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authorMaxime Ripard <maxime@cerno.tech>2021-05-11 13:35:52 +0200
committerMaxime Ripard <maxime@cerno.tech>2021-05-11 13:35:52 +0200
commitc55b44c9386f3ee1b08752638559f19deaf6040d (patch)
treec843a21f45180387fcd9eb2625cc9d1f166a3156 /drivers/net/hyperv/netvsc.c
parentMAINTAINERS: Update my e-mail (diff)
parentLinux 5.13-rc1 (diff)
downloadlinux-c55b44c9386f3ee1b08752638559f19deaf6040d.tar.xz
linux-c55b44c9386f3ee1b08752638559f19deaf6040d.zip
Merge drm/drm-fixes into drm-misc-fixes
Start this new release drm-misc-fixes branch Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Diffstat (limited to 'drivers/net/hyperv/netvsc.c')
-rw-r--r--drivers/net/hyperv/netvsc.c55
1 files changed, 51 insertions, 4 deletions
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index c64cc7639c39..9d07c9ce4be2 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -31,12 +31,13 @@
* Switch the data path from the synthetic interface to the VF
* interface.
*/
-void netvsc_switch_datapath(struct net_device *ndev, bool vf)
+int netvsc_switch_datapath(struct net_device *ndev, bool vf)
{
struct net_device_context *net_device_ctx = netdev_priv(ndev);
struct hv_device *dev = net_device_ctx->device_ctx;
struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
+ int ret, retry = 0;
/* Block sending traffic to VF if it's about to be gone */
if (!vf)
@@ -51,15 +52,41 @@ void netvsc_switch_datapath(struct net_device *ndev, bool vf)
init_pkt->msg.v4_msg.active_dp.active_datapath =
NVSP_DATAPATH_SYNTHETIC;
+again:
trace_nvsp_send(ndev, init_pkt);
- vmbus_sendpacket(dev->channel, init_pkt,
+ ret = vmbus_sendpacket(dev->channel, init_pkt,
sizeof(struct nvsp_message),
- (unsigned long)init_pkt,
- VM_PKT_DATA_INBAND,
+ (unsigned long)init_pkt, VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+
+ /* If failed to switch to/from VF, let data_path_is_vf stay false,
+ * so we use synthetic path to send data.
+ */
+ if (ret) {
+ if (ret != -EAGAIN) {
+ netdev_err(ndev,
+ "Unable to send sw datapath msg, err: %d\n",
+ ret);
+ return ret;
+ }
+
+ if (retry++ < RETRY_MAX) {
+ usleep_range(RETRY_US_LO, RETRY_US_HI);
+ goto again;
+ } else {
+ netdev_err(
+ ndev,
+ "Retry failed to send sw datapath msg, err: %d\n",
+ ret);
+ return ret;
+ }
+ }
+
wait_for_completion(&nv_dev->channel_init_wait);
net_device_ctx->data_path_is_vf = vf;
+
+ return 0;
}
/* Worker to setup sub channels on initial setup
@@ -1017,6 +1044,26 @@ static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
}
/* RCU already held by caller */
+/* Batching/bouncing logic is designed to attempt to optimize
+ * performance.
+ *
+ * For small, non-LSO packets we copy the packet to a send buffer
+ * which is pre-registered with the Hyper-V side. This enables the
+ * hypervisor to avoid remapping the aperture to access the packet
+ * descriptor and data.
+ *
+ * If we already started using a buffer and the netdev is transmitting
+ * a burst of packets, keep on copying into the buffer until it is
+ * full or we are done collecting a burst. If there is an existing
+ * buffer with space for the RNDIS descriptor but not the packet, copy
+ * the RNDIS descriptor to the buffer, keeping the packet in place.
+ *
+ * If we do batching and send more than one packet using a single
+ * NetVSC message, free the SKBs of the packets copied, except for the
+ * last packet. This is done to streamline the handling of the case
+ * where the last packet only had the RNDIS descriptor copied to the
+ * send buffer, with the data pointers included in the NetVSC message.
+ */
int netvsc_send(struct net_device *ndev,
struct hv_netvsc_packet *packet,
struct rndis_message *rndis_msg,