Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 165 insertions, 0 deletions

diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
new file mode 100644
index 000000000..118c68da8
--- /dev/null
+++ b/ebpf/ebpf_rss.c
@@ -0,0 +1,165 @@
+/*
+ * eBPF RSS loader
+ *
+ * Developed by Daynix Computing LTD (http://www.daynix.com)
+ *
+ * Authors:
+ *  Andrew Melnychenko <andrew@daynix.com>
+ *  Yuri Benditovich <yuri.benditovich@daynix.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+#include "hw/virtio/virtio-net.h" /* VIRTIO_NET_RSS_MAX_TABLE_LEN */
+
+#include "ebpf/ebpf_rss.h"
+#include "ebpf/rss.bpf.skeleton.h"
+#include "trace.h"
+
+void ebpf_rss_init(struct EBPFRSSContext *ctx)
+{
+    if (ctx != NULL) {
+        ctx->obj = NULL;
+    }
+}
+
+bool ebpf_rss_is_loaded(struct EBPFRSSContext *ctx)
+{
+    return ctx != NULL && ctx->obj != NULL;
+}
+
+bool ebpf_rss_load(struct EBPFRSSContext *ctx)
+{
+    struct rss_bpf *rss_bpf_ctx;
+
+    if (ctx == NULL) {
+        return false;
+    }
+
+    rss_bpf_ctx = rss_bpf__open();
+    if (rss_bpf_ctx == NULL) {
+        trace_ebpf_error("eBPF RSS", "can not open eBPF RSS object");
+        goto error;
+    }
+
+    bpf_program__set_socket_filter(rss_bpf_ctx->progs.tun_rss_steering_prog);
+
+    if (rss_bpf__load(rss_bpf_ctx)) {
+        trace_ebpf_error("eBPF RSS", "can not load RSS program");
+        goto error;
+    }
+
+    ctx->obj = rss_bpf_ctx;
+    ctx->program_fd = bpf_program__fd(
+            rss_bpf_ctx->progs.tun_rss_steering_prog);
+    ctx->map_configuration = bpf_map__fd(
+            rss_bpf_ctx->maps.tap_rss_map_configurations);
+    ctx->map_indirections_table = bpf_map__fd(
+            rss_bpf_ctx->maps.tap_rss_map_indirection_table);
+    ctx->map_toeplitz_key = bpf_map__fd(
+            rss_bpf_ctx->maps.tap_rss_map_toeplitz_key);
+
+    return true;
+error:
+    rss_bpf__destroy(rss_bpf_ctx);
+    ctx->obj = NULL;
+
+    return false;
+}
+
+static bool ebpf_rss_set_config(struct EBPFRSSContext *ctx,
+                                struct EBPFRSSConfig *config)
+{
+    uint32_t map_key = 0;
+
+    if (!ebpf_rss_is_loaded(ctx)) {
+        return false;
+    }
+    if (bpf_map_update_elem(ctx->map_configuration,
+                            &map_key, config, 0) < 0) {
+        return false;
+    }
+    return true;
+}
+
+static bool ebpf_rss_set_indirections_table(struct EBPFRSSContext *ctx,
+                                            uint16_t *indirections_table,
+                                            size_t len)
+{
+    uint32_t i = 0;
+
+    if (!ebpf_rss_is_loaded(ctx) || indirections_table == NULL ||
+       len > VIRTIO_NET_RSS_MAX_TABLE_LEN) {
+        return false;
+    }
+
+    for (; i < len; ++i) {
+        if (bpf_map_update_elem(ctx->map_indirections_table, &i,
+                                indirections_table + i, 0) < 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+static bool ebpf_rss_set_toepliz_key(struct EBPFRSSContext *ctx,
+                                     uint8_t *toeplitz_key)
+{
+    uint32_t map_key = 0;
+
+    /* prepare toeplitz key */
+    uint8_t toe[VIRTIO_NET_RSS_MAX_KEY_SIZE] = {};
+
+    if (!ebpf_rss_is_loaded(ctx) || toeplitz_key == NULL) {
+        return false;
+    }
+    memcpy(toe, toeplitz_key, VIRTIO_NET_RSS_MAX_KEY_SIZE);
+    *(uint32_t *)toe = ntohl(*(uint32_t *)toe);
+
+    if (bpf_map_update_elem(ctx->map_toeplitz_key, &map_key, toe,
+                            0) < 0) {
+        return false;
+    }
+    return true;
+}
+
+bool ebpf_rss_set_all(struct EBPFRSSContext *ctx, struct EBPFRSSConfig *config,
+                      uint16_t *indirections_table, uint8_t *toeplitz_key)
+{
+    if (!ebpf_rss_is_loaded(ctx) || config == NULL ||
+        indirections_table == NULL || toeplitz_key == NULL) {
+        return false;
+    }
+
+    if (!ebpf_rss_set_config(ctx, config)) {
+        return false;
+    }
+
+    if (!ebpf_rss_set_indirections_table(ctx, indirections_table,
+                                      config->indirections_len)) {
+        return false;
+    }
+
+    if (!ebpf_rss_set_toepliz_key(ctx, toeplitz_key)) {
+        return false;
+    }
+
+    return true;
+}
+
+void ebpf_rss_unload(struct EBPFRSSContext *ctx)
+{
+    if (!ebpf_rss_is_loaded(ctx)) {
+        return;
+    }
+
+    rss_bpf__destroy(ctx->obj);
+    ctx->obj = NULL;
+}