diff options
| -rw-r--r-- | include/qemu/qemu-plugin.h | 50 | ||||
| -rw-r--r-- | plugins/api.c | 55 | ||||
| -rw-r--r-- | plugins/qemu-plugins.symbols | 2 |
3 files changed, 105 insertions, 2 deletions
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h index 93981f8f89..45e2ebc8f8 100644 --- a/include/qemu/qemu-plugin.h +++ b/include/qemu/qemu-plugin.h @@ -11,6 +11,7 @@ #ifndef QEMU_QEMU_PLUGIN_H #define QEMU_QEMU_PLUGIN_H +#include <glib.h> #include <inttypes.h> #include <stdbool.h> #include <stddef.h> @@ -229,8 +230,8 @@ struct qemu_plugin_insn; * @QEMU_PLUGIN_CB_R_REGS: callback reads the CPU's regs * @QEMU_PLUGIN_CB_RW_REGS: callback reads and writes the CPU's regs * - * Note: currently unused, plugins cannot read or change system - * register state. + * Note: currently QEMU_PLUGIN_CB_RW_REGS is unused, plugins cannot change + * system register state. */ enum qemu_plugin_cb_flags { QEMU_PLUGIN_CB_NO_REGS, @@ -707,4 +708,49 @@ uint64_t qemu_plugin_end_code(void); QEMU_PLUGIN_API uint64_t qemu_plugin_entry_code(void); +/** struct qemu_plugin_register - Opaque handle for register access */ +struct qemu_plugin_register; + +/** + * typedef qemu_plugin_reg_descriptor - register descriptions + * + * @handle: opaque handle for retrieving value with qemu_plugin_read_register + * @name: register name + * @feature: optional feature descriptor, can be NULL + */ +typedef struct { + struct qemu_plugin_register *handle; + const char *name; + const char *feature; +} qemu_plugin_reg_descriptor; + +/** + * qemu_plugin_get_registers() - return register list for current vCPU + * + * Returns a potentially empty GArray of qemu_plugin_reg_descriptor. + * Caller frees the array (but not the const strings). + * + * Should be used from a qemu_plugin_register_vcpu_init_cb() callback + * after the vCPU is initialised, i.e. in the vCPU context. + */ +QEMU_PLUGIN_API +GArray *qemu_plugin_get_registers(void); + +/** + * qemu_plugin_read_register() - read register for current vCPU + * + * @handle: a @qemu_plugin_reg_handle handle + * @buf: A GByteArray for the data owned by the plugin + * + * This function is only available in a context that register read access is + * explicitly requested via the QEMU_PLUGIN_CB_R_REGS flag. + * + * Returns the size of the read register. The content of @buf is in target byte + * order. On failure returns -1. + */ +QEMU_PLUGIN_API +int qemu_plugin_read_register(struct qemu_plugin_register *handle, + GByteArray *buf); + + #endif /* QEMU_QEMU_PLUGIN_H */ diff --git a/plugins/api.c b/plugins/api.c index 54df72c1c0..81f43c9ce8 100644 --- a/plugins/api.c +++ b/plugins/api.c @@ -8,6 +8,7 @@ * * qemu_plugin_tb * qemu_plugin_insn + * qemu_plugin_register * * Which can then be passed back into the API to do additional things. * As such all the public functions in here are exported in @@ -35,10 +36,12 @@ */ #include "qemu/osdep.h" +#include "qemu/main-loop.h" #include "qemu/plugin.h" #include "qemu/log.h" #include "tcg/tcg.h" #include "exec/exec-all.h" +#include "exec/gdbstub.h" #include "exec/ram_addr.h" #include "disas/disas.h" #include "plugin.h" @@ -410,3 +413,55 @@ uint64_t qemu_plugin_entry_code(void) #endif return entry; } + +/* + * Create register handles. + * + * We need to create a handle for each register so the plugin + * infrastructure can call gdbstub to read a register. They are + * currently just a pointer encapsulation of the gdb_reg but in + * future may hold internal plugin state so its important plugin + * authors are not tempted to treat them as numbers. + * + * We also construct a result array with those handles and some + * ancillary data the plugin might find useful. + */ + +static GArray *create_register_handles(GArray *gdbstub_regs) +{ + GArray *find_data = g_array_new(true, true, + sizeof(qemu_plugin_reg_descriptor)); + + for (int i = 0; i < gdbstub_regs->len; i++) { + GDBRegDesc *grd = &g_array_index(gdbstub_regs, GDBRegDesc, i); + qemu_plugin_reg_descriptor desc; + + /* skip "un-named" regs */ + if (!grd->name) { + continue; + } + + /* Create a record for the plugin */ + desc.handle = GINT_TO_POINTER(grd->gdb_reg); + desc.name = g_intern_string(grd->name); + desc.feature = g_intern_string(grd->feature_name); + g_array_append_val(find_data, desc); + } + + return find_data; +} + +GArray *qemu_plugin_get_registers(void) +{ + g_assert(current_cpu); + + g_autoptr(GArray) regs = gdb_get_register_list(current_cpu); + return create_register_handles(regs); +} + +int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) +{ + g_assert(current_cpu); + + return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg)); +} diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols index adb6760859..27fe97239b 100644 --- a/plugins/qemu-plugins.symbols +++ b/plugins/qemu-plugins.symbols @@ -3,6 +3,7 @@ qemu_plugin_end_code; qemu_plugin_entry_code; qemu_plugin_get_hwaddr; + qemu_plugin_get_registers; qemu_plugin_hwaddr_device_name; qemu_plugin_hwaddr_is_io; qemu_plugin_hwaddr_phys_addr; @@ -19,6 +20,7 @@ qemu_plugin_num_vcpus; qemu_plugin_outs; qemu_plugin_path_to_binary; + qemu_plugin_read_register; qemu_plugin_register_atexit_cb; qemu_plugin_register_flush_cb; qemu_plugin_register_vcpu_exit_cb; |