Re: [Qemu-devel] [PATCH] minor x86-64 corrections

[Filip Navara]

[snip]

> > Maybe the SS segment cache should be set to zero ?
>
> I'm not sure really, but I guess you're right.
>
> MOV documentation:
> ... "It is possible to move a null segment selector value (0000–0003h) 
> into the DS, ES, FS,
> or GS register. This action does not cause a general protection fault, 
> but a subsequent
> reference to such a segment does cause a #GP exception. For more 
> information about
> segment selectors, see “Segment Selectors and Registers” on page 84." ...
>
> GPF is exception is thrown if ... "The SS register was loaded with a 
> null segment selector in non-64-bit mode or while CPL = 3." ...

I looked at the disassembly and it's called after setting up GDT and 
IDT. Does the attached patch look better?

Regards,
Filip

Index: hw/apic.c
===================================================================
RCS file: /cvsroot/qemu/qemu/hw/apic.c,v
retrieving revision 1.1
diff -u -r1.1 apic.c
--- hw/apic.c   3 Jan 2005 23:27:31 -0000       1.1
+++ hw/apic.c   21 Jan 2005 20:13:30 -0000
@@ -100,6 +100,18 @@
     return s->apicbase;
 }
 
+void cpu_set_apic_tpr(CPUState *env, uint8_t val)
+{
+    APICState *s = env->apic_state;
+    s->tpr = val;
+}
+
+uint8_t cpu_get_apic_tpr(CPUState *env)
+{
+    APICState *s = env->apic_state;
+    return s->tpr;
+}
+
 /* return -1 if no bit is set */
 static int get_highest_priority_int(uint32_t *tab)
 {
Index: target-i386/exec.h
===================================================================
RCS file: /cvsroot/qemu/qemu/target-i386/exec.h,v
retrieving revision 1.20
diff -u -r1.20 exec.h
--- target-i386/exec.h  8 Jan 2005 18:58:29 -0000       1.20
+++ target-i386/exec.h  21 Jan 2005 20:23:30 -0000
@@ -167,6 +167,8 @@
 void cpu_x86_flush_tlb(CPUX86State *env, uint32_t addr);
 int cpu_x86_handle_mmu_fault(CPUX86State *env, target_ulong addr, 
                              int is_write, int is_user, int is_softmmu);
+void cpu_set_apic_tpr(CPUX86State *env, uint8_t val);
+uint8_t cpu_get_apic_tpr(CPUX86State *env);
 void tlb_fill(target_ulong addr, int is_write, int is_user, 
               void *retaddr);
 void __hidden cpu_lock(void);
Index: target-i386/helper.c
===================================================================
RCS file: /cvsroot/qemu/qemu/target-i386/helper.c,v
retrieving revision 1.40
diff -u -r1.40 helper.c
--- target-i386/helper.c        16 Jan 2005 23:35:43 -0000      1.40
+++ target-i386/helper.c        21 Jan 2005 22:18:01 -0000
@@ -1454,8 +1454,12 @@
     selector &= 0xffff;
     if ((selector & 0xfffc) == 0) {
         /* null selector case */
-        if (seg_reg == R_SS)
-            raise_exception_err(EXCP0D_GPF, 0);
+        if (seg_reg == R_SS) {
+#ifdef TARGET_X86_64
+            if (!env->hflags & HF_CS64_MASK)
+#endif
+                raise_exception_err(EXCP0D_GPF, 0);
+        }
         cpu_x86_load_seg_cache(env, seg_reg, selector, 0, 0, 0);
     } else {
         
@@ -2156,6 +2160,11 @@
     case 4:
         cpu_x86_update_cr4(env, T0);
         break;
+#ifdef TARGET_X86_64
+    case 8:
+        cpu_set_apic_tpr(env, (T0 & 0xf) << 4);
+        break;
+#endif
     default:
         env->cr[reg] = T0;
         break;
Index: target-i386/op.c
===================================================================
RCS file: /cvsroot/qemu/qemu/target-i386/op.c,v
retrieving revision 1.28
diff -u -r1.28 op.c
--- target-i386/op.c    9 Jan 2005 00:07:04 -0000       1.28
+++ target-i386/op.c    21 Jan 2005 22:09:18 -0000
@@ -1198,6 +1198,11 @@
     helper_movl_crN_T0(PARAM1);
 }
 
+void OPPROTO op_movtl_T0_cr8(void)
+{
+    T0 = (cpu_get_apic_tpr(env) & 0xf) >> 4;
+}
+
 /* DR registers access */
 void OPPROTO op_movl_drN_T0(void)
 {
Index: target-i386/translate.c
===================================================================
RCS file: /cvsroot/qemu/qemu/target-i386/translate.c,v
retrieving revision 1.41
diff -u -r1.41 translate.c
--- target-i386/translate.c     16 Jan 2005 01:07:28 -0000      1.41
+++ target-i386/translate.c     21 Jan 2005 22:09:23 -0000
@@ -5641,7 +5641,19 @@
                     gen_op_mov_reg_T0[ot][rm]();
                 }
                 break;
-                /* XXX: add CR8 for x86_64 */
+#ifdef TARGET_X86_64
+            case 8:
+                if (b & 2) {
+                    gen_op_mov_TN_reg[ot][0][rm]();
+                    gen_op_movl_crN_T0(reg);
+                    gen_jmp_im(s->pc - s->cs_base);
+                    gen_eob(s);
+                } else {
+                    gen_op_movtl_T0_cr8();
+                    gen_op_mov_reg_T0[ot][rm]();
+                }
+                break;
+#endif
             default:
                 goto illegal_op;
             }