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[Qemu-devel] [RFC v2 0/8] packed ring virtio-net userspace backend suppo
From: |
wexu |
Subject: |
[Qemu-devel] [RFC v2 0/8] packed ring virtio-net userspace backend support |
Date: |
Tue, 5 Jun 2018 15:07:55 -0400 |
From: Wei Xu <address@hidden>
Todo:
- address Rx slow performance
- event index interrupt suppression test
v1->v2
- sync to tiwei's v5
- reuse memory cache function with 1.0
- dropped detach patch and notification helper(04 & 05 in v1)
- guest virtio-net driver unload/reload support
- event suppression support(not tested)
- addressed feedback from v1
About guest virtio-net load/unload:
Since last_avail, avail_wrap_count, used_idx and used_wrap_count are
all 16 or bool type variables, so I turned to merge them to
'vhost_vring_state.num' in stead of introducing a new case
in handling ioctl, test has been done with a tweak in kernel side like:
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1439,10 +1439,16 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl,
void __user *argp)
r = -EFAULT;
break;
}
- if (s.num > 0xffff) {
- r = -EINVAL;
- break;
- }
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ vq->avail_wrap_counter = (bool)(uint16_t)(s.num >> 16);
+ vq->last_used_idx = (uint16_t)(s.num >> 32);
+ vq->used_wrap_counter = (bool)(uint16_t)(s.num >> 48);
+ } else {
+ if (s.num > 0xffff) {
+ r = -EINVAL;
+ break;
+ }
+ }
vq->last_avail_idx = s.num;
/* Forget the cached index value. */
vq->avail_idx = vq->last_avail_idx;
@@ -1450,8 +1456,15 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl,
void __user *argp)
case VHOST_GET_VRING_BASE:
s.index = idx;
s.num = vq->last_avail_idx;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
+ s.num |= vq->avail_wrap_counter << 16;
+ s.num |= vq->last_used_idx << 32;
+ s.num |= vq->used_wrap_counter << 48;
+ }
if (copy_to_user(argp, &s, sizeof s))
r = -EFAULT;
+ if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED))
+ s.num |= vq->avail_wrap_counter << 31;
break;
case VHOST_SET_VRING_ADDR:
if (copy_from_user(&a, argp, sizeof a)) {
Wei Xu (8):
virtio: feature bit, data structure, init for packed ring
virtio: memory cache for packed ring
virtio: empty check and desc read for packed ring
virtio: get avail bytes check for packed ring
virtio: queue pop support for packed ring
virtio: flush/push support for packed ring
virtio: event suppression support for packed ring
virtio: support guest driver reload for vhost-net
hw/net/vhost_net.c | 2 +
hw/virtio/virtio.c | 677 +++++++++++++++++++++++--
include/hw/virtio/virtio.h | 4 +-
include/standard-headers/linux/virtio_config.h | 15 +
4 files changed, 649 insertions(+), 49 deletions(-)
--
1.8.3.1
- [Qemu-devel] [RFC v2 0/8] packed ring virtio-net userspace backend support,
wexu <=
- [Qemu-devel] [RFC v2 1/8] virtio: feature bit, data structure, init for 1.1, wexu, 2018/06/05
- [Qemu-devel] [RFC v2 2/8] virtio: memory cache for packed ring, wexu, 2018/06/05
- [Qemu-devel] [RFC v2 3/8] virtio: empty check and desc read for packed ring, wexu, 2018/06/05
- [Qemu-devel] [RFC v2 4/8] virtio: get avail bytes check for packed ring, wexu, 2018/06/05