[RFC 3/3] vdpasim_net: control virtqueue support

Longpeng(Mike)
2022-01-17T09:29:43Z

Introduces the control virtqueue support for vdpasim_net, based on
Jason's RFC [1].

[1] https://patchwork.kernel.org/project/kvm/patch/20200924032125.18619-25-jasowang@redhat.com/

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
drivers/vdpa/vdpa_sim/vdpa_sim_net.c | 83 +++++++++++++++++++++++++++-
1 file changed, 81 insertions(+), 2 deletions(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
index 76dd24abc791..e9e388fd3cff 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
@@ -26,9 +26,85 @@
#define DRV_LICENSE "GPL v2"

#define VDPASIM_NET_FEATURES (VDPASIM_FEATURES | \
- (1ULL << VIRTIO_NET_F_MAC))
+ (1ULL << VIRTIO_NET_F_MAC) | \
+ (1ULL << VIRTIO_NET_F_CTRL_VQ) | \
+ (1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR))

-#define VDPASIM_NET_VQ_NUM 2
+#define VDPASIM_NET_VQ_NUM 3
+
+virtio_net_ctrl_ack vdpasim_net_handle_ctrl_mac(struct vdpasim *vdpasim,
+ u8 cmd)
+{
+ struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
+ virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+ struct virtio_net_config *config = vdpasim->config;
+ size_t read;
+
+ switch (cmd) {
+ case VIRTIO_NET_CTRL_MAC_ADDR_SET:
+ read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->out_iov,
+ (void *)config->mac, ETH_ALEN);
+ if (read == ETH_ALEN)
+ status = VIRTIO_NET_OK;
+ break;
+ default:
+ break;
+ }
+
+ return status;
+}
+
+static void vdpasim_net_handle_cvq(struct vdpasim *vdpasim)
+{
+ struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
+ virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+ struct virtio_net_ctrl_hdr ctrl;
+ size_t read, write;
+ int err;
+
+ if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ)))
+ return;
+
+ if (!cvq->ready)
+ return;
+
+ while (true) {
+ err = vringh_getdesc_iotlb(&cvq->vring, &cvq->out_iov, &cvq->in_iov,
+ &cvq->head, GFP_ATOMIC);
+ if (err <= 0)
+ break;
+
+ read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
+ sizeof(ctrl));
+ if (read != sizeof(ctrl))
+ break;
+
+ switch (ctrl.class) {
+ case VIRTIO_NET_CTRL_MAC:
+ status = vdpasim_net_handle_ctrl_mac(vdpasim, ctrl.cmd);
+ break;
+ default:
+ break;
+ }
+
+ /* Make sure data is wrote before advancing index */
+ smp_wmb();
+
+ write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov,
+ &status, sizeof (status));
+ vringh_complete_iotlb(&cvq->vring, cvq->head, write);
+ vringh_kiov_cleanup(&cvq->in_iov);
+ vringh_kiov_cleanup(&cvq->out_iov);
+
+ /* Make sure used is visible before rasing the interrupt. */
+ smp_wmb();
+
+ local_bh_disable();
+ if (vringh_need_notify_iotlb(&cvq->vring) > 0)
+ vringh_notify(&cvq->vring);
+ local_bh_enable();
+ }
+}

static void vdpasim_net_work(struct work_struct *work)
{
@@ -42,6 +118,9 @@ static void vdpasim_net_work(struct work_struct *work)

spin_lock(&vdpasim->lock);

+ /* process ctrl vq first */
+ vdpasim_net_handle_cvq(vdpasim);
+
if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto out;

--
2.23.0