From 69f55cb11e8d789433d111ac3a0f60be37a1ae01 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 18 Mar 2010 15:20:20 +0200 Subject: [PATCH] KVM: x86 emulator: populate OP_MEM operand during decoding. All struct operand fields are initialized during decoding for all operand types except OP_MEM, but there is no reason for that. Move OP_MEM operand initialization into decoding stage for consistency. Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 66 +++++++++++++++++++----------------------- 1 file changed, 29 insertions(+), 37 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 8225ec26efed..0eed6839619f 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1057,6 +1057,10 @@ done_prefixes: if (c->ad_bytes != 8) c->modrm_ea = (u32)c->modrm_ea; + + if (c->rip_relative) + c->modrm_ea += c->eip; + /* * Decode and fetch the source operand: register, memory * or immediate. @@ -1091,6 +1095,8 @@ done_prefixes: break; } c->src.type = OP_MEM; + c->src.ptr = (unsigned long *)c->modrm_ea; + c->src.val = 0; break; case SrcImm: case SrcImmU: @@ -1169,8 +1175,10 @@ done_prefixes: c->src2.val = 1; break; case Src2Mem16: - c->src2.bytes = 2; c->src2.type = OP_MEM; + c->src2.bytes = 2; + c->src2.ptr = (unsigned long *)(c->modrm_ea + c->src.bytes); + c->src2.val = 0; break; } @@ -1192,6 +1200,15 @@ done_prefixes: break; } c->dst.type = OP_MEM; + c->dst.ptr = (unsigned long *)c->modrm_ea; + c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; + c->dst.val = 0; + if (c->d & BitOp) { + unsigned long mask = ~(c->dst.bytes * 8 - 1); + + c->dst.ptr = (void *)c->dst.ptr + + (c->src.val & mask) / 8; + } break; case DstAcc: c->dst.type = OP_REG; @@ -1215,9 +1232,6 @@ done_prefixes: break; } - if (c->rip_relative) - c->modrm_ea += c->eip; - done: return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; } @@ -1638,14 +1652,13 @@ 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 memop) + struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; u64 old, new; int rc; - rc = ops->read_emulated(memop, &old, 8, ctxt->vcpu); + rc = ops->read_emulated(c->modrm_ea, &old, 8, ctxt->vcpu); if (rc != X86EMUL_CONTINUE) return rc; @@ -1660,7 +1673,7 @@ static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt, new = ((u64)c->regs[VCPU_REGS_RCX] << 32) | (u32) c->regs[VCPU_REGS_RBX]; - rc = ops->cmpxchg_emulated(memop, &old, &new, 8, ctxt->vcpu); + rc = ops->cmpxchg_emulated(c->modrm_ea, &old, &new, 8, ctxt->vcpu); if (rc != X86EMUL_CONTINUE) return rc; ctxt->eflags |= EFLG_ZF; @@ -2382,7 +2395,6 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt, int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { - unsigned long memop = 0; u64 msr_data; unsigned long saved_eip = 0; struct decode_cache *c = &ctxt->decode; @@ -2417,9 +2429,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) goto done; } - if (((c->d & ModRM) && (c->modrm_mod != 3)) || (c->d & MemAbs)) - memop = c->modrm_ea; - if (c->rep_prefix && (c->d & String)) { /* All REP prefixes have the same first termination condition */ if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { @@ -2451,8 +2460,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) } if (c->src.type == OP_MEM) { - c->src.ptr = (unsigned long *)memop; - c->src.val = 0; rc = ops->read_emulated((unsigned long)c->src.ptr, &c->src.val, c->src.bytes, @@ -2463,8 +2470,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) } if (c->src2.type == OP_MEM) { - c->src2.ptr = (unsigned long *)(memop + c->src.bytes); - c->src2.val = 0; rc = ops->read_emulated((unsigned long)c->src2.ptr, &c->src2.val, c->src2.bytes, @@ -2477,25 +2482,12 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) goto special_insn; - if (c->dst.type == OP_MEM) { - c->dst.ptr = (unsigned long *)memop; - c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; - c->dst.val = 0; - if (c->d & BitOp) { - unsigned long mask = ~(c->dst.bytes * 8 - 1); - - c->dst.ptr = (void *)c->dst.ptr + - (c->src.val & mask) / 8; - } - if (!(c->d & Mov)) { - /* optimisation - avoid slow emulated read */ - rc = ops->read_emulated((unsigned long)c->dst.ptr, - &c->dst.val, - c->dst.bytes, - ctxt->vcpu); - if (rc != X86EMUL_CONTINUE) - goto done; - } + if ((c->dst.type == OP_MEM) && !(c->d & Mov)) { + /* optimisation - avoid slow emulated read if Mov */ + rc = ops->read_emulated((unsigned long)c->dst.ptr, &c->dst.val, + c->dst.bytes, ctxt->vcpu); + if (rc != X86EMUL_CONTINUE) + goto done; } c->dst.orig_val = c->dst.val; @@ -3062,7 +3054,7 @@ twobyte_insn: kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; case 7: /* invlpg*/ - emulate_invlpg(ctxt->vcpu, memop); + emulate_invlpg(ctxt->vcpu, c->modrm_ea); /* Disable writeback. */ c->dst.type = OP_NONE; break; @@ -3263,7 +3255,7 @@ twobyte_insn: (u64) c->src.val; break; case 0xc7: /* Grp9 (cmpxchg8b) */ - rc = emulate_grp9(ctxt, ops, memop); + rc = emulate_grp9(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; c->dst.type = OP_NONE; -- 2.39.2