Userspace guest address offsetting

Re-implement GUEST_BASE support.
Offset guest ddress space by default if the guest binary contains
regions below the host mmap_min_addr.
Implement support for i386, x86-64 and arm hosts.

Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Paul Brook <paul@codesourcery.com>

2 files changed, 22 insertions, 16 deletions

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index e0fd434..ed61780 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -427,6 +427,10 @@ static void *qemu_st_helpers[4] = {
 };
 #endif
 
+#ifndef CONFIG_USER_ONLY
+#define GUEST_BASE 0
+#endif
+
 /* XXX: qemu_ld and qemu_st could be modified to clobber only EDX and
    EAX. It will be useful once fixed registers globals are less
    common. */
@@ -572,15 +576,15 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
     switch(opc) {
     case 0:
         /* movzbl */
-        tcg_out_modrm_offset(s, 0xb6 | P_EXT, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0xb6 | P_EXT, data_reg, r0, GUEST_BASE);
         break;
     case 0 | 4:
         /* movsbl */
-        tcg_out_modrm_offset(s, 0xbe | P_EXT, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0xbe | P_EXT, data_reg, r0, GUEST_BASE);
         break;
     case 1:
         /* movzwl */
-        tcg_out_modrm_offset(s, 0xb7 | P_EXT, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0xb7 | P_EXT, data_reg, r0, GUEST_BASE);
         if (bswap) {
             /* rolw $8, data_reg */
             tcg_out8(s, 0x66); 
@@ -590,7 +594,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
         break;
     case 1 | 4:
         /* movswl */
-        tcg_out_modrm_offset(s, 0xbf | P_EXT, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0xbf | P_EXT, data_reg, r0, GUEST_BASE);
         if (bswap) {
             /* rolw $8, data_reg */
             tcg_out8(s, 0x66); 
@@ -603,7 +607,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
         break;
     case 2:
         /* movl (r0), data_reg */
-        tcg_out_modrm_offset(s, 0x8b, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x8b, data_reg, r0, GUEST_BASE);
         if (bswap) {
             /* bswap */
             tcg_out_opc(s, (0xc8 + data_reg) | P_EXT);
@@ -619,13 +623,13 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
             r0 = r1;
         }
         if (!bswap) {
-            tcg_out_modrm_offset(s, 0x8b, data_reg, r0, 0);
-            tcg_out_modrm_offset(s, 0x8b, data_reg2, r0, 4);
+            tcg_out_modrm_offset(s, 0x8b, data_reg, r0, GUEST_BASE);
+            tcg_out_modrm_offset(s, 0x8b, data_reg2, r0, GUEST+BASE + 4);
         } else {
-            tcg_out_modrm_offset(s, 0x8b, data_reg, r0, 4);
+            tcg_out_modrm_offset(s, 0x8b, data_reg, r0, GUEST_BASE + 4);
             tcg_out_opc(s, (0xc8 + data_reg) | P_EXT);
 
-            tcg_out_modrm_offset(s, 0x8b, data_reg2, r0, 0);
+            tcg_out_modrm_offset(s, 0x8b, data_reg2, r0, GUEST_BASE);
             /* bswap */
             tcg_out_opc(s, (0xc8 + data_reg2) | P_EXT);
         }
@@ -806,7 +810,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
     switch(opc) {
     case 0:
         /* movb */
-        tcg_out_modrm_offset(s, 0x88, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x88, data_reg, r0, GUEST_BASE);
         break;
     case 1:
         if (bswap) {
@@ -818,7 +822,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
         }
         /* movw */
         tcg_out8(s, 0x66);
-        tcg_out_modrm_offset(s, 0x89, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x89, data_reg, r0, GUEST_BASE);
         break;
     case 2:
         if (bswap) {
@@ -828,21 +832,21 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
             data_reg = r1;
         }
         /* movl */
-        tcg_out_modrm_offset(s, 0x89, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x89, data_reg, r0, GUEST_BASE);
         break;
     case 3:
         if (bswap) {
             tcg_out_mov(s, r1, data_reg2);
             /* bswap data_reg */
             tcg_out_opc(s, (0xc8 + r1) | P_EXT);
-            tcg_out_modrm_offset(s, 0x89, r1, r0, 0);
+            tcg_out_modrm_offset(s, 0x89, r1, r0, GUEST_BASE);
             tcg_out_mov(s, r1, data_reg);
             /* bswap data_reg */
             tcg_out_opc(s, (0xc8 + r1) | P_EXT);
-            tcg_out_modrm_offset(s, 0x89, r1, r0, 4);
+            tcg_out_modrm_offset(s, 0x89, r1, r0, GUEST_BASE + 4);
         } else {
-            tcg_out_modrm_offset(s, 0x89, data_reg, r0, 0);
-            tcg_out_modrm_offset(s, 0x89, data_reg2, r0, 4);
+            tcg_out_modrm_offset(s, 0x89, data_reg, r0, GUEST_BASE);
+            tcg_out_modrm_offset(s, 0x89, data_reg2, r0, GUEST_BASE + 4);
         }
         break;
     default:
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 301a5bf..461ef31 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -53,6 +53,8 @@ enum {
 #define TCG_TARGET_HAS_ext16s_i32
 #define TCG_TARGET_HAS_rot_i32
 
+#define TCG_TARGET_HAS_GUEST_BASE
+
 /* Note: must be synced with dyngen-exec.h */
 #define TCG_AREG0 TCG_REG_EBP
 #define TCG_AREG1 TCG_REG_EBX