plugins: Add enforcement of QEMU_PLUGIN_CB flags in register R/W callbacks

This patch adds functionality to enforce the requested QEMU_PLUGIN_CB_
flags level passed when registering a callback function using the
plugins API. Each time a callback is about to be invoked, a thread-local
variable will be updated with the level that callback requested. Then,
called API functions (in particular, the register read and write API)
will call qemu_plugin_get_cb_flags() to check the level is at least the
level they require.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Rowan Hart <rowanbhart@gmail.com>
Message-ID: <20250624175351.440780-4-rowanbhart@gmail.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-ID: <20250627112512.1880708-8-alex.bennee@linaro.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 33296a1c08..162a56a5da 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -368,6 +368,7 @@ typedef struct CPUNegativeOffsetState {
     GArray *plugin_mem_cbs;
     uint64_t plugin_mem_value_low;
     uint64_t plugin_mem_value_high;
+    int32_t plugin_cb_flags;
 #endif
     IcountDecr icount_decr;
     bool can_do_io;