Some registers should be marked as read-only from a plugin API
perspective, as writing to them via qemu_plugin_write_register has no
effect. This includes the program counter, and we expose this fact to
the plugins with this patch.

Signed-off-by: Florian Hofhammer <[email protected]>
---
 include/plugins/qemu-plugin.h |  2 ++
 plugins/api.c                 | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/include/plugins/qemu-plugin.h b/include/plugins/qemu-plugin.h
index 04c884e82b..ae711758f1 100644
--- a/include/plugins/qemu-plugin.h
+++ b/include/plugins/qemu-plugin.h
@@ -979,11 +979,13 @@ struct qemu_plugin_register;
  *          writing value with qemu_plugin_write_register
  * @name: register name
  * @feature: optional feature descriptor, can be NULL
+ * @is_readonly: true if the register cannot be written via 
qemu_plugin_write_register
  */
 typedef struct {
     struct qemu_plugin_register *handle;
     const char *name;
     const char *feature;
+    bool is_readonly;
 } qemu_plugin_reg_descriptor;
 
 /**
diff --git a/plugins/api.c b/plugins/api.c
index ca3e93a194..b2c52d2a09 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -410,6 +410,12 @@ bool qemu_plugin_bool_parse(const char *name, const char 
*value, bool *ret)
  * ancillary data the plugin might find useful.
  */
 
+static const char pc_str[] = "pc"; // generic name for program counter
+static const char eip_str[] = "eip"; // x86 specific name for program counter
+static const char rip_str[] = "rip"; // x86_64 specific name for program 
counter
+static const char pswa_str[] = "pswa"; // s390x specific name for program 
counter
+static const char iaoq_str[] = "iaoq"; // HP/PA specific name for program 
counter
+static const char rpc_str[] = "rpc"; // microblaze specific name for program 
counter
 static GArray *create_register_handles(GArray *gdbstub_regs)
 {
     GArray *find_data = g_array_new(true, true,
@@ -427,6 +433,16 @@ static GArray *create_register_handles(GArray 
*gdbstub_regs)
         /* Create a record for the plugin */
         desc.handle = GINT_TO_POINTER(grd->gdb_reg + 1);
         desc.name = g_intern_string(grd->name);
+        desc.is_readonly = false;
+        if (g_strcmp0(desc.name, pc_str) == 0
+            || g_strcmp0(desc.name, eip_str) == 0
+            || g_strcmp0(desc.name, rip_str) == 0
+            || g_strcmp0(desc.name, pswa_str) == 0
+            || g_strcmp0(desc.name, iaoq_str) == 0
+            || g_strcmp0(desc.name, rpc_str) == 0
+           ) {
+            desc.is_readonly = true;
+        }
         desc.feature = g_intern_string(grd->feature_name);
         g_array_append_val(find_data, desc);
     }
-- 
2.53.0

Reply via email to