[RFC PATCH 06/12] ebpf/uBPF: Add qemu_ubpf_run_once excute real ebpf program

[Zhang Chen <chen.zhang@intel.com>]

Before running this function, we need to ensure that the
userspace ebpf program has been loaded correctly.

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
---
 ebpf/ubpf-stub.c |  6 ++++++
 ebpf/ubpf.c      | 16 ++++++++++++++++
 ebpf/ubpf.h      |  2 ++
 3 files changed, 24 insertions(+)

diff --git a/ebpf/ubpf-stub.c b/ebpf/ubpf-stub.c
index 885bd954b7..70da421629 100644
--- a/ebpf/ubpf-stub.c
+++ b/ebpf/ubpf-stub.c
@@ -27,3 +27,9 @@ int qemu_ubpf_prepare(UbpfState *u_ebpf, char *code_path)
 {
     return 0;
 }
+
+uint64_t qemu_ubpf_run_once(UbpfState *u_ebpf, void *target,
+                            size_t target_len)
+{
+    return 0;
+}
diff --git a/ebpf/ubpf.c b/ebpf/ubpf.c
index d65fffeda3..8ac513c7ed 100644
--- a/ebpf/ubpf.c
+++ b/ebpf/ubpf.c
@@ -199,3 +199,19 @@ int qemu_ubpf_prepare(UbpfState *u_ebpf, char *code_path)
 
     return 0;
 }
+
+uint64_t qemu_ubpf_run_once(UbpfState *u_ebpf, void *target,
+                            size_t target_len)
+{
+    uint64_t result;
+
+    if (u_ebpf->jit) {
+        result = u_ebpf->fn(target, target_len);
+    } else {
+        if (ubpf_exec(u_ebpf->vm, target, target_len, &result) < 0) {
+            result = UINT64_MAX;
+        }
+    }
+
+    return result;
+}
diff --git a/ebpf/ubpf.h b/ebpf/ubpf.h
index 9a35efbeb6..fc40e84e51 100644
--- a/ebpf/ubpf.h
+++ b/ebpf/ubpf.h
@@ -38,5 +38,7 @@ bool qemu_ubpf_read_code(UbpfState *u_ebpf, char *path);
 bool qemu_ubpf_read_target(UbpfState *u_ebpf, char *path);
 void qemu_ubpf_init_jit(UbpfState *u_ebpf, bool jit);
 int qemu_ubpf_prepare(UbpfState *u_ebpf, char *code_path);
+uint64_t qemu_ubpf_run_once(UbpfState *u_ebpf, void *target,
+                            size_t target_len);
 
 #endif /* QEMU_UBPF_H */
-- 
2.25.1