KVM: x86 emulator: remove _eflags and use directly ctxt->eflags.

Remove _eflags and use directly ctxt->eflags. Caching eflags is not needed as
it is restored to vcpu by kvm_main.c:emulate_instruction() from ctxt->eflags
only if emulation doesn't fail.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 59 insertions, 62 deletions

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index a15609279283..76b813b6365c 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -941,37 +941,37 @@ static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt,
         return 0;
 }
 
-static inline void emulate_grp2(struct decode_cache *c, unsigned long *_eflags)
+static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt)
 {
+        struct decode_cache *c = &ctxt->decode;
         switch (c->modrm_reg) {
         case 0: /* rol */
-                emulate_2op_SrcB("rol", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags);
                 break;
         case 1: /* ror */
-                emulate_2op_SrcB("ror", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags);
                 break;
         case 2: /* rcl */
-                emulate_2op_SrcB("rcl", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags);
                 break;
         case 3: /* rcr */
-                emulate_2op_SrcB("rcr", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags);
                 break;
         case 4: /* sal/shl */
         case 6: /* sal/shl */
-                emulate_2op_SrcB("sal", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags);
                 break;
         case 5: /* shr */
-                emulate_2op_SrcB("shr", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags);
                 break;
         case 7: /* sar */
-                emulate_2op_SrcB("sar", c->src, c->dst, *_eflags);
+                emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags);
                 break;
         }
 }
 
 static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
-                               struct x86_emulate_ops *ops,
-                               unsigned long *_eflags)
+                               struct x86_emulate_ops *ops)
 {
         struct decode_cache *c = &ctxt->decode;
         int rc = 0;
@@ -998,13 +998,13 @@ static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
                         c->src.val = insn_fetch(s32, 4, c->eip);
                         break;
                 }
-                emulate_2op_SrcV("test", c->src, c->dst, *_eflags);
+                emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
                 break;
         case 2: /* not */
                 c->dst.val = ~c->dst.val;
                 break;
         case 3: /* neg */
-                emulate_1op("neg", c->dst, *_eflags);
+                emulate_1op("neg", c->dst, ctxt->eflags);
                 break;
         default:
                 DPRINTF("Cannot emulate %02x\n", c->b);
@@ -1017,7 +1017,6 @@ done:
 
 static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
                                struct x86_emulate_ops *ops,
-                               unsigned long *_eflags,
                                int *no_wb)
 {
         struct decode_cache *c = &ctxt->decode;
@@ -1025,10 +1024,10 @@ static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
 
         switch (c->modrm_reg) {
         case 0: /* inc */
-                emulate_1op("inc", c->dst, *_eflags);
+                emulate_1op("inc", c->dst, ctxt->eflags);
                 break;
         case 1: /* dec */
-                emulate_1op("dec", c->dst, *_eflags);
+                emulate_1op("dec", c->dst, ctxt->eflags);
                 break;
         case 4: /* jmp abs */
                 if (c->b == 0xff)
@@ -1067,7 +1066,6 @@ static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
 
 static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
                                struct x86_emulate_ops *ops,
-                               unsigned long *_eflags,
                                unsigned long cr2)
 {
         struct decode_cache *c = &ctxt->decode;
@@ -1083,7 +1081,7 @@ static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
 
                 c->regs[VCPU_REGS_RAX] = (u32) (old >> 0);
                 c->regs[VCPU_REGS_RDX] = (u32) (old >> 32);
-                *_eflags &= ~EFLG_ZF;
+                ctxt->eflags &= ~EFLG_ZF;
 
         } else {
                 new = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
@@ -1092,7 +1090,7 @@ static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
                 rc = ops->cmpxchg_emulated(cr2, &old, &new, 8, ctxt->vcpu);
                 if (rc != 0)
                         return rc;
-                *_eflags |= EFLG_ZF;
+                ctxt->eflags |= EFLG_ZF;
         }
         return 0;
 }
@@ -1152,7 +1150,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
         int no_wb = 0;
         u64 msr_data;
         unsigned long saved_eip = 0;
-        unsigned long _eflags = ctxt->eflags;
         struct decode_cache *c = &ctxt->decode;
         int rc = 0;
 
@@ -1207,23 +1204,23 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
         switch (c->b) {
         case 0x00 ... 0x05:
               add:              /* add */
-                emulate_2op_SrcV("add", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x08 ... 0x0d:
               or:               /* or */
-                emulate_2op_SrcV("or", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x10 ... 0x15:
               adc:              /* adc */
-                emulate_2op_SrcV("adc", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x18 ... 0x1d:
               sbb:              /* sbb */
-                emulate_2op_SrcV("sbb", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x20 ... 0x23:
               and:              /* and */
-                emulate_2op_SrcV("and", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x24:              /* and al imm8 */
                 c->dst.type = OP_REG;
@@ -1244,15 +1241,15 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                 goto and;
         case 0x28 ... 0x2d:
               sub:              /* sub */
-                emulate_2op_SrcV("sub", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x30 ... 0x35:
               xor:              /* xor */
-                emulate_2op_SrcV("xor", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x38 ... 0x3d:
               cmp:              /* cmp */
-                emulate_2op_SrcV("cmp", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x63:              /* movsxd */
                 if (ctxt->mode != X86EMUL_MODE_PROT64)
@@ -1280,7 +1277,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                 }
                 break;
         case 0x84 ... 0x85:
-                emulate_2op_SrcV("test", c->src, c->dst, _eflags);
+                emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
                 break;
         case 0x86 ... 0x87:     /* xchg */
                 /* Write back the register source. */
@@ -1327,7 +1324,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                 c->eip += c->ad_bytes;
                 break;
         case 0xc0 ... 0xc1:
-                emulate_grp2(c, &_eflags);
+                emulate_grp2(ctxt);
                 break;
         case 0xc6 ... 0xc7:     /* mov (sole member of Grp11) */
         mov:
@@ -1335,19 +1332,19 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                 break;
         case 0xd0 ... 0xd1:     /* Grp2 */
                 c->src.val = 1;
-                emulate_grp2(c, &_eflags);
+                emulate_grp2(ctxt);
                 break;
         case 0xd2 ... 0xd3:     /* Grp2 */
                 c->src.val = c->regs[VCPU_REGS_RCX];
-                emulate_grp2(c, &_eflags);
+                emulate_grp2(ctxt);
                 break;
         case 0xf6 ... 0xf7:     /* Grp3 */
-                rc = emulate_grp3(ctxt, ops, &_eflags);
+                rc = emulate_grp3(ctxt, ops);
                 if (rc != 0)
                         goto done;
                 break;
         case 0xfe ... 0xff:     /* Grp4/Grp5 */
-                rc = emulate_grp45(ctxt, ops, &_eflags, &no_wb);
+                rc = emulate_grp45(ctxt, ops, &no_wb);
                 if (rc != 0)
                         goto done;
                 break;
@@ -1362,7 +1359,6 @@ writeback:
 
         /* Commit shadow register state. */
         memcpy(ctxt->vcpu->regs, c->regs, sizeof c->regs);
-        ctxt->eflags = _eflags;
         ctxt->vcpu->rip = c->eip;
 
 done:
@@ -1413,7 +1409,7 @@ special_insn:
                                 (c->d & ByteOp) ? 1 : c->op_bytes,
                                 c->rep_prefix ?
                                 address_mask(c->regs[VCPU_REGS_RCX]) : 1,
-                                (_eflags & EFLG_DF),
+                                (ctxt->eflags & EFLG_DF),
                                 register_address(ctxt->es_base,
                                                  c->regs[VCPU_REGS_RDI]),
                                 c->rep_prefix,
@@ -1429,7 +1425,7 @@ special_insn:
                                 (c->d & ByteOp) ? 1 : c->op_bytes,
                                 c->rep_prefix ?
                                 address_mask(c->regs[VCPU_REGS_RCX]) : 1,
-                                (_eflags & EFLG_DF),
+                                (ctxt->eflags & EFLG_DF),
                                 register_address(c->override_base ?
                                                         *c->override_base :
                                                         ctxt->ds_base,
@@ -1443,16 +1439,16 @@ special_insn:
         case 0x70 ... 0x7f: /* jcc (short) */ {
                 int rel = insn_fetch(s8, 1, c->eip);
 
-                if (test_cc(c->b, _eflags))
+                if (test_cc(c->b, ctxt->eflags))
                 JMP_REL(rel);
                 break;
         }
         case 0x9c: /* pushf */
-                c->src.val =  (unsigned long) _eflags;
+                c->src.val =  (unsigned long) ctxt->eflags;
                 emulate_push(ctxt);
                 break;
         case 0x9d: /* popf */
-                c->dst.ptr = (unsigned long *) &_eflags;
+                c->dst.ptr = (unsigned long *) &ctxt->eflags;
                 goto pop_instruction;
         case 0xc3: /* ret */
                 c->dst.ptr = &c->eip;
@@ -1484,10 +1480,10 @@ special_insn:
                                         c->dst.bytes, ctxt->vcpu)) != 0)
                         goto done;
                 register_address_increment(c->regs[VCPU_REGS_RSI],
-                                       (_eflags & EFLG_DF) ? -c->dst.bytes
+                                       (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
                                                            : c->dst.bytes);
                 register_address_increment(c->regs[VCPU_REGS_RDI],
-                                       (_eflags & EFLG_DF) ? -c->dst.bytes
+                                       (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
                                                            : c->dst.bytes);
                 break;
         case 0xa6 ... 0xa7:     /* cmps */
@@ -1499,7 +1495,7 @@ special_insn:
                 c->dst.ptr = (unsigned long *)cr2;
                 c->dst.val = c->regs[VCPU_REGS_RAX];
                 register_address_increment(c->regs[VCPU_REGS_RDI],
-                                       (_eflags & EFLG_DF) ? -c->dst.bytes
+                                       (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
                                                            : c->dst.bytes);
                 break;
         case 0xac ... 0xad:     /* lods */
@@ -1511,7 +1507,7 @@ special_insn:
                                              ctxt->vcpu)) != 0)
                         goto done;
                 register_address_increment(c->regs[VCPU_REGS_RSI],
-                                       (_eflags & EFLG_DF) ? -c->dst.bytes
+                                       (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
                                                            : c->dst.bytes);
                 break;
         case 0xae ... 0xaf:     /* scas */
@@ -1599,7 +1595,8 @@ twobyte_insn:
                 case 6: /* lmsw */
                         if (c->modrm_mod != 3)
                                 goto cannot_emulate;
-                        realmode_lmsw(ctxt->vcpu, (u16)c->modrm_val, &_eflags);
+                        realmode_lmsw(ctxt->vcpu, (u16)c->modrm_val,
+                                                  &ctxt->eflags);
                         break;
                 case 7: /* invlpg*/
                         emulate_invlpg(ctxt->vcpu, cr2);
@@ -1630,29 +1627,29 @@ twobyte_insn:
                  */
                 switch ((c->b & 15) >> 1) {
                 case 0: /* cmovo */
-                        no_wb = (_eflags & EFLG_OF) ? 0 : 1;
+                        no_wb = (ctxt->eflags & EFLG_OF) ? 0 : 1;
                         break;
                 case 1: /* cmovb/cmovc/cmovnae */
-                        no_wb = (_eflags & EFLG_CF) ? 0 : 1;
+                        no_wb = (ctxt->eflags & EFLG_CF) ? 0 : 1;
                         break;
                 case 2: /* cmovz/cmove */
-                        no_wb = (_eflags & EFLG_ZF) ? 0 : 1;
+                        no_wb = (ctxt->eflags & EFLG_ZF) ? 0 : 1;
                         break;
                 case 3: /* cmovbe/cmovna */
-                        no_wb = (_eflags & (EFLG_CF | EFLG_ZF)) ? 0 : 1;
+                        no_wb = (ctxt->eflags & (EFLG_CF | EFLG_ZF)) ? 0 : 1;
                         break;
                 case 4: /* cmovs */
-                        no_wb = (_eflags & EFLG_SF) ? 0 : 1;
+                        no_wb = (ctxt->eflags & EFLG_SF) ? 0 : 1;
                         break;
                 case 5: /* cmovp/cmovpe */
-                        no_wb = (_eflags & EFLG_PF) ? 0 : 1;
+                        no_wb = (ctxt->eflags & EFLG_PF) ? 0 : 1;
                         break;
                 case 7: /* cmovle/cmovng */
-                        no_wb = (_eflags & EFLG_ZF) ? 0 : 1;
+                        no_wb = (ctxt->eflags & EFLG_ZF) ? 0 : 1;
                         /* fall through */
                 case 6: /* cmovl/cmovnge */
-                        no_wb &= (!(_eflags & EFLG_SF) !=
-                              !(_eflags & EFLG_OF)) ? 0 : 1;
+                        no_wb &= (!(ctxt->eflags & EFLG_SF) !=
+                              !(ctxt->eflags & EFLG_OF)) ? 0 : 1;
                         break;
                 }
                 /* Odd cmov opcodes (lsb == 1) have inverted sense. */
@@ -1662,13 +1659,13 @@ twobyte_insn:
               bt:               /* bt */
                 /* only subword offset */
                 c->src.val &= (c->dst.bytes << 3) - 1;
-                emulate_2op_SrcV_nobyte("bt", c->src, c->dst, _eflags);
+                emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags);
                 break;
         case 0xab:
               bts:              /* bts */
                 /* only subword offset */
                 c->src.val &= (c->dst.bytes << 3) - 1;
-                emulate_2op_SrcV_nobyte("bts", c->src, c->dst, _eflags);
+                emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags);
                 break;
         case 0xb0 ... 0xb1:     /* cmpxchg */
                 /*
@@ -1677,8 +1674,8 @@ twobyte_insn:
                  */
                 c->src.orig_val = c->src.val;
                 c->src.val = c->regs[VCPU_REGS_RAX];
-                emulate_2op_SrcV("cmp", c->src, c->dst, _eflags);
-                if (_eflags & EFLG_ZF) {
+                emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
+                if (ctxt->eflags & EFLG_ZF) {
                         /* Success: write back to memory. */
                         c->dst.val = c->src.orig_val;
                 } else {
@@ -1691,7 +1688,7 @@ twobyte_insn:
               btr:              /* btr */
                 /* only subword offset */
                 c->src.val &= (c->dst.bytes << 3) - 1;
-                emulate_2op_SrcV_nobyte("btr", c->src, c->dst, _eflags);
+                emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags);
                 break;
         case 0xb6 ... 0xb7:     /* movzx */
                 c->dst.bytes = c->op_bytes;
@@ -1714,7 +1711,7 @@ twobyte_insn:
               btc:              /* btc */
                 /* only subword offset */
                 c->src.val &= (c->dst.bytes << 3) - 1;
-                emulate_2op_SrcV_nobyte("btc", c->src, c->dst, _eflags);
+                emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
                 break;
         case 0xbe ... 0xbf:     /* movsx */
                 c->dst.bytes = c->op_bytes;
@@ -1753,7 +1750,7 @@ twobyte_special_insn:
                 if (c->modrm_mod != 3)
                         goto cannot_emulate;
                 realmode_set_cr(ctxt->vcpu,
-                                c->modrm_reg, c->modrm_val, &_eflags);
+                                c->modrm_reg, c->modrm_val, &ctxt->eflags);
                 break;
         case 0x30:
                 /* wrmsr */
@@ -1795,12 +1792,12 @@ twobyte_special_insn:
                         DPRINTF("jnz: Invalid op_bytes\n");
                         goto cannot_emulate;
                 }
-                if (test_cc(c->b, _eflags))
+                if (test_cc(c->b, ctxt->eflags))
                         JMP_REL(rel);
                 break;
         }
         case 0xc7:              /* Grp9 (cmpxchg8b) */
-                rc = emulate_grp9(ctxt, ops, &_eflags, cr2);
+                rc = emulate_grp9(ctxt, ops, cr2);
                 if (rc != 0)
                         goto done;
                 break;