Fix wrong behavior of cpu_memory_rw_debug() function in SMM

There is a problem, that you don't have access to the data using cpu_memory_rw_debug() function when in SMM. You can't remotely debug SMM mode program because of that for example.
Likely attrs version of get_phys_page_debug should be used to get correct asidx at the end to handle access properly.
Here the patch to fix it.

Signed-off-by: Dmitry Poletaev <poletaev@ispras.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

@@ -5984,7 +5984,7 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
 #ifndef CONFIG_USER_ONLY
     cc->asidx_from_attrs = x86_asidx_from_attrs;
     cc->get_memory_mapping = x86_cpu_get_memory_mapping;
-    cc->get_phys_page_debug = x86_cpu_get_phys_page_debug;
+    cc->get_phys_page_attrs_debug = x86_cpu_get_phys_page_attrs_debug;
     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;

target/i386/cpu.h

@@ -1551,7 +1551,8 @@ void x86_cpu_get_memory_mapping(CPUState *cpu, MemoryMappingList *list,
 
 void x86_cpu_dump_state(CPUState *cs, FILE *f, int flags);
 
-hwaddr x86_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
+hwaddr x86_cpu_get_phys_page_attrs_debug(CPUState *cpu, vaddr addr,
+                                         MemTxAttrs *attrs);
 
 int x86_cpu_gdb_read_register(CPUState *cpu, uint8_t *buf, int reg);
 int x86_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);

target/i386/helper.c

@@ -715,7 +715,8 @@ void cpu_x86_update_cr4(CPUX86State *env, uint32_t new_cr4)
 }
 
 #if !defined(CONFIG_USER_ONLY)
-hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
+hwaddr x86_cpu_get_phys_page_attrs_debug(CPUState *cs, vaddr addr,
+                                         MemTxAttrs *attrs)
 {
     X86CPU *cpu = X86_CPU(cs);
     CPUX86State *env = &cpu->env;
@@ -725,6 +726,8 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
     uint32_t page_offset;
     int page_size;
 
+    *attrs = cpu_get_mem_attrs(env);
+
     a20_mask = x86_get_a20_mask(env);
     if (!(env->cr[0] & CR0_PG_MASK)) {
         pte = addr & a20_mask;