arm: move KVM breakpoints helpers

These helpers will be also used for HVF. Aside from reformatting a
couple of comments for 'checkpatch.pl' and updating meson to compile
'hyp_gdbstub.c', this is just code motion.

Signed-off-by: Francesco Cagnin <fcagnin@quarkslab.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230601153107.81955-2-fcagnin@quarkslab.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/target/arm/internals.h b/target/arm/internals.h
index c869d18c38..ce26299f7f 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1447,4 +1447,54 @@ static inline bool arm_fgt_active(CPUARMState *env, int el)
 }
 
 void assert_hflags_rebuild_correctly(CPUARMState *env);
+
+/*
+ * Although the ARM implementation of hardware assisted debugging
+ * allows for different breakpoints per-core, the current GDB
+ * interface treats them as a global pool of registers (which seems to
+ * be the case for x86, ppc and s390). As a result we store one copy
+ * of registers which is used for all active cores.
+ *
+ * Write access is serialised by virtue of the GDB protocol which
+ * updates things. Read access (i.e. when the values are copied to the
+ * vCPU) is also gated by GDB's run control.
+ *
+ * This is not unreasonable as most of the time debugging kernels you
+ * never know which core will eventually execute your function.
+ */
+
+typedef struct {
+    uint64_t bcr;
+    uint64_t bvr;
+} HWBreakpoint;
+
+/*
+ * The watchpoint registers can cover more area than the requested
+ * watchpoint so we need to store the additional information
+ * somewhere. We also need to supply a CPUWatchpoint to the GDB stub
+ * when the watchpoint is hit.
+ */
+typedef struct {
+    uint64_t wcr;
+    uint64_t wvr;
+    CPUWatchpoint details;
+} HWWatchpoint;
+
+/* Maximum and current break/watch point counts */
+extern int max_hw_bps, max_hw_wps;
+extern GArray *hw_breakpoints, *hw_watchpoints;
+
+#define cur_hw_wps      (hw_watchpoints->len)
+#define cur_hw_bps      (hw_breakpoints->len)
+#define get_hw_bp(i)    (&g_array_index(hw_breakpoints, HWBreakpoint, i))
+#define get_hw_wp(i)    (&g_array_index(hw_watchpoints, HWWatchpoint, i))
+
+bool find_hw_breakpoint(CPUState *cpu, target_ulong pc);
+int insert_hw_breakpoint(target_ulong pc);
+int delete_hw_breakpoint(target_ulong pc);
+
+bool check_watchpoint_in_range(int i, target_ulong addr);
+CPUWatchpoint *find_hw_watchpoint(CPUState *cpu, target_ulong addr);
+int insert_hw_watchpoint(target_ulong addr, target_ulong len, int type);
+int delete_hw_watchpoint(target_ulong addr, target_ulong len, int type);
 #endif