hv_netvsc: Wait for completion on request SWITCH_DATA_PATH

The completion indicates if NVSP_MSG4_TYPE_SWITCH_DATA_PATH has been
processed by the VSP. The traffic is steered to VF or synthetic after we
receive this completion.

Signed-off-by: Long Li <longli@microsoft.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 2350342..3a3db2f 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -37,6 +37,10 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
        struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
        struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
 
+       /* Block sending traffic to VF if it's about to be gone */
+       if (!vf)
+               net_device_ctx->data_path_is_vf = vf;
+
        memset(init_pkt, 0, sizeof(struct nvsp_message));
        init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
        if (vf)
@@ -50,8 +54,11 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
 
        vmbus_sendpacket(dev->channel, init_pkt,
                               sizeof(struct nvsp_message),
-                              VMBUS_RQST_ID_NO_RESPONSE,
-                              VM_PKT_DATA_INBAND, 0);
+                              (unsigned long)init_pkt,
+                              VM_PKT_DATA_INBAND,
+                              VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+       wait_for_completion(&nv_dev->channel_init_wait);
+       net_device_ctx->data_path_is_vf = vf;
 }
 
 /* Worker to setup sub channels on initial setup
@@ -754,8 +761,31 @@ static void netvsc_send_completion(struct net_device *ndev,
                                   const struct vmpacket_descriptor *desc,
                                   int budget)
 {
-       const struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
+       const struct nvsp_message *nvsp_packet;
        u32 msglen = hv_pkt_datalen(desc);
+       struct nvsp_message *pkt_rqst;
+       u64 cmd_rqst;
+
+       /* First check if this is a VMBUS completion without data payload */
+       if (!msglen) {
+               cmd_rqst = vmbus_request_addr(&incoming_channel->requestor,
+                                             (u64)desc->trans_id);
+               if (cmd_rqst == VMBUS_RQST_ERROR) {
+                       netdev_err(ndev, "Invalid transaction id\n");
+                       return;
+               }
+
+               pkt_rqst = (struct nvsp_message *)(uintptr_t)cmd_rqst;
+               switch (pkt_rqst->hdr.msg_type) {
+               case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
+                       complete(&net_device->channel_init_wait);
+                       break;
+
+               default:
+                       netdev_err(ndev, "Unexpected VMBUS completion!!\n");
+               }
+               return;
+       }
 
        /* Ensure packet is big enough to read header fields */
        if (msglen < sizeof(struct nvsp_message_header)) {
@@ -763,6 +793,7 @@ static void netvsc_send_completion(struct net_device *ndev,
                return;
        }
 
+       nvsp_packet = hv_pkt_data(desc);
        switch (nvsp_packet->hdr.msg_type) {
        case NVSP_MSG_TYPE_INIT_COMPLETE:
                if (msglen < sizeof(struct nvsp_message_header) +

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 5dd4f37..64ae5f4 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2400,7 +2400,6 @@ static int netvsc_vf_changed(struct net_device *vf_netdev)
 
        if (net_device_ctx->data_path_is_vf == vf_is_up)
                return NOTIFY_OK;
-       net_device_ctx->data_path_is_vf = vf_is_up;
 
        netvsc_switch_datapath(ndev, vf_is_up);
        netdev_info(ndev, "Data path switched %s VF: %s\n",