correct CPL support (should fix flat real mode support)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@343 c046a42c-6fe2-441c-8c8c-71466251a162

cpu-exec.c

@@ -244,13 +244,8 @@ int cpu_exec(CPUState *env1)
                            (unsigned long)env->segs[R_ES].base |
                            (unsigned long)env->segs[R_SS].base) != 0) << 
                     GEN_FLAG_ADDSEG_SHIFT;
-                if (env->cr[0] & CR0_PE_MASK) {
-                    if (!(env->eflags & VM_MASK))
-                        flags |= (env->segs[R_CS].selector & 3) << 
-                            GEN_FLAG_CPL_SHIFT;
-                    else
-                        flags |= (1 << GEN_FLAG_VM_SHIFT);
-                }
+                flags |= env->cpl << GEN_FLAG_CPL_SHIFT;
+                flags |= (env->eflags & VM_MASK) >> (17 - GEN_FLAG_VM_SHIFT);
                 flags |= (env->eflags & (IOPL_MASK | TF_MASK));
                 cs_base = env->segs[R_CS].base;
                 pc = cs_base + env->eip;

cpu-i386.h

@@ -256,6 +256,7 @@ typedef struct CPUX86State {
     SegmentCache tr;
     SegmentCache gdt; /* only base and limit are used */
     SegmentCache idt; /* only base and limit are used */
+    int cpl;          /* current cpl */
 
     /* sysenter registers */
     uint32_t sysenter_cs;
@@ -276,6 +277,7 @@ typedef struct CPUX86State {
 
     uint32_t breakpoints[MAX_BREAKPOINTS];
     int nb_breakpoints;
+    int singlestep_enabled;
     
     /* user data */
     void *opaque;
@@ -298,6 +300,12 @@ int cpu_x86_get_pic_interrupt(CPUX86State *s);
 /* needed to load some predefinied segment registers */
 void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector);
 
+/* wrapper, just in case memory mappings must be changed */
+static inline void cpu_x86_set_cpl(CPUX86State *s, int cpl)
+{
+    s->cpl = cpl;
+}
+
 /* simulate fsave/frstor */
 void cpu_x86_fsave(CPUX86State *s, uint8_t *ptr, int data32);
 void cpu_x86_frstor(CPUX86State *s, uint8_t *ptr, int data32);

helper-i386.c

@@ -189,7 +189,7 @@ static void do_interrupt_protected(int intno, int is_int, int error_code,
 {
     SegmentCache *dt;
     uint8_t *ptr, *ssp;
-    int type, dpl, cpl, selector, ss_dpl;
+    int type, dpl, selector, ss_dpl;
     int has_error_code, new_stack, shift;
     uint32_t e1, e2, offset, ss, esp, ss_e1, ss_e2, push_size;
     uint32_t old_cs, old_ss, old_esp, old_eip;
@@ -216,12 +216,8 @@ static void do_interrupt_protected(int intno, int is_int, int error_code,
         break;
     }
     dpl = (e2 >> DESC_DPL_SHIFT) & 3;
-    if (env->eflags & VM_MASK)
-        cpl = 3;
-    else
-        cpl = env->segs[R_CS].selector & 3;
     /* check privledge if software int */
-    if (is_int && dpl < cpl)
+    if (is_int && dpl < env->cpl)
         raise_exception_err(EXCP0D_GPF, intno * 8 + 2);
     /* check valid bit */
     if (!(e2 & DESC_P_MASK))
@@ -236,11 +232,11 @@ static void do_interrupt_protected(int intno, int is_int, int error_code,
     if (!(e2 & DESC_S_MASK) || !(e2 & (DESC_CS_MASK)))
         raise_exception_err(EXCP0D_GPF, selector & 0xfffc);
     dpl = (e2 >> DESC_DPL_SHIFT) & 3;
-    if (dpl > cpl)
+    if (dpl > env->cpl)
         raise_exception_err(EXCP0D_GPF, selector & 0xfffc);
     if (!(e2 & DESC_P_MASK))
         raise_exception_err(EXCP0B_NOSEG, selector & 0xfffc);
-    if (!(e2 & DESC_C_MASK) && dpl < cpl) {
+    if (!(e2 & DESC_C_MASK) && dpl < env->cpl) {
         /* to inner priviledge */
         get_ss_esp_from_tss(&ss, &esp, dpl);
         if ((ss & 0xfffc) == 0)
@@ -259,7 +255,7 @@ static void do_interrupt_protected(int intno, int is_int, int error_code,
         if (!(ss_e2 & DESC_P_MASK))
             raise_exception_err(EXCP0A_TSS, ss & 0xfffc);
         new_stack = 1;
-    } else if ((e2 & DESC_C_MASK) || dpl == cpl) {
+    } else if ((e2 & DESC_C_MASK) || dpl == env->cpl) {
         /* to same priviledge */
         new_stack = 0;
     } else {
@@ -406,7 +402,7 @@ void do_interrupt_user(int intno, int is_int, int error_code,
 {
     SegmentCache *dt;
     uint8_t *ptr;
-    int dpl, cpl;
+    int dpl;
     uint32_t e2;
 
     dt = &env->idt;
@@ -414,9 +410,8 @@ void do_interrupt_user(int intno, int is_int, int error_code,
     e2 = ldl(ptr + 4);
     
     dpl = (e2 >> DESC_DPL_SHIFT) & 3;
-    cpl = 3;
     /* check privledge if software int */
-    if (is_int && dpl < cpl)
+    if (is_int && dpl < env->cpl)
         raise_exception_err(EXCP0D_GPF, intno * 8 + 2);
 
     /* Since we emulate only user space, we cannot do more than
@@ -728,6 +723,9 @@ void load_seg(int seg_reg, int selector, unsigned int cur_eip)
                 selector, (unsigned long)sc->base, sc->limit, sc->flags);
 #endif
     }
+    if (seg_reg == R_CS) {
+        cpu_x86_set_cpl(env, selector & 3);
+    }
     sc->selector = selector;
 }
 
@@ -744,7 +742,7 @@ void helper_ljmp_protected_T0_T1(void)
         raise_exception_err(EXCP0D_GPF, 0);
     if (load_segment(&e1, &e2, new_cs) != 0)
         raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc);
-    cpl = env->segs[R_CS].selector & 3;
+    cpl = env->cpl;
     if (e2 & DESC_S_MASK) {
         if (!(e2 & DESC_CS_MASK))
             raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc);
@@ -828,7 +826,7 @@ void helper_lcall_protected_T0_T1(int shift, int next_eip)
         raise_exception_err(EXCP0D_GPF, 0);
     if (load_segment(&e1, &e2, new_cs) != 0)
         raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc);
-    cpl = env->segs[R_CS].selector & 3;
+    cpl = env->cpl;
     if (e2 & DESC_S_MASK) {
         if (!(e2 & DESC_CS_MASK))
             raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc);
@@ -1081,7 +1079,7 @@ static inline void helper_ret_protected(int shift, int is_iret, int addend)
     if (!(e2 & DESC_S_MASK) ||
         !(e2 & DESC_CS_MASK))
         raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc);
-    cpl = env->segs[R_CS].selector & 3;
+    cpl = env->cpl;
     rpl = new_cs & 3; 
     if (rpl < cpl)
         raise_exception_err(EXCP0D_GPF, new_cs & 0xfffc);
@@ -1158,12 +1156,13 @@ static inline void helper_ret_protected(int shift, int is_iret, int addend)
     /* modify processor state */
     load_eflags(new_eflags, FL_UPDATE_CPL0_MASK | VM_MASK | VIF_MASK | VIP_MASK);
     load_seg_vm(R_CS, new_cs);
+    cpu_x86_set_cpl(env, 3);
     load_seg_vm(R_SS, new_ss);
     load_seg_vm(R_ES, new_es);
     load_seg_vm(R_DS, new_ds);
     load_seg_vm(R_FS, new_fs);
     load_seg_vm(R_GS, new_gs);
-    
+
     env->eip = new_eip;
     env->regs[R_ESP] = new_esp;
 }

translate-i386.c

@@ -4113,13 +4113,7 @@ static inline int gen_intermediate_code_internal(CPUState *env,
     dc->addseg = (flags >> GEN_FLAG_ADDSEG_SHIFT) & 1;
     dc->f_st = (flags >> GEN_FLAG_ST_SHIFT) & 7;
     dc->vm86 = (flags >> GEN_FLAG_VM_SHIFT) & 1;
-    /* CPL is implicit if real mode or vm86 mode */
-    if (!dc->pe)
-        dc->cpl = 0;
-    else if (dc->vm86)
-        dc->cpl = 3;
-    else
-        dc->cpl = (flags >> GEN_FLAG_CPL_SHIFT) & 3;
+    dc->cpl = (flags >> GEN_FLAG_CPL_SHIFT) & 3;
     dc->iopl = (flags >> GEN_FLAG_IOPL_SHIFT) & 3;
     dc->tf = (flags >> GEN_FLAG_TF_SHIFT) & 1;
     dc->cc_op = CC_OP_DYNAMIC;
@@ -4362,7 +4356,7 @@ int cpu_x86_handle_mmu_fault(CPUX86State *env, uint32_t addr, int is_write)
     int cpl, error_code, is_dirty, is_user, prot, page_size;
     void *map_addr;
 
-    cpl = env->segs[R_CS].selector & 3;
+    cpl = env->cpl;
     is_user = (cpl == 3);
     
 #ifdef DEBUG_MMU