[RFC PATCH 07/13] bpf tools: Load ubpf program

[Wang Nan <wangnan0@huawei.com>]

In bpf_program__load(), load ubpf program according to its engine type.

API is improvemented to hold 'struct ubpf_vm *'.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
---
 tools/lib/bpf/libbpf.c | 66 +++++++++++++++++++++++++++++++++++++++-----------
 tools/lib/bpf/libbpf.h | 11 +++++++--
 2 files changed, 61 insertions(+), 16 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3a969fd..e4a1e77 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -81,6 +81,7 @@ static const char *libbpf_strerror_table[NR_ERRNO] = {
 	[ERRCODE_OFFSET(PROG2BIG)]	= "Program too big",
 	[ERRCODE_OFFSET(KVER)]		= "Incorrect kernel version",
 	[ERRCODE_OFFSET(NOUBPF)]	= "UBPF support is not compiled",
+	[ERRCODE_OFFSET(LOADUBPF)]	= "Failed to load user space BPF program",
 };
 
 int libbpf_strerror(int err, char *buf, size_t size)
@@ -949,6 +950,31 @@ static int bpf_object__collect_reloc(struct bpf_object *obj)
 	return 0;
 }
 
+#ifdef HAVE_UBPF_SUPPORT
+static int
+load_ubpf_program(struct bpf_insn *insns, int insns_cnt,
+		  struct ubpf_vm **pvm)
+{
+	struct ubpf_vm *vm = ubpf_create();
+	char *message;
+	int err;
+
+	if (!vm) {
+		pr_warning("Failed to create ubpf vm\n");
+		return -LIBBPF_ERRNO__LOADUBPF;
+	}
+
+	err = ubpf_load(vm, insns, insns_cnt * sizeof(insns[0]), &message);
+	if (err < 0) {
+		pr_warning("Failed to load ubpf program: %s\n", message);
+		return -LIBBPF_ERRNO__LOADUBPF;
+	}
+
+	*pvm = vm;
+	return 0;
+}
+#endif
+
 static int
 load_program(struct bpf_insn *insns, int insns_cnt,
 	     char *license, u32 kern_version, int *pfd)
@@ -1002,11 +1028,12 @@ bpf_program__load(struct bpf_program *prog,
 		  char *license, u32 kern_version)
 {
 	int err = 0, fd, i;
+#ifdef HAVE_UBPF_SUPPORT
+	struct ubpf_vm *vm;
+#endif
 
 	if (prog->engine == ENGINE_UNKNOWN)
 		prog->engine = ENGINE_KBPF;
-	if (prog->engine != ENGINE_KBPF)
-		return -EINVAL;
 
 	if (prog->instances.nr < 0 || !prog->instances.array) {
 		if (prog->preprocessor) {
@@ -1029,10 +1056,15 @@ bpf_program__load(struct bpf_program *prog,
 			pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
 				   prog->section_name, prog->instances.nr);
 		}
-		err = load_program(prog->insns, prog->insns_cnt,
-				   license, kern_version, &fd);
+
+		if_engine(prog,
+			  (err = load_program(prog->insns, prog->insns_cnt,
+					      license, kern_version, &fd)),
+			  (err = load_ubpf_program(prog->insns, prog->insns_cnt,
+						   &vm)));
+
 		if (!err)
-			prog->instan_fd(0) = fd;
+			set_instance(prog, 0, fd, vm);
 		goto out;
 	}
 
@@ -1052,15 +1084,21 @@ bpf_program__load(struct bpf_program *prog,
 		if (!result.new_insn_ptr || !result.new_insn_cnt) {
 			pr_debug("Skip loading the %dth instance of program '%s'\n",
 				 i, prog->section_name);
-			prog->instan_fd(i) = -1;
-			if (result.pfd)
-				*result.pfd = -1;
+
+			if_engine(prog, prog->instan_fd(i) = -1,
+					prog->instan_vm(i) = NULL);
+			if (result.ptr)
+				if_engine(prog, *result.pfd = -1, *result.pvm = NULL);
 			continue;
 		}
 
-		err = load_program(result.new_insn_ptr,
-				   result.new_insn_cnt,
-				   license, kern_version, &fd);
+		if_engine(prog,
+			  (err = load_program(result.new_insn_ptr,
+					      result.new_insn_cnt,
+					      license, kern_version, &fd)),
+			  (err = load_ubpf_program(result.new_insn_ptr,
+						   result.new_insn_cnt,
+						   &vm)));
 
 		if (err) {
 			pr_warning("Loading the %dth instance of program '%s' failed\n",
@@ -1068,9 +1106,9 @@ bpf_program__load(struct bpf_program *prog,
 			goto out;
 		}
 
-		if (result.pfd)
-			*result.pfd = fd;
-		prog->instan_fd(i) = fd;
+		if (result.ptr)
+			if_engine(prog, *result.pfd = fd, *result.pvm = vm);
+		set_instance(prog, i, fd, vm);
 	}
 out:
 	if (err)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f6965ce..8e69c6f 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -27,6 +27,7 @@ enum libbpf_errno {
 	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
 	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
 	LIBBPF_ERRNO__NOUBPF,	/* UBPF support is not compiled */
+	LIBBPF_ERRNO__LOADUBPF,	/* Failed to load user space BPF program */
 	__LIBBPF_ERRNO__END,
 };
 
@@ -123,6 +124,8 @@ struct bpf_insn;
  * bpf_program__nth_fd(prog, 0).
  */
 
+struct ubpf_vm;
+
 struct bpf_prog_prep_result {
 	/*
 	 * If not NULL, load new instruction array.
@@ -131,8 +134,12 @@ struct bpf_prog_prep_result {
 	struct bpf_insn *new_insn_ptr;
 	int new_insn_cnt;
 
-	/* If not NULL, result fd is set to it */
-	int *pfd;
+	/* If not NULL, result is set to it */
+	union {
+		void *ptr;
+		int *pfd;
+		struct ubpf_vm **pvm;
+	};
 };
 
 /*
-- 
1.8.3.4