x86: Debug register emulation (Jan Kiszka)
Built on top of previously enhanced breakpoint/watchpoint support, this
patch adds full debug register emulation for the x86 architecture.
Many corner cases were considered, and the result was successfully
tested inside a Linux guest with gdb, but I won't be surprised if one
or two scenarios still behave differently in reality.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5747 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/target-i386/helper.c b/target-i386/helper.c
index baa99c9..0cfef44 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -34,8 +34,6 @@
//#define DEBUG_MMU
-static int cpu_x86_register (CPUX86State *env, const char *cpu_model);
-
static void add_flagname_to_bitmaps(char *flagname, uint32_t *features,
uint32_t *ext_features,
uint32_t *ext2_features,
@@ -93,35 +91,6 @@
fprintf(stderr, "CPU feature %s not found\n", flagname);
}
-CPUX86State *cpu_x86_init(const char *cpu_model)
-{
- CPUX86State *env;
- static int inited;
-
- env = qemu_mallocz(sizeof(CPUX86State));
- if (!env)
- return NULL;
- cpu_exec_init(env);
- env->cpu_model_str = cpu_model;
-
- /* init various static tables */
- if (!inited) {
- inited = 1;
- optimize_flags_init();
- }
- if (cpu_x86_register(env, cpu_model) < 0) {
- cpu_x86_close(env);
- return NULL;
- }
- cpu_reset(env);
-#ifdef USE_KQEMU
- kqemu_init(env);
-#endif
- if (kvm_enabled())
- kvm_init_vcpu(env);
- return env;
-}
-
typedef struct x86_def_t {
const char *name;
uint32_t level;
@@ -499,6 +468,12 @@
env->fpuc = 0x37f;
env->mxcsr = 0x1f80;
+
+ memset(env->dr, 0, sizeof(env->dr));
+ env->dr[6] = DR6_FIXED_1;
+ env->dr[7] = DR7_FIXED_1;
+ cpu_breakpoint_remove_all(env, BP_CPU);
+ cpu_watchpoint_remove_all(env, BP_CPU);
}
void cpu_x86_close(CPUX86State *env)
@@ -1295,6 +1270,105 @@
paddr = (pte & TARGET_PAGE_MASK) + page_offset;
return paddr;
}
+
+void hw_breakpoint_insert(CPUState *env, int index)
+{
+ int type, err = 0;
+
+ switch (hw_breakpoint_type(env->dr[7], index)) {
+ case 0:
+ if (hw_breakpoint_enabled(env->dr[7], index))
+ err = cpu_breakpoint_insert(env, env->dr[index], BP_CPU,
+ &env->cpu_breakpoint[index]);
+ break;
+ case 1:
+ type = BP_CPU | BP_MEM_WRITE;
+ goto insert_wp;
+ case 2:
+ /* No support for I/O watchpoints yet */
+ break;
+ case 3:
+ type = BP_CPU | BP_MEM_ACCESS;
+ insert_wp:
+ err = cpu_watchpoint_insert(env, env->dr[index],
+ hw_breakpoint_len(env->dr[7], index),
+ type, &env->cpu_watchpoint[index]);
+ break;
+ }
+ if (err)
+ env->cpu_breakpoint[index] = NULL;
+}
+
+void hw_breakpoint_remove(CPUState *env, int index)
+{
+ if (!env->cpu_breakpoint[index])
+ return;
+ switch (hw_breakpoint_type(env->dr[7], index)) {
+ case 0:
+ if (hw_breakpoint_enabled(env->dr[7], index))
+ cpu_breakpoint_remove_by_ref(env, env->cpu_breakpoint[index]);
+ break;
+ case 1:
+ case 3:
+ cpu_watchpoint_remove_by_ref(env, env->cpu_watchpoint[index]);
+ break;
+ case 2:
+ /* No support for I/O watchpoints yet */
+ break;
+ }
+}
+
+int check_hw_breakpoints(CPUState *env, int force_dr6_update)
+{
+ target_ulong dr6;
+ int reg, type;
+ int hit_enabled = 0;
+
+ dr6 = env->dr[6] & ~0xf;
+ for (reg = 0; reg < 4; reg++) {
+ type = hw_breakpoint_type(env->dr[7], reg);
+ if ((type == 0 && env->dr[reg] == env->eip) ||
+ ((type & 1) && env->cpu_watchpoint[reg] &&
+ (env->cpu_watchpoint[reg]->flags & BP_WATCHPOINT_HIT))) {
+ dr6 |= 1 << reg;
+ if (hw_breakpoint_enabled(env->dr[7], reg))
+ hit_enabled = 1;
+ }
+ }
+ if (hit_enabled || force_dr6_update)
+ env->dr[6] = dr6;
+ return hit_enabled;
+}
+
+static CPUDebugExcpHandler *prev_debug_excp_handler;
+
+void raise_exception(int exception_index);
+
+static void breakpoint_handler(CPUState *env)
+{
+ CPUBreakpoint *bp;
+
+ if (env->watchpoint_hit) {
+ if (env->watchpoint_hit->flags & BP_CPU) {
+ env->watchpoint_hit = NULL;
+ if (check_hw_breakpoints(env, 0))
+ raise_exception(EXCP01_DB);
+ else
+ cpu_resume_from_signal(env, NULL);
+ }
+ } else {
+ for (bp = env->breakpoints; bp != NULL; bp = bp->next)
+ if (bp->pc == env->eip) {
+ if (bp->flags & BP_CPU) {
+ check_hw_breakpoints(env, 1);
+ raise_exception(EXCP01_DB);
+ }
+ break;
+ }
+ }
+ if (prev_debug_excp_handler)
+ prev_debug_excp_handler(env);
+}
#endif /* !CONFIG_USER_ONLY */
static void host_cpuid(uint32_t function, uint32_t *eax, uint32_t *ebx,
@@ -1532,3 +1606,36 @@
break;
}
}
+
+CPUX86State *cpu_x86_init(const char *cpu_model)
+{
+ CPUX86State *env;
+ static int inited;
+
+ env = qemu_mallocz(sizeof(CPUX86State));
+ if (!env)
+ return NULL;
+ cpu_exec_init(env);
+ env->cpu_model_str = cpu_model;
+
+ /* init various static tables */
+ if (!inited) {
+ inited = 1;
+ optimize_flags_init();
+#ifndef CONFIG_USER_ONLY
+ prev_debug_excp_handler =
+ cpu_set_debug_excp_handler(breakpoint_handler);
+#endif
+ }
+ if (cpu_x86_register(env, cpu_model) < 0) {
+ cpu_x86_close(env);
+ return NULL;
+ }
+ cpu_reset(env);
+#ifdef USE_KQEMU
+ kqemu_init(env);
+#endif
+ if (kvm_enabled())
+ kvm_init_vcpu(env);
+ return env;
+}
