From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42650) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQHJs-0002Hp-U7 for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQHJr-0003FN-U2 for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:36 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:56678 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fQHJr-0003EO-4z for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:08:35 -0400 From: wexu@redhat.com Date: Tue, 5 Jun 2018 15:08:03 -0400 Message-Id: <1528225683-11413-9-git-send-email-wexu@redhat.com> In-Reply-To: <1528225683-11413-1-git-send-email-wexu@redhat.com> References: <1528225683-11413-1-git-send-email-wexu@redhat.com> Subject: [Qemu-devel] [RFC v2 8/8] virtio: guest driver reload for vhost-net List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: jasowang@redhat.com, tiwei.bie@intel.com, mst@redhat.com, wexu@redhat.com, jfreimann@redhat.com From: Wei Xu last_avail, avail_wrap_count, used_idx and used_wrap_count are needed to support vhost-net backend, all these are either 16 or bool variables, since state.num is 64bit wide, so here it is possible to put them to the 'num' without introducing a new case while handling ioctl. Unload/Reload test has been done successfully with a patch in vhost kernel. Signed-off-by: Wei Xu --- hw/virtio/virtio.c | 42 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 34 insertions(+), 8 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 4543974..153f6d7 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2862,33 +2862,59 @@ hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n) } } -uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) +uint64_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n) { - return vdev->vq[n].last_avail_idx; + uint64_t num; + + num = vdev->vq[n].last_avail_idx; + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { + num |= ((uint64_t)vdev->vq[n].avail_wrap_counter) << 16; + num |= ((uint64_t)vdev->vq[n].used_idx) << 32; + num |= ((uint64_t)vdev->vq[n].used_wrap_counter) << 48; + } + + return num; } -void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) +void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint64_t num) { - vdev->vq[n].last_avail_idx = idx; - vdev->vq[n].shadow_avail_idx = idx; + vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx = (uint16_t)(num); + + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { + vdev->vq[n].avail_wrap_counter = (uint16_t)(num >> 16); + vdev->vq[n].used_idx = (uint16_t)(num >> 32); + vdev->vq[n].used_wrap_counter = (uint16_t)(num >> 48); + } } void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) { rcu_read_lock(); - if (vdev->vq[n].vring.desc) { + if (!vdev->vq[n].vring.desc) { + goto out; + } + + if (!virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); - vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; } + vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; + +out: rcu_read_unlock(); } void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) { rcu_read_lock(); - if (vdev->vq[n].vring.desc) { + if (!vdev->vq[n].vring.desc) { + goto out; + } + + if (!virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]); } + +out: rcu_read_unlock(); } -- 1.8.3.1