cpu: Turn cpu_get_memory_mapping() into a CPUState hook

Change error reporting from return value to Error argument.

Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
[AF: Fixed cpu_get_memory_mapping() documentation]
Signed-off-by: Andreas Färber <afaerber@suse.de>

include/qom/cpu.h

@@ -23,6 +23,7 @@
 #include <signal.h>
 #include "hw/qdev-core.h"
 #include "qemu/thread.h"
+#include "qemu/typedefs.h"
 
 typedef int (*WriteCoreDumpFunction)(void *buf, size_t size, void *opaque);
 
@@ -49,6 +50,7 @@ typedef struct CPUState CPUState;
  * @do_interrupt: Callback for interrupt handling.
  * @get_arch_id: Callback for getting architecture-dependent CPU ID.
  * @get_paging_enabled: Callback for inquiring whether paging is enabled.
+ * @get_memory_mapping: Callback for obtaining the memory mappings.
  * @vmsd: State description for migration.
  *
  * Represents a CPU family or model.
@@ -64,6 +66,8 @@ typedef struct CPUClass {
     void (*do_interrupt)(CPUState *cpu);
     int64_t (*get_arch_id)(CPUState *cpu);
     bool (*get_paging_enabled)(const CPUState *cpu);
+    void (*get_memory_mapping)(CPUState *cpu, MemoryMappingList *list,
+                               Error **errp);
 
     const struct VMStateDescription *vmsd;
     int (*write_elf64_note)(WriteCoreDumpFunction f, CPUState *cpu,
@@ -147,6 +151,15 @@ struct CPUState {
  */
 bool cpu_paging_enabled(const CPUState *cpu);
 
+/**
+ * cpu_get_memory_mapping:
+ * @cpu: The CPU whose memory mappings are to be obtained.
+ * @list: Where to write the memory mappings to.
+ * @errp: Pointer for reporting an #Error.
+ */
+void cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
+                            Error **errp);
+
 /**
  * cpu_write_elf64_note:
  * @f: pointer to a function that writes memory to a file

include/sysemu/memory_mapping.h

@@ -31,8 +31,6 @@ struct MemoryMappingList {
     QTAILQ_HEAD(, MemoryMapping) head;
 };
 
-int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env);
-
 /*
  * add or merge the memory region [phys_addr, phys_addr + length) into the
  * memory mapping's list. The region's virtual address starts with virt_addr,

memory_mapping-stub.c

@@ -19,9 +19,3 @@ int qemu_get_guest_memory_mapping(MemoryMappingList *list)
 {
     return -2;
 }
-
-int cpu_get_memory_mapping(MemoryMappingList *list,
-					                                          CPUArchState *env)
-{
-    return -1;
-}

memory_mapping.c

@@ -183,13 +183,14 @@ int qemu_get_guest_memory_mapping(MemoryMappingList *list)
     CPUArchState *env, *first_paging_enabled_cpu;
     RAMBlock *block;
     ram_addr_t offset, length;
-    int ret;
 
     first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
     if (first_paging_enabled_cpu) {
         for (env = first_paging_enabled_cpu; env != NULL; env = env->next_cpu) {
-            ret = cpu_get_memory_mapping(list, env);
+            Error *err = NULL;
-            if (ret < 0) {
+            cpu_get_memory_mapping(ENV_GET_CPU(env), list, &err);
+            if (err) {
+                error_free(err);
                 return -1;
             }
         }

qom/cpu.c

@@ -62,6 +62,21 @@ static bool cpu_common_get_paging_enabled(const CPUState *cpu)
     return true;
 }
 
+void cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
+                            Error **errp)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
+    return cc->get_memory_mapping(cpu, list, errp);
+}
+
+static void cpu_common_get_memory_mapping(CPUState *cpu,
+                                          MemoryMappingList *list,
+                                          Error **errp)
+{
+    error_setg(errp, "Obtaining memory mappings is unsupported on this CPU.");
+}
+
 /* CPU hot-plug notifiers */
 static NotifierList cpu_added_notifiers =
     NOTIFIER_LIST_INITIALIZER(cpu_add_notifiers);
@@ -189,6 +204,7 @@ static void cpu_class_init(ObjectClass *klass, void *data)
     k->reset = cpu_common_reset;
     k->get_arch_id = cpu_common_get_arch_id;
     k->get_paging_enabled = cpu_common_get_paging_enabled;
+    k->get_memory_mapping = cpu_common_get_memory_mapping;
     k->write_elf32_qemunote = cpu_common_write_elf32_qemunote;
     k->write_elf32_note = cpu_common_write_elf32_note;
     k->write_elf64_qemunote = cpu_common_write_elf64_qemunote;

target-i386/arch_memory_mapping.c

@@ -239,11 +239,15 @@ static void walk_pml4e(MemoryMappingList *list,
 }
 #endif
 
-int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env)
+void x86_cpu_get_memory_mapping(CPUState *cs, MemoryMappingList *list,
+                                Error **errp)
 {
-    if (!cpu_paging_enabled(ENV_GET_CPU(env))) {
+    X86CPU *cpu = X86_CPU(cs);
+    CPUX86State *env = &cpu->env;
+
+    if (!cpu_paging_enabled(cs)) {
         /* paging is disabled */
-        return 0;
+        return;
     }
 
     if (env->cr[4] & CR4_PAE_MASK) {
@@ -269,7 +273,5 @@ int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env)
         pse = !!(env->cr[4] & CR4_PSE_MASK);
         walk_pde2(list, pde_addr, env->a20_mask, pse);
     }
-
-    return 0;
 }
 

target-i386/cpu-qom.h

@@ -98,4 +98,7 @@ int x86_cpu_write_elf64_qemunote(WriteCoreDumpFunction f, CPUState *cpu,
 int x86_cpu_write_elf32_qemunote(WriteCoreDumpFunction f, CPUState *cpu,
                                  void *opaque);
 
+void x86_cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
+                                Error **errp);
+
 #endif

target-i386/cpu.c

@@ -2529,6 +2529,7 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
     cc->get_arch_id = x86_cpu_get_arch_id;
     cc->get_paging_enabled = x86_cpu_get_paging_enabled;
 #ifndef CONFIG_USER_ONLY
+    cc->get_memory_mapping = x86_cpu_get_memory_mapping;
     cc->write_elf64_note = x86_cpu_write_elf64_note;
     cc->write_elf64_qemunote = x86_cpu_write_elf64_qemunote;
     cc->write_elf32_note = x86_cpu_write_elf32_note;