diff options
author | Richard Henderson <rth@twiddle.net> | 2012-10-22 12:11:07 +1000 |
---|---|---|
committer | Aurelien Jarno <aurelien@aurel32.net> | 2012-10-28 14:54:25 +0100 |
commit | 44b37ace0636cd229e956c5000a1bb6a49e274e7 (patch) | |
tree | fb3771e520836d2b1ead8807a26a13acbbe5ccf7 /tcg/i386 | |
parent | d73ee8a2b5267adae41ecb464cae06a185d2b0f9 (diff) |
tcg-i386: Use %gs prefixes for x86_64 GUEST_BASE
When we allocate a reserved_va for the guest, the kernel will likely
choose an address well above 4G. At which point we must use a pair
of movabsq+addq to form the host address. If we have OS support,
set up a segment register to point to guest_base instead.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'tcg/i386')
-rw-r--r-- | tcg/i386/tcg-target.c | 153 |
1 files changed, 97 insertions, 56 deletions
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c index 9c8f69ae6b..e45a5a0426 100644 --- a/tcg/i386/tcg-target.c +++ b/tcg/i386/tcg-target.c @@ -232,11 +232,13 @@ static inline int tcg_target_const_match(tcg_target_long val, # define P_REXW 0x800 /* Set REX.W = 1 */ # define P_REXB_R 0x1000 /* REG field as byte register */ # define P_REXB_RM 0x2000 /* R/M field as byte register */ +# define P_GS 0x4000 /* gs segment override */ #else # define P_ADDR32 0 # define P_REXW 0 # define P_REXB_R 0 # define P_REXB_RM 0 +# define P_GS 0 #endif #define OPC_ARITH_EvIz (0x81) @@ -352,6 +354,9 @@ static void tcg_out_opc(TCGContext *s, int opc, int r, int rm, int x) { int rex; + if (opc & P_GS) { + tcg_out8(s, 0x65); + } if (opc & P_DATA16) { /* We should never be asking for both 16 and 64-bit operation. */ assert((opc & P_REXW) == 0); @@ -1076,10 +1081,27 @@ static inline void tcg_out_tlb_load(TCGContext *s, int addrlo_idx, tcg_out_modrm_offset(s, OPC_ADD_GvEv + P_REXW, r1, r0, offsetof(CPUTLBEntry, addend) - which); } -#endif +#elif defined(__x86_64__) && defined(__linux__) +# include <asm/prctl.h> +# include <sys/prctl.h> + +int arch_prctl(int code, unsigned long addr); + +static int guest_base_flags; +static inline void setup_guest_base_seg(void) +{ + if (arch_prctl(ARCH_SET_GS, GUEST_BASE) == 0) { + guest_base_flags = P_GS; + } +} +#else +# define guest_base_flags 0 +static inline void setup_guest_base_seg(void) { } +#endif /* SOFTMMU */ static void tcg_out_qemu_ld_direct(TCGContext *s, int datalo, int datahi, - int base, tcg_target_long ofs, int sizeop) + int base, tcg_target_long ofs, int seg, + int sizeop) { #ifdef TARGET_WORDS_BIGENDIAN const int bswap = 1; @@ -1088,28 +1110,29 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, int datalo, int datahi, #endif switch (sizeop) { case 0: - tcg_out_modrm_offset(s, OPC_MOVZBL, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVZBL + seg, datalo, base, ofs); break; case 0 | 4: - tcg_out_modrm_offset(s, OPC_MOVSBL + P_REXW, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVSBL + P_REXW + seg, datalo, base, ofs); break; case 1: - tcg_out_modrm_offset(s, OPC_MOVZWL, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVZWL + seg, datalo, base, ofs); if (bswap) { tcg_out_rolw_8(s, datalo); } break; case 1 | 4: if (bswap) { - tcg_out_modrm_offset(s, OPC_MOVZWL, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVZWL + seg, datalo, base, ofs); tcg_out_rolw_8(s, datalo); tcg_out_modrm(s, OPC_MOVSWL + P_REXW, datalo, datalo); } else { - tcg_out_modrm_offset(s, OPC_MOVSWL + P_REXW, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVSWL + P_REXW + seg, + datalo, base, ofs); } break; case 2: - tcg_out_ld(s, TCG_TYPE_I32, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, datalo, base, ofs); if (bswap) { tcg_out_bswap32(s, datalo); } @@ -1117,17 +1140,18 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, int datalo, int datahi, #if TCG_TARGET_REG_BITS == 64 case 2 | 4: if (bswap) { - tcg_out_ld(s, TCG_TYPE_I32, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, datalo, base, ofs); tcg_out_bswap32(s, datalo); tcg_out_ext32s(s, datalo, datalo); } else { - tcg_out_modrm_offset(s, OPC_MOVSLQ, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVSLQ + seg, datalo, base, ofs); } break; #endif case 3: if (TCG_TARGET_REG_BITS == 64) { - tcg_out_ld(s, TCG_TYPE_I64, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + P_REXW + seg, + datalo, base, ofs); if (bswap) { tcg_out_bswap64(s, datalo); } @@ -1138,11 +1162,15 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, int datalo, int datahi, datahi = t; } if (base != datalo) { - tcg_out_ld(s, TCG_TYPE_I32, datalo, base, ofs); - tcg_out_ld(s, TCG_TYPE_I32, datahi, base, ofs + 4); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, + datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, + datahi, base, ofs + 4); } else { - tcg_out_ld(s, TCG_TYPE_I32, datahi, base, ofs + 4); - tcg_out_ld(s, TCG_TYPE_I32, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, + datahi, base, ofs + 4); + tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, + datalo, base, ofs); } if (bswap) { tcg_out_bswap32(s, datalo); @@ -1186,7 +1214,7 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, label_ptr, offsetof(CPUTLBEntry, addr_read)); /* TLB Hit. */ - tcg_out_qemu_ld_direct(s, data_reg, data_reg2, TCG_REG_L1, 0, opc); + tcg_out_qemu_ld_direct(s, data_reg, data_reg2, TCG_REG_L1, 0, 0, opc); /* jmp label2 */ tcg_out8(s, OPC_JMP_short); @@ -1273,29 +1301,31 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, { int32_t offset = GUEST_BASE; int base = args[addrlo_idx]; - - if (TCG_TARGET_REG_BITS == 64) { - /* ??? We assume all operations have left us with register - contents that are zero extended. So far this appears to - be true. If we want to enforce this, we can either do - an explicit zero-extension here, or (if GUEST_BASE == 0) - use the ADDR32 prefix. For now, do nothing. */ - - if (offset != GUEST_BASE) { - tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, GUEST_BASE); - tgen_arithr(s, ARITH_ADD + P_REXW, TCG_REG_L1, base); - base = TCG_REG_L1; - offset = 0; - } + int seg = 0; + + /* ??? We assume all operations have left us with register contents + that are zero extended. So far this appears to be true. If we + want to enforce this, we can either do an explicit zero-extension + here, or (if GUEST_BASE == 0, or a segment register is in use) + use the ADDR32 prefix. For now, do nothing. */ + if (GUEST_BASE && guest_base_flags) { + seg = guest_base_flags; + offset = 0; + } else if (TCG_TARGET_REG_BITS == 64 && offset != GUEST_BASE) { + tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, GUEST_BASE); + tgen_arithr(s, ARITH_ADD + P_REXW, TCG_REG_L1, base); + base = TCG_REG_L1; + offset = 0; } - tcg_out_qemu_ld_direct(s, data_reg, data_reg2, base, offset, opc); + tcg_out_qemu_ld_direct(s, data_reg, data_reg2, base, offset, seg, opc); } #endif } static void tcg_out_qemu_st_direct(TCGContext *s, int datalo, int datahi, - int base, tcg_target_long ofs, int sizeop) + int base, tcg_target_long ofs, int seg, + int sizeop) { #ifdef TARGET_WORDS_BIGENDIAN const int bswap = 1; @@ -1310,7 +1340,8 @@ static void tcg_out_qemu_st_direct(TCGContext *s, int datalo, int datahi, switch (sizeop) { case 0: - tcg_out_modrm_offset(s, OPC_MOVB_EvGv + P_REXB_R, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVB_EvGv + P_REXB_R + seg, + datalo, base, ofs); break; case 1: if (bswap) { @@ -1318,7 +1349,8 @@ static void tcg_out_qemu_st_direct(TCGContext *s, int datalo, int datahi, tcg_out_rolw_8(s, scratch); datalo = scratch; } - tcg_out_modrm_offset(s, OPC_MOVL_EvGv + P_DATA16, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + P_DATA16 + seg, + datalo, base, ofs); break; case 2: if (bswap) { @@ -1326,7 +1358,7 @@ static void tcg_out_qemu_st_direct(TCGContext *s, int datalo, int datahi, tcg_out_bswap32(s, scratch); datalo = scratch; } - tcg_out_st(s, TCG_TYPE_I32, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, datalo, base, ofs); break; case 3: if (TCG_TARGET_REG_BITS == 64) { @@ -1335,17 +1367,18 @@ static void tcg_out_qemu_st_direct(TCGContext *s, int datalo, int datahi, tcg_out_bswap64(s, scratch); datalo = scratch; } - tcg_out_st(s, TCG_TYPE_I64, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + P_REXW + seg, + datalo, base, ofs); } else if (bswap) { tcg_out_mov(s, TCG_TYPE_I32, scratch, datahi); tcg_out_bswap32(s, scratch); - tcg_out_st(s, TCG_TYPE_I32, scratch, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, scratch, base, ofs); tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo); tcg_out_bswap32(s, scratch); - tcg_out_st(s, TCG_TYPE_I32, scratch, base, ofs + 4); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, scratch, base, ofs+4); } else { - tcg_out_st(s, TCG_TYPE_I32, datalo, base, ofs); - tcg_out_st(s, TCG_TYPE_I32, datahi, base, ofs + 4); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, datalo, base, ofs); + tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, datahi, base, ofs+4); } break; default: @@ -1379,7 +1412,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, label_ptr, offsetof(CPUTLBEntry, addr_write)); /* TLB Hit. */ - tcg_out_qemu_st_direct(s, data_reg, data_reg2, TCG_REG_L1, 0, opc); + tcg_out_qemu_st_direct(s, data_reg, data_reg2, TCG_REG_L1, 0, 0, opc); /* jmp label2 */ tcg_out8(s, OPC_JMP_short); @@ -1436,23 +1469,24 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, { int32_t offset = GUEST_BASE; int base = args[addrlo_idx]; - - if (TCG_TARGET_REG_BITS == 64) { - /* ??? We assume all operations have left us with register - contents that are zero extended. So far this appears to - be true. If we want to enforce this, we can either do - an explicit zero-extension here, or (if GUEST_BASE == 0) - use the ADDR32 prefix. For now, do nothing. */ - - if (offset != GUEST_BASE) { - tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, GUEST_BASE); - tgen_arithr(s, ARITH_ADD + P_REXW, TCG_REG_L1, base); - base = TCG_REG_L1; - offset = 0; - } + int seg = 0; + + /* ??? We assume all operations have left us with register contents + that are zero extended. So far this appears to be true. If we + want to enforce this, we can either do an explicit zero-extension + here, or (if GUEST_BASE == 0, or a segment register is in use) + use the ADDR32 prefix. For now, do nothing. */ + if (GUEST_BASE && guest_base_flags) { + seg = guest_base_flags; + offset = 0; + } else if (TCG_TARGET_REG_BITS == 64 && offset != GUEST_BASE) { + tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, GUEST_BASE); + tgen_arithr(s, ARITH_ADD + P_REXW, TCG_REG_L1, base); + base = TCG_REG_L1; + offset = 0; } - tcg_out_qemu_st_direct(s, data_reg, data_reg2, base, offset, opc); + tcg_out_qemu_st_direct(s, data_reg, data_reg2, base, offset, seg, opc); } #endif } @@ -2046,6 +2080,13 @@ static void tcg_target_qemu_prologue(TCGContext *s) tcg_out_pop(s, tcg_target_callee_save_regs[i]); } tcg_out_opc(s, OPC_RET, 0, 0, 0); + +#if !defined(CONFIG_SOFTMMU) + /* Try to set up a segment register to point to GUEST_BASE. */ + if (GUEST_BASE) { + setup_guest_base_seg(); + } +#endif } static void tcg_target_init(TCGContext *s) |