net/netvsc: handle Rx packets during multi-channel setup

It is possible for a packet to arrive during the configuration
process when setting up multiple queue mode. This would cause
configure to fail; fix by just ignoring receive packets while
waiting for control commands.

Use the receive ring lock to avoid possible races between
oddly behaved applications doing rx_burst and control operations
concurrently.

Fixes: 4e9c73e96e83 ("net/netvsc: add Hyper-V network device")
Cc: stable@dpdk.org
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/drivers/net/netvsc/hn_nvs.c b/drivers/net/netvsc/hn_nvs.c
index 6b51868..477202b 100644 (file)
--- a/drivers/net/netvsc/hn_nvs.c
+++ b/drivers/net/netvsc/hn_nvs.c
@@ -54,7 +54,7 @@ static int hn_nvs_req_send(struct hn_data *hv,
 }
 
 static int
-hn_nvs_execute(struct hn_data *hv,
+__hn_nvs_execute(struct hn_data *hv,
               void *req, uint32_t reqlen,
               void *resp, uint32_t resplen,
               uint32_t type)
@@ -62,6 +62,7 @@ hn_nvs_execute(struct hn_data *hv,
        struct vmbus_channel *chan = hn_primary_chan(hv);
        char buffer[NVS_RESPSIZE_MAX];
        const struct hn_nvs_hdr *hdr;
+       uint64_t xactid;
        uint32_t len;
        int ret;
 
@@ -77,7 +78,7 @@ hn_nvs_execute(struct hn_data *hv,
 
  retry:
        len = sizeof(buffer);
-       ret = rte_vmbus_chan_recv(chan, buffer, &len, NULL);
+       ret = rte_vmbus_chan_recv(chan, buffer, &len, &xactid);
        if (ret == -EAGAIN) {
                rte_delay_us(HN_CHAN_INTERVAL_US);
                goto retry;
@@ -88,7 +89,20 @@ hn_nvs_execute(struct hn_data *hv,
                return ret;
        }
 
+       if (len < sizeof(*hdr)) {
+               PMD_DRV_LOG(ERR, "response missing NVS header");
+               return -EINVAL;
+       }
+
        hdr = (struct hn_nvs_hdr *)buffer;
+
+       /* Silently drop received packets while waiting for response */
+       if (hdr->type == NVS_TYPE_RNDIS) {
+               hn_nvs_ack_rxbuf(chan, xactid);
+               --hv->rxbuf_outstanding;
+               goto retry;
+       }
+
        if (hdr->type != type) {
                PMD_DRV_LOG(ERR, "unexpected NVS resp %#x, expect %#x",
                            hdr->type, type);
@@ -108,6 +122,29 @@ hn_nvs_execute(struct hn_data *hv,
        return 0;
 }
 
+
+/*
+ * Execute one control command and get the response.
+ * Only one command can be active on a channel at once
+ * Unlike BSD, DPDK does not have an interrupt context
+ * so the polling is required to wait for response.
+ */
+static int
+hn_nvs_execute(struct hn_data *hv,
+              void *req, uint32_t reqlen,
+              void *resp, uint32_t resplen,
+              uint32_t type)
+{
+       struct hn_rx_queue *rxq = hv->primary;
+       int ret;
+
+       rte_spinlock_lock(&rxq->ring_lock);
+       ret = __hn_nvs_execute(hv, req, reqlen, resp, resplen, type);
+       rte_spinlock_unlock(&rxq->ring_lock);
+
+       return ret;
+}
+
 static int
 hn_nvs_doinit(struct hn_data *hv, uint32_t nvs_ver)
 {