size, conf->min_io_size / blk_size);
> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> index 839f120256..f7e5533cd5 100644
> --- a/hw/scsi/virtio-scsi.c
> +++ b/hw/scsi/virtio-scsi.c
> @@ -650,7 +650,7 @@ static void virtio_scsi_get_config(VirtIODevice *vdev,
> VirtIOSCSICommon *s = VIRTIO_SCSI_COMMON(vdev);
>
> virtio_stl_p(vdev, &scsiconf->num_queues, s->conf.num_queues);
> - virtio_stl_p(vdev, &scsiconf->seg_max, 128 - 2);
> + virtio_stl_p(vdev, &scsiconf->seg_max, s->conf.virtqueue_size - 2);
> virtio_stl_p(vdev, &scsiconf->max_sectors, s->conf.max_sectors);
> virtio_stl_p(vdev, &scsiconf->cmd_per_lun, s->conf.cmd_per_lun);
> virtio_stl_p(vdev, &scsiconf->event_info_size, sizeof(VirtIOSCSIEvent));
> --
> 2.17.0
next prev parent reply other threads:[~2019-11-05 20:52 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-05 16:11 [PATCH v1 0/4] virtio: fix IO request length in virtio SCSI/block Denis Plotnikov
2019-11-05 16:11 ` [PATCH v1 1/4] virtio: protect non-modern devices from too big virtqueue size setting Denis Plotnikov
2019-11-05 20:56 ` Michael S. Tsirkin
2019-11-06 7:46 ` Denis Plotnikov
2019-11-06 9:01 ` Stefan Hajnoczi
2019-11-06 9:19 ` Stefan Hajnoczi
2019-11-06 11:33 ` Michael S. Tsirkin
2019-11-06 9:18 ` Stefan Hajnoczi
2019-11-06 11:51 ` Michael S. Tsirkin
2019-11-05 16:11 ` [PATCH v1 2/4] virtio: make seg_max virtqueue size dependent Denis Plotnikov
2019-11-05 20:51 ` Michael S. Tsirkin [this message]
2019-11-06 10:07 ` Denis Lunev
2019-11-06 11:54 ` Michael S. Tsirkin
2019-11-08 7:43 ` Denis Plotnikov
2019-11-08 9:52 ` Michael S. Tsirkin
2019-11-05 16:11 ` [PATCH v1 3/4] virtio: increase virtuqueue sizes in new machine types Denis Plotnikov
2019-11-05 20:52 ` Michael S. Tsirkin
2019-11-05 16:11 ` [PATCH v1 4/4] iotests: add test for virtio-scsi and virtio-blk machine type settings Denis Plotnikov
2019-11-06 9:24 ` Stefan Hajnoczi
2019-11-06 10:04 ` Max Reitz
2019-11-06 19:26 ` Eduardo Habkost
2019-11-07 16:30 ` Cleber Rosa
2019-11-08 7:08 ` Denis Plotnikov
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