Feature set negotiation

Closes-bug: #1746578
Fixed the feature negotiation issue by storing
the feature in persistent store and load when
VM comes up.

Change-Id: I3f41079264f040e1b57a146eda7711b171e302ac
(cherry picked from commit 9800537)

dpdk/vr_dpdk_filestore.c

@@ -0,0 +1,100 @@
+/*
+ * vr_dpdk_filestore.c - implements a persistent store
+ * to store/retrieve the VM feature set.
+ *
+ * Copyright (c) 2018 Juniper Networks, Inc. All rights reserved.
+ */
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "vr_dpdk.h"
+#define FEATURE_STORE_PATH "/var/lib/contrail/vm_feature"
+
+int vr_dpdk_store_persist_feature(char *tapdev_name, unsigned long feature_set)
+{
+    char fname[NAME_MAX];
+    struct stat fstat;
+    FILE *fp;
+
+    if (stat(FEATURE_STORE_PATH, &fstat) != 0) {
+        if (mkdir(FEATURE_STORE_PATH, 0755) < 0) {
+            RTE_LOG(ERR, USOCK, "mkdir failed with error %d\n", errno);
+            return -1;
+        }
+    }
+
+    if (snprintf(fname, NAME_MAX, FEATURE_STORE_PATH"/%s", tapdev_name) < 0)
+        return -1;
+
+    RTE_LOG_DP(DEBUG, USOCK, "Write persistent feature %s\n", fname);
+
+    fp = fopen(fname, "w");
+    if (fp == NULL) {
+        return -1;
+    }
+    rewind(fp);
+    fprintf(fp, "%016lx", feature_set);
+    fclose(fp);
+    return 0;
+}
+
+int vr_dpdk_load_persist_feature(char *tapdev_name, unsigned long *feature_set)
+{
+    char fname[NAME_MAX];
+    struct stat fstat;
+    FILE *fp;
+
+    if (stat(FEATURE_STORE_PATH, &fstat) != 0) {
+        if (mkdir(FEATURE_STORE_PATH, 0755) < 0) {
+            RTE_LOG(ERR, USOCK, "mkdir failed with error %d\n", errno);
+            return -1;
+        }
+    }
+
+    if (snprintf(fname, NAME_MAX, FEATURE_STORE_PATH"/%s", tapdev_name) < 0)
+        return -1;
+
+    RTE_LOG_DP(DEBUG, USOCK, "Read persistent feature %s\n", fname);
+
+    if (stat(fname, &fstat) == 0) {
+        fp = fopen(fname, "r");
+        if (fp == NULL) {
+            return -1;
+        }
+        rewind(fp);
+        if(fscanf(fp, "%016lx", feature_set) == EOF) {
+            if (errno) {
+                RTE_LOG(ERR, USOCK, "EOF reached with error %d for tapdev %s\n",
+                        errno, tapdev_name);
+                fclose(fp);
+                return -1;
+            }
+        }
+        RTE_LOG_DP(DEBUG, USOCK, "Feature Set Read %lx for tapdev %s\n",
+                   *feature_set, tapdev_name);
+        fclose(fp);
+        return 0;
+    } else {
+        return -1;
+    }
+}
+
+void vr_dpdk_del_persist_feature(char *tapdev_name)
+{
+    char fname[NAME_MAX];
+    struct stat fstat;
+
+    if (snprintf(fname, NAME_MAX, FEATURE_STORE_PATH"/%s", tapdev_name) < 0)
+        return;
+
+    if (stat(fname, &fstat) == 0) {
+        if(unlink(fname)) {
+            RTE_LOG(ERR, USOCK, "Error deleting file %d for tapdev %s\n",
+                    errno, tapdev_name);
+        }
+    }
+}

dpdk/vr_dpdk_filestore.h

@@ -0,0 +1,15 @@
+/*
+ * vr_dpdk_filestore.h - header for persistent store
+ * to store/retrieve the VM feature set.
+ *
+ * Copyright (c) 2018 Juniper Networks, Inc. All rights reserved.
+ */
+
+#ifndef __VR_DPDK_FILESTORE_H__
+#define __VR_DPDK_FILESTORE_H__
+
+int vr_dpdk_store_persist_feature(char *tapdev_name, unsigned long feature_set);
+int vr_dpdk_load_persist_feature(char *tapdev_name, unsigned long *feature_set);
+void vr_dpdk_del_persist_feature(char *tapdev_name);
+
+#endif /* __VR_DPDK_FILESTORE_H__ */

dpdk/vr_uvhost_msg.c

@@ -13,6 +13,7 @@
 #include "vr_uvhost_client.h"
 #include "vr_uvhost_msg.h"
 #include "vr_uvhost_util.h"
+#include "vr_dpdk_filestore.h"
 
 #include <fcntl.h>
 #include <linux/virtio_net.h>
@@ -355,11 +356,18 @@ vr_uvmh_set_features(vr_uvh_client_t *vru_cl)
 {
     struct vr_interface *vif;
     uint8_t is_gso_vm = 1;
+    unsigned long stored_features = 0;
+
+    if (!vr_dpdk_load_persist_feature(uvhm_client_name(vru_cl),
+                                      &stored_features)) {
+        vru_cl->vruc_msg.u64 |= stored_features;
+    }
+
     vr_uvhost_log("    SET FEATURES: 0x%"PRIx64"\n",
                                             vru_cl->vruc_msg.u64);
 
     vif = __vrouter_get_interface(vrouter_get(0), vru_cl->vruc_idx);
-    is_gso_vm =  (vru_cl->vruc_msg.u64 & (1ULL << VIRTIO_NET_F_GUEST_TSO4)) | 
+    is_gso_vm =  (vru_cl->vruc_msg.u64 & (1ULL << VIRTIO_NET_F_GUEST_TSO4)) |
                  (vru_cl->vruc_msg.u64 & (1ULL << VIRTIO_NET_F_HOST_TSO4))  |
                  (vru_cl->vruc_msg.u64 & (1ULL << VIRTIO_NET_F_GUEST_TSO6)) |
                  (vru_cl->vruc_msg.u64 & (1ULL << VIRTIO_NET_F_HOST_TSO6));
@@ -369,19 +377,21 @@ vr_uvmh_set_features(vr_uvh_client_t *vru_cl)
      */
     if (vif) {
         if (!!is_gso_vm) {
-            vif->vif_flags |= VIF_FLAG_GRO_NEEDED; 
+            vif->vif_flags |= VIF_FLAG_GRO_NEEDED;
         } else {
-            vif->vif_flags &= ~VIF_FLAG_GRO_NEEDED; 
+            vif->vif_flags &= ~VIF_FLAG_GRO_NEEDED;
         }
     }
 
     if (vru_cl->vruc_msg.u64 & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) {
         vif->vif_flags |= VIF_FLAG_MRG_RXBUF;
         vr_dpdk_set_vhost_send_func(vru_cl->vruc_idx, 1);
     } else {
-        vif->vif_flags &= ~VIF_FLAG_MRG_RXBUF; 
+        vif->vif_flags &= ~VIF_FLAG_MRG_RXBUF;
         vr_dpdk_set_vhost_send_func(vru_cl->vruc_idx, 0);
     }
+    vr_dpdk_store_persist_feature(uvhm_client_name(vru_cl),
+                                  vru_cl->vruc_msg.u64);
     return 0;
 }
 
@@ -1228,6 +1238,7 @@ vr_uvh_nl_vif_del_handler(vrnu_vif_del_t *msg)
     }
     /* Unmmap guest memory. */
     uvhm_client_munmap(vru_cl);
+    vr_dpdk_del_persist_feature(uvhm_client_name(vru_cl));
     vr_uvhost_del_client(vru_cl);
 
     return 0;