[RFC,3/5] ebpf: Added declaration/initialization routines.

Commit Message

Andrew Melnichenko March 29, 2023, 10:45 a.m. UTC

Now, the binary objects may be retrieved by id/name.
It would require for future qmp commands that may require specific
eBPF blob.

Signed-off-by: Andrew Melnychenko <[e-mail]>
---
 ebpf/ebpf.c      | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 ebpf/ebpf.h      | 25 +++++++++++++++++++++++++
 ebpf/ebpf_rss.c  |  4 ++++
 ebpf/meson.build |  1 +
 4 files changed, 78 insertions(+)
 create mode 100644 ebpf/ebpf.c
 create mode 100644 ebpf/ebpf.h

Patch

diff --git a/ebpf/ebpf.c b/ebpf/ebpf.c
new file mode 100644
index 0000000000..86320d72f5
--- /dev/null
+++ b/ebpf/ebpf.c
@@ -0,0 +1,48 @@ 
+/*
+ * QEMU eBPF binary declaration routine.
+ *
+ * Developed by Daynix Computing LTD (http://www.daynix.com)
+ *
+ * Authors:
+ *  Andrew Melnychenko <[e-mail]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/queue.h"
+#include "ebpf/ebpf.h"
+
+struct ElfBinaryDataEntry {
+    const char *id;
+    const void * (*fn)(size_t *);
+
+    QSLIST_ENTRY(ElfBinaryDataEntry) node;
+};
+
+static QSLIST_HEAD(, ElfBinaryDataEntry) ebpf_elf_obj_list =
+                                            QSLIST_HEAD_INITIALIZER();
+
+void ebpf_register_binary_data(const char *id, const void * (*fn)(size_t *))
+{
+    struct ElfBinaryDataEntry *data = NULL;
+
+    data = g_malloc0(sizeof(*data));
+    data->fn = fn;
+    data->id = id;
+
+    QSLIST_INSERT_HEAD(&ebpf_elf_obj_list, data, node);
+}
+
+const void *ebpf_find_binary_by_id(const char *id, size_t *sz)
+{
+    struct ElfBinaryDataEntry *it = NULL;
+    QSLIST_FOREACH(it, &ebpf_elf_obj_list, node) {
+        if (strcmp(id, it->id) == 0) {
+            return it->fn(sz);
+        }
+    }
+
+    return NULL;
+}
diff --git a/ebpf/ebpf.h b/ebpf/ebpf.h
new file mode 100644
index 0000000000..fd705cb73e
--- /dev/null
+++ b/ebpf/ebpf.h
@@ -0,0 +1,25 @@ 
+/*
+ * QEMU eBPF binary declaration routine.
+ *
+ * Developed by Daynix Computing LTD (http://www.daynix.com)
+ *
+ * Authors:
+ *  Andrew Melnychenko <[e-mail]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#ifndef EBPF_H
+#define EBPF_H
+
+void ebpf_register_binary_data(const char *id, const void * (*fn)(size_t *));
+const void *ebpf_find_binary_by_id(const char *id, size_t *sz);
+
+#define ebpf_binary_init(id, fn)                                           \
+static void __attribute__((constructor)) ebpf_binary_init_ ## fn(void)     \
+{                                                                          \
+    ebpf_register_binary_data(id, fn);                                     \
+}
+
+#endif /* EBPF_H */
diff --git a/ebpf/ebpf_rss.c b/ebpf/ebpf_rss.c
index 08015fecb1..b4038725f2 100644
--- a/ebpf/ebpf_rss.c
+++ b/ebpf/ebpf_rss.c
@@ -21,6 +21,8 @@ 
 
 #include "ebpf/ebpf_rss.h"
 #include "ebpf/rss.bpf.skeleton.h"
+#include "ebpf/ebpf.h"
+
 #include "trace.h"
 
 void ebpf_rss_init(struct EBPFRSSContext *ctx)
@@ -237,3 +239,5 @@  void ebpf_rss_unload(struct EBPFRSSContext *ctx)
     ctx->obj = NULL;
     ctx->program_fd = -1;
 }
+
+ebpf_binary_init("rss", rss_bpf__elf_bytes)
diff --git a/ebpf/meson.build b/ebpf/meson.build
index 2dd0fd8948..67c3f53aa9 100644
--- a/ebpf/meson.build
+++ b/ebpf/meson.build
@@ -1 +1,2 @@ 
+softmmu_ss.add(files('ebpf.c'))
 softmmu_ss.add(when: libbpf, if_true: files('ebpf_rss.c'), if_false: files('ebpf_rss-stub.c'))