From 0d92d8a0f0b53c32490ce9623e1a402eb369a7d4 Mon Sep 17 00:00:00 2001
From: Jim Somerville <Jim.Somerville@windriver.com>
Date: Sun, 25 Feb 2018 11:32:54 -0500
Subject: [PATCH] STX: pci-sriov perform limited retry on netlink

We now also perform retries on other netlink errors that previously
would have just done an immediate bailout.

Signed-off-by: Jim Somerville <Jim.Somerville@windriver.com>
[ Trimmed shortlog ]
Signed-off-by: Thales Elero Cervi <thaleselero.cervi@windriver.com>
---
 src/util/virnetdev.c | 100 +++++++++++++++++++++++++++----------------
 1 file changed, 62 insertions(+), 38 deletions(-)

diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
index a73e5f72f..f787b4919 100644
--- a/src/util/virnetdev.c
+++ b/src/util/virnetdev.c
@@ -36,6 +36,7 @@
 # include <sys/ioctl.h>
 #endif
 #include <fcntl.h>
+#include <time.h>
 
 #ifdef __linux__
 # include <linux/sockios.h>
@@ -1533,6 +1534,8 @@ static struct nla_policy ifla_vfstats_policy[IFLA_VF_STATS_MAX+1] = {
     [IFLA_VF_STATS_MULTICAST]   = { .type = NLA_U64 },
 };
 
+#define VIR_NET_DEV_NUM_RETRY 3
+#define VIR_NET_DEV_DELAY_NS  250000000
 
 static int
 virNetDevSetVfConfig(const char *ifname, int vf,
@@ -1540,6 +1543,7 @@ virNetDevSetVfConfig(const char *ifname, int vf,
                      bool *allowRetry)
 {
     int rc = -1;
+    int i;
     char macstr[VIR_MAC_STRING_BUFLEN];
     g_autofree struct nlmsghdr *resp = NULL;
     struct nlmsgerr *err;
@@ -1602,50 +1606,53 @@ virNetDevSetVfConfig(const char *ifname, int vf,
     nla_nest_end(nl_msg, vfinfo);
     nla_nest_end(nl_msg, vfinfolist);
 
-    if (virNetlinkCommand(nl_msg, &resp, &recvbuflen, 0, 0,
-                          NETLINK_ROUTE, 0) < 0)
-        goto cleanup;
-
-    if (recvbuflen < NLMSG_LENGTH(0) || resp == NULL)
-        goto malformed_resp;
+    for (i=0; i<VIR_NET_DEV_NUM_RETRY; i++) {
+        if (virNetlinkCommand(nl_msg, &resp, &recvbuflen, 0, 0,
+                              NETLINK_ROUTE, 0) < 0)
+            goto cleanup;
 
-    switch (resp->nlmsg_type) {
-    case NLMSG_ERROR:
-        err = (struct nlmsgerr *)NLMSG_DATA(resp);
-        if (resp->nlmsg_len < NLMSG_LENGTH(sizeof(*err)))
+        if (recvbuflen < NLMSG_LENGTH(0) || resp == NULL)
             goto malformed_resp;
 
-        /* if allowRetry is true and the error was EINVAL, then
-         * silently return a failure so the caller can retry with a
-         * different MAC address
-         */
-        if (err->error == -EINVAL && *allowRetry &&
-            macaddr && !virMacAddrCmp(macaddr, &zeroMAC)) {
-            goto cleanup;
-        } else if (err->error) {
-            /* other errors are permanent */
-            virReportSystemError(-err->error,
-                                 _("Cannot set interface MAC/vlanid to %s/%d "
-                                   "for ifname %s vf %d"),
-                                 (macaddr
-                                  ? virMacAddrFormat(macaddr, macstr)
-                                  : "(unchanged)"),
-                                 vlanid,
-                                 ifname ? ifname : "(unspecified)",
-                                 vf);
-            *allowRetry = false; /* no use retrying */
-            goto cleanup;
-        }
-        break;
+        switch (resp->nlmsg_type) {
+        case NLMSG_ERROR:
+            err = (struct nlmsgerr *)NLMSG_DATA(resp);
+            if (resp->nlmsg_len < NLMSG_LENGTH(sizeof(*err)))
+                goto malformed_resp;
 
-    case NLMSG_DONE:
-        break;
+            /* if allowRetry is true and the error was EINVAL, then
+             * silently return a failure so the caller can retry with a
+             * different MAC address
+             */
+            if (err->error == -EINVAL && *allowRetry &&
+                macaddr && !virMacAddrCmp(macaddr, &zeroMAC)) {
+                goto cleanup;
+            } else if (err->error) {
+                /* other errors are permanent */
+                virReportSystemError(-err->error,
+                                     _("Cannot set interface MAC/vlanid to %s/%d "
+                                       "for ifname %s vf %d"),
+                                     (macaddr
+                                      ? virMacAddrFormat(macaddr, macstr)
+                                      : "(unchanged)"),
+                                     vlanid,
+                                     ifname ? ifname : "(unspecified)",
+                                     vf);
+                *allowRetry = false; /* no use retrying */
+                /* STX: but we do attempt local retry here within this procedure
+                 * goto cleanup; */
+                goto retry;
+            }
+            break;
 
-    default:
-        goto malformed_resp;
-    }
+        case NLMSG_DONE:
+            break;
+
+        default:
+            goto malformed_resp;
+        }
 
-    rc = 0;
+        rc = 0;
  cleanup:
     VIR_DEBUG("RTM_SETLINK %s vf %d MAC=%s vlanid=%d - %s",
               ifname, vf,
@@ -1664,6 +1671,23 @@ virNetDevSetVfConfig(const char *ifname, int vf,
     virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                    _("allocated netlink buffer is too small"));
     goto cleanup;
+
+ /*STX: local retry logic*/
+ retry:
+    VIR_ERROR(_("Retry: %u"), i);
+    {
+        static struct timespec delay = {
+          .tv_sec = 0,
+          .tv_nsec = VIR_NET_DEV_DELAY_NS };
+
+        if (nanosleep(&delay, NULL) < 0) {
+            virReportSystemError(errno, "%s", _("Failed to sleep"));
+            goto cleanup;
+        }
+    }
+
+    } /* End of local retry loop */
+    goto cleanup; /* we exhausted our local retries */
 }
 
 /**
-- 
2.25.1