@@ -53,6 +53,20 @@ struct TCGCPUOps {
/** @debug_excp_handler: Callback for handling debug exceptions */
void (*debug_excp_handler)(CPUState *cpu);
+ /**
+ * @plugin_need_unwind_for_reg:
+ * True if unwind info needed for reading reg.
+ */
+ bool (*plugin_need_unwind_for_reg)(CPUState *cpu, int reg);
+ /**
+ * @plugin_unwind_read_reg:
+ * Like CPUClass.gdb_read_register, but for registers that require
+ * regeneration using unwind info, like in @restore_state_to_opc.
+ */
+ int (*plugin_unwind_read_reg)(CPUState *cpu, GByteArray *buf, int reg,
+ const TranslationBlock *tb,
+ const uint64_t *data);
+
#ifdef CONFIG_USER_ONLY
/**
* @fake_user_interrupt: Callback for 'fake exception' handling.
@@ -40,10 +40,12 @@
#include "qemu/plugin.h"
#include "qemu/log.h"
#include "tcg/tcg.h"
+#include "tcg/insn-start-words.h"
#include "exec/exec-all.h"
#include "exec/gdbstub.h"
#include "exec/translator.h"
#include "disas/disas.h"
+#include "hw/core/tcg-cpu-ops.h"
#include "plugin.h"
#ifndef CONFIG_USER_ONLY
#include "exec/ram_addr.h"
@@ -526,9 +528,39 @@ GArray *qemu_plugin_get_registers(void)
int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf)
{
- g_assert(current_cpu);
+ CPUState *cs;
+ uintptr_t ra;
+ int regno;
- return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg));
+ assert(current_cpu);
+ cs = current_cpu;
+ ra = cs->neg.plugin_ra;
+ regno = GPOINTER_TO_INT(reg);
+
+ /*
+ * When plugin_ra is 0, we have no unwind info. This will be true for
+ * TB callbacks that happen before any insns of the TB have started.
+ */
+ if (ra) {
+ const TCGCPUOps *tcg_ops = cs->cc->tcg_ops;
+
+ /*
+ * For plugins in the middle of the TB, we may need to locate
+ * and use unwind data to reconstruct a register value.
+ * Usually this required for the PC, but there may be others.
+ */
+ if (tcg_ops->plugin_need_unwind_for_reg &&
+ tcg_ops->plugin_need_unwind_for_reg(cs, regno)) {
+ uint64_t data[TARGET_INSN_START_WORDS];
+ const TranslationBlock *tb;
+
+ tb = cpu_unwind_state_data(cs, ra, data);
+ assert(tb);
+ return tcg_ops->plugin_unwind_read_reg(cs, buf, regno, tb, data);
+ }
+ }
+
+ return gdb_read_register(cs, buf, regno);
}
struct qemu_plugin_scoreboard *qemu_plugin_scoreboard_new(size_t element_size)