[v3,05/20] plugins: Create TCGHelperInfo for all out-of-line callbacks

Commit Message

Richard Henderson April 24, 2024, 11:02 p.m. UTC

TCGHelperInfo includes the ABI for every function call.

Reviewed-by: Pierrick Bouvier <[e-mail]>
Signed-off-by: Richard Henderson <[e-mail]>
---
 include/qemu/plugin.h |  1 +
 plugins/core.c        | 51 ++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 6 deletions(-)

Patch

diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h
index 143262dca8..793c44f1f2 100644
--- a/include/qemu/plugin.h
+++ b/include/qemu/plugin.h
@@ -92,6 +92,7 @@  struct qemu_plugin_dyn_cb {
     union {
         struct {
             union qemu_plugin_cb_sig f;
+            TCGHelperInfo *info;
         } regular;
         struct {
             qemu_plugin_u64 entry;
diff --git a/plugins/core.c b/plugins/core.c
index 837c373690..b0a2e80874 100644
--- a/plugins/core.c
+++ b/plugins/core.c
@@ -338,12 +338,26 @@  void plugin_register_dyn_cb__udata(GArray **arr,
                                    enum qemu_plugin_cb_flags flags,
                                    void *udata)
 {
-    struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
+    static TCGHelperInfo info[3] = {
+        [QEMU_PLUGIN_CB_NO_REGS].flags = TCG_CALL_NO_RWG | TCG_CALL_PLUGIN,
+        [QEMU_PLUGIN_CB_R_REGS].flags = TCG_CALL_NO_WG | TCG_CALL_PLUGIN,
+        [QEMU_PLUGIN_CB_RW_REGS].flags = TCG_CALL_PLUGIN,
+        /*
+         * Match qemu_plugin_vcpu_udata_cb_t:
+         *   void (*)(uint32_t, void *)
+         */
+        [0 ... 2].typemask = (dh_typemask(void, 0) |
+                              dh_typemask(i32, 1) |
+                              dh_typemask(ptr, 2))
+    };
 
+    struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
     dyn_cb->userp = udata;
-    /* Note flags are discarded as unused. */
-    dyn_cb->regular.f.vcpu_udata = cb;
     dyn_cb->type = PLUGIN_CB_REGULAR;
+    dyn_cb->regular.f.vcpu_udata = cb;
+
+    assert((unsigned)flags < ARRAY_SIZE(info));
+    dyn_cb->regular.info = &info[flags];
 }
 
 void plugin_register_vcpu_mem_cb(GArray **arr,
@@ -352,14 +366,39 @@  void plugin_register_vcpu_mem_cb(GArray **arr,
                                  enum qemu_plugin_mem_rw rw,
                                  void *udata)
 {
-    struct qemu_plugin_dyn_cb *dyn_cb;
+    /*
+     * Expect that the underlying type for enum qemu_plugin_meminfo_t
+     * is either int32_t or uint32_t, aka int or unsigned int.
+     */
+    QEMU_BUILD_BUG_ON(
+        !__builtin_types_compatible_p(qemu_plugin_meminfo_t, uint32_t) &&
+        !__builtin_types_compatible_p(qemu_plugin_meminfo_t, int32_t));
 
-    dyn_cb = plugin_get_dyn_cb(arr);
+    static TCGHelperInfo info[3] = {
+        [QEMU_PLUGIN_CB_NO_REGS].flags = TCG_CALL_NO_RWG | TCG_CALL_PLUGIN,
+        [QEMU_PLUGIN_CB_R_REGS].flags = TCG_CALL_NO_WG | TCG_CALL_PLUGIN,
+        [QEMU_PLUGIN_CB_RW_REGS].flags = TCG_CALL_PLUGIN,
+        /*
+         * Match qemu_plugin_vcpu_mem_cb_t:
+         *   void (*)(uint32_t, qemu_plugin_meminfo_t, uint64_t, void *)
+         */
+        [0 ... 2].typemask =
+            (dh_typemask(void, 0) |
+             dh_typemask(i32, 1) |
+             (__builtin_types_compatible_p(qemu_plugin_meminfo_t, uint32_t)
+              ? dh_typemask(i32, 2) : dh_typemask(s32, 2)) |
+             dh_typemask(i64, 3) |
+             dh_typemask(ptr, 4))
+    };
+
+    struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
     dyn_cb->userp = udata;
-    /* Note flags are discarded as unused. */
     dyn_cb->type = PLUGIN_CB_REGULAR;
     dyn_cb->rw = rw;
     dyn_cb->regular.f.vcpu_mem = cb;
+
+    assert((unsigned)flags < ARRAY_SIZE(info));
+    dyn_cb->regular.info = &info[flags];
 }
 
 /*