From: Cornelia Huck <cornelia.huck@de.ibm.com>
To: Greg Kurz <gkurz@linux.vnet.ibm.com>
Cc: Jason Wang <jasowang@redhat.com>,
virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [Qemu-devel] [PATCH RFC 4/7] vhost: set vring endianness for legacy virtio
Date: Tue, 12 May 2015 15:25:30 +0200 [thread overview]
Message-ID: <20150512152530.4ab0c56f.cornelia.huck@de.ibm.com> (raw)
In-Reply-To: <20150506120801.8607.64278.stgit@bahia.huguette.org>
On Wed, 06 May 2015 14:08:02 +0200
Greg Kurz <gkurz@linux.vnet.ibm.com> wrote:
> Legacy virtio is native endian: if the guest and host endianness differ,
> we have to tell vhost so it can swap bytes where appropriate. This is
> done through a vhost ring ioctl.
>
> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
> ---
> hw/virtio/vhost.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 54851b7..1d7b939 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
(...)
> @@ -677,6 +700,16 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
> return -errno;
> }
>
> + if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1) &&
I think this should either go in after the virtio-1 base support (more
feature bits etc.) or get a big fat comment and be touched up later.
I'd prefer the first solution so it does not get forgotten, but I'm not
sure when Michael plans to proceed with the virtio-1 patches (I think
they're mostly fine already).
> + virtio_legacy_is_cross_endian(vdev)) {
> + r = vhost_virtqueue_set_vring_endian_legacy(dev,
> + virtio_is_big_endian(vdev),
> + vhost_vq_index);
> + if (r) {
> + return -errno;
> + }
> + }
> +
> s = l = virtio_queue_get_desc_size(vdev, idx);
> a = virtio_queue_get_desc_addr(vdev, idx);
> vq->desc = cpu_physical_memory_map(a, &l, 0);
next prev parent reply other threads:[~2015-05-12 13:28 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-06 12:07 [Qemu-devel] [PATCH RFC 0/7] vhost: cross-endian support (vhost-net only) Greg Kurz
2015-05-06 12:07 ` [Qemu-devel] [PATCH RFC 1/7] virtio: relax feature check Greg Kurz
2015-05-12 13:14 ` Cornelia Huck
2015-05-12 13:34 ` Michael S. Tsirkin
2015-05-12 13:44 ` Cornelia Huck
2015-05-12 14:46 ` Cornelia Huck
2015-05-12 15:30 ` Michael S. Tsirkin
2015-05-12 16:27 ` Cornelia Huck
2015-05-12 13:49 ` Peter Maydell
2015-05-12 13:55 ` Greg Kurz
2015-05-06 12:07 ` [Qemu-devel] [PATCH RFC 2/7] linux-headers: sync vhost.h Greg Kurz
2015-05-06 12:07 ` [Qemu-devel] [PATCH RFC 3/7] virtio: introduce virtio_legacy_is_cross_endian() Greg Kurz
2015-05-06 12:08 ` [Qemu-devel] [PATCH RFC 4/7] vhost: set vring endianness for legacy virtio Greg Kurz
2015-05-12 13:25 ` Cornelia Huck [this message]
2015-05-12 15:15 ` Michael S. Tsirkin
2015-05-12 16:25 ` Cornelia Huck
2015-05-12 16:40 ` Michael S. Tsirkin
2015-05-13 10:39 ` Cornelia Huck
2015-05-13 11:22 ` Michael S. Tsirkin
2015-05-06 12:08 ` [Qemu-devel] [PATCH RFC 5/7] tap: add VNET_LE/VNET_BE operations Greg Kurz
2015-05-06 12:08 ` [Qemu-devel] [PATCH RFC 6/7] vhost-net: tell tap backend about the vnet endianness Greg Kurz
2015-05-06 12:08 ` [Qemu-devel] [PATCH RFC 7/7] vhost_net: re-enable when cross endian Greg Kurz
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