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>

7 files changed, 103 insertions, 33 deletions

diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c
index 1edcd103f3..6cfe1d6670 100644
--- a/tcg/arm/tcg-target.c
+++ b/tcg/arm/tcg-target.c
@@ -990,7 +990,22 @@ static inline void tcg_out_qemu_ld(TCGContext *s, int cond,
 # endif
 
     *label_ptr += ((void *) s->code_ptr - (void *) label_ptr - 8) >> 2;
-#else
+#else /* !CONFIG_SOFTMMU */
+    if (GUEST_BASE) {
+        uint32_t offset = GUEST_BASE;
+        int i;
+        int rot;
+
+        while (offset) {
+            i = ctz32(offset) & ~1;
+            rot = ((32 - i) << 7) & 0xf00;
+
+            tcg_out_dat_imm(s, COND_AL, ARITH_ADD, 8, addr_reg,
+                            ((offset >> i) & 0xff) | rot);
+            addr_reg = 8;
+            offset &= ~(0xff << i);
+        }
+    }
     switch (opc) {
     case 0:
         tcg_out_ld8_12(s, COND_AL, data_reg, addr_reg, 0);
@@ -1200,7 +1215,22 @@ static inline void tcg_out_qemu_st(TCGContext *s, int cond,
 # endif
 
     *label_ptr += ((void *) s->code_ptr - (void *) label_ptr - 8) >> 2;
-#else
+#else /* !CONFIG_SOFTMMU */
+    if (GUEST_BASE) {
+        uint32_t offset = GUEST_BASE;
+        int i;
+        int rot;
+
+        while (offset) {
+            i = ctz32(offset) & ~1;
+            rot = ((32 - i) << 7) & 0xf00;
+
+            tcg_out_dat_imm(s, COND_AL, ARITH_ADD, 8, addr_reg,
+                            ((offset >> i) & 0xff) | rot);
+            addr_reg = 8;
+            offset &= ~(0xff << i);
+        }
+    }
     switch (opc) {
     case 0:
         tcg_out_st8_12(s, COND_AL, data_reg, addr_reg, 0);
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index 78ab8fd3e5..ffa9ceeca0 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -60,6 +60,8 @@ enum {
 #define TCG_TARGET_STACK_ALIGN		8
 #define TCG_TARGET_CALL_STACK_OFFSET	0
 
+#define TCG_TARGET_HAS_GUEST_BASE
+
 enum {
     /* Note: must be synced with dyngen-exec.h */
     TCG_AREG0 = TCG_REG_R7,
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index e0fd434620..ed61780e67 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 301a5bf142..461ef315c6 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
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 299bff6f03..4cb5934f53 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -46,6 +46,7 @@
 
 #include "qemu-common.h"
 #include "cache-utils.h"
+#include "host-utils.h"
 
 /* Note: the long term plan is to reduce the dependancies on the QEMU
    CPU definitions. Currently they are used for qemu_ld/st
@@ -57,6 +58,9 @@
 #include "tcg-op.h"
 #include "elf.h"
 
+#if defined(CONFIG_USE_GUEST_BASE) && !defined(TCG_TARGET_HAS_GUEST_BASE)
+#error GUEST_BASE not supported on this host.
+#endif
 
 static void patch_reloc(uint8_t *code_ptr, int type, 
                         tcg_target_long value, tcg_target_long addend);
diff --git a/tcg/x86_64/tcg-target.c b/tcg/x86_64/tcg-target.c
index 5378e8510b..9facb01e41 100644
--- a/tcg/x86_64/tcg-target.c
+++ b/tcg/x86_64/tcg-target.c
@@ -508,6 +508,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
                             int opc)
 {
     int addr_reg, data_reg, r0, r1, mem_index, s_bits, bswap, rexw;
+    int32_t offset;
 #if defined(CONFIG_SOFTMMU)
     uint8_t *label1_ptr, *label2_ptr;
 #endif
@@ -604,8 +605,20 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
     /* add x(r1), r0 */
     tcg_out_modrm_offset(s, 0x03 | P_REXW, r0, r1, offsetof(CPUTLBEntry, addend) - 
                          offsetof(CPUTLBEntry, addr_read));
+    offset = 0;
 #else
-    r0 = addr_reg;
+    if (GUEST_BASE == (int32_t)GUEST_BASE) {
+        r0 = addr_reg;
+        offset = GUEST_BASE;
+    } else {
+        offset = 0;
+        /* movq $GUEST_BASE, r0 */
+        tcg_out_opc(s, (0xb8 + (r0 & 7)) | P_REXW, 0, r0, 0);
+        tcg_out32(s, GUEST_BASE);
+        tcg_out32(s, GUEST_BASE >> 32);
+        /* addq addr_reg, r0 */
+        tcg_out_modrm(s, 0x01 | P_REXW, addr_reg, r0);
+    }
 #endif    
 
 #ifdef TARGET_WORDS_BIGENDIAN
@@ -616,15 +629,15 @@ 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, offset);
         break;
     case 0 | 4:
         /* movsbX */
-        tcg_out_modrm_offset(s, 0xbe | P_EXT | rexw, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0xbe | P_EXT | rexw, data_reg, r0, offset);
         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, offset);
         if (bswap) {
             /* rolw $8, data_reg */
             tcg_out8(s, 0x66); 
@@ -635,7 +648,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
     case 1 | 4:
         if (bswap) {
             /* movzwl */
-            tcg_out_modrm_offset(s, 0xb7 | P_EXT, data_reg, r0, 0);
+            tcg_out_modrm_offset(s, 0xb7 | P_EXT, data_reg, r0, offset);
             /* rolw $8, data_reg */
             tcg_out8(s, 0x66); 
             tcg_out_modrm(s, 0xc1, 0, data_reg);
@@ -645,12 +658,12 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
             tcg_out_modrm(s, 0xbf | P_EXT | rexw, data_reg, data_reg);
         } else {
             /* movswX */
-            tcg_out_modrm_offset(s, 0xbf | P_EXT | rexw, data_reg, r0, 0);
+            tcg_out_modrm_offset(s, 0xbf | P_EXT | rexw, data_reg, r0, offset);
         }
         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, offset);
         if (bswap) {
             /* bswap */
             tcg_out_opc(s, (0xc8 + (data_reg & 7)) | P_EXT, 0, data_reg, 0);
@@ -659,19 +672,19 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
     case 2 | 4:
         if (bswap) {
             /* movl (r0), data_reg */
-            tcg_out_modrm_offset(s, 0x8b, data_reg, r0, 0);
+            tcg_out_modrm_offset(s, 0x8b, data_reg, r0, offset);
             /* bswap */
             tcg_out_opc(s, (0xc8 + (data_reg & 7)) | P_EXT, 0, data_reg, 0);
             /* movslq */
             tcg_out_modrm(s, 0x63 | P_REXW, data_reg, data_reg);
         } else {
             /* movslq */
-            tcg_out_modrm_offset(s, 0x63 | P_REXW, data_reg, r0, 0);
+            tcg_out_modrm_offset(s, 0x63 | P_REXW, data_reg, r0, offset);
         }
         break;
     case 3:
         /* movq (r0), data_reg */
-        tcg_out_modrm_offset(s, 0x8b | P_REXW, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x8b | P_REXW, data_reg, r0, offset);
         if (bswap) {
             /* bswap */
             tcg_out_opc(s, (0xc8 + (data_reg & 7)) | P_EXT | P_REXW, 0, data_reg, 0);
@@ -691,6 +704,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
                             int opc)
 {
     int addr_reg, data_reg, r0, r1, mem_index, s_bits, bswap, rexw;
+    int32_t offset;
 #if defined(CONFIG_SOFTMMU)
     uint8_t *label1_ptr, *label2_ptr;
 #endif
@@ -775,8 +789,20 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
     /* add x(r1), r0 */
     tcg_out_modrm_offset(s, 0x03 | P_REXW, r0, r1, offsetof(CPUTLBEntry, addend) - 
                          offsetof(CPUTLBEntry, addr_write));
+    offset = 0;
 #else
-    r0 = addr_reg;
+    if (GUEST_BASE == (int32_t)GUEST_BASE) {
+        r0 = addr_reg;
+        offset = GUEST_BASE;
+    } else {
+        offset = 0;
+        /* movq $GUEST_BASE, r0 */
+        tcg_out_opc(s, (0xb8 + (r0 & 7)) | P_REXW, 0, r0, 0);
+        tcg_out32(s, GUEST_BASE);
+        tcg_out32(s, GUEST_BASE >> 32);
+        /* addq addr_reg, r0 */
+        tcg_out_modrm(s, 0x01 | P_REXW, addr_reg, r0);
+    }
 #endif
 
 #ifdef TARGET_WORDS_BIGENDIAN
@@ -787,7 +813,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
     switch(opc) {
     case 0:
         /* movb */
-        tcg_out_modrm_offset(s, 0x88 | P_REXB, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x88 | P_REXB, data_reg, r0, offset);
         break;
     case 1:
         if (bswap) {
@@ -799,7 +825,7 @@ 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, offset);
         break;
     case 2:
         if (bswap) {
@@ -809,7 +835,7 @@ 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, offset);
         break;
     case 3:
         if (bswap) {
@@ -819,7 +845,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
             data_reg = r1;
         }
         /* movq */
-        tcg_out_modrm_offset(s, 0x89 | P_REXW, data_reg, r0, 0);
+        tcg_out_modrm_offset(s, 0x89 | P_REXW, data_reg, r0, offset);
         break;
     default:
         tcg_abort();
diff --git a/tcg/x86_64/tcg-target.h b/tcg/x86_64/tcg-target.h
index 8cb05c6328..8d47e78738 100644
--- a/tcg/x86_64/tcg-target.h
+++ b/tcg/x86_64/tcg-target.h
@@ -73,6 +73,8 @@ enum {
 #define TCG_TARGET_HAS_rot_i32
 #define TCG_TARGET_HAS_rot_i64
 
+#define TCG_TARGET_HAS_GUEST_BASE
+
 /* Note: must be synced with dyngen-exec.h */
 #define TCG_AREG0 TCG_REG_R14
 #define TCG_AREG1 TCG_REG_R15