hyperv: Add support for vNIC hot removal

This patch adds proper handling of the vNIC hot removal event, which includes
a rescind-channel-offer message from the host side that triggers vNIC close and
removal. In this case, the notices to the host during close and removal is not
necessary because the channel is rescinded. This patch blocks these unnecessary
messages, and lets vNIC removal process complete normally.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 10 insertions, 0 deletions

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index a2d1a9612c86..191a6a3ae6ca 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -517,6 +517,8 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
                 /* Just return here, no channel found */
                 return;
 
+        channel->rescind = true;
+
         /* work is initialized for vmbus_process_rescind_offer() from
          * vmbus_process_offer() where the channel got created */
         queue_work(channel->controlwq, &channel->work);
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 6fc834e4306d..dd867e6cabd6 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -764,6 +764,9 @@ int netvsc_send(struct hv_device *device,
                 out_channel = device->channel;
         packet->channel = out_channel;
 
+        if (out_channel->rescind)
+                return -ENODEV;
+
         if (packet->page_buf_cnt) {
                 ret = vmbus_sendpacket_pagebuffer(out_channel,
                                                   packet->page_buf,
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 7b2c5d1e9bad..ec0c40a8f653 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -958,6 +958,9 @@ static int rndis_filter_close_device(struct rndis_device *dev)
                 return 0;
 
         ret = rndis_filter_set_packet_filter(dev, 0);
+        if (ret == -ENODEV)
+                ret = 0;
+
         if (ret == 0)
                 dev->state = RNDIS_DEV_INITIALIZED;
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 08cfaff8a072..476c685ca6f9 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -650,6 +650,8 @@ struct vmbus_channel {
         u8 monitor_grp;
         u8 monitor_bit;
 
+        bool rescind; /* got rescind msg */
+
         u32 ringbuffer_gpadlhandle;
 
         /* Allocated memory for ring buffer */