From 573e80fe04db1aa44e8303037f65716ba5c3a343 Mon Sep 17 00:00:00 2001 From: Bandan Das Date: Wed, 16 Apr 2014 12:46:13 -0400 Subject: [PATCH] KVM: emulate: rework seg_override x86_decode_insn already sets a default for seg_override, so remove it from the zeroed area. Also replace set/get functions with direct access to the field. Signed-off-by: Bandan Das Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_emulate.h | 3 +-- arch/x86/kvm/emulate.c | 41 ++++++++++++------------------ 2 files changed, 17 insertions(+), 27 deletions(-) diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h index d40a10a38a80..6c808408326f 100644 --- a/arch/x86/include/asm/kvm_emulate.h +++ b/arch/x86/include/asm/kvm_emulate.h @@ -295,12 +295,10 @@ struct x86_emulate_ctxt { struct operand dst; int (*execute)(struct x86_emulate_ctxt *ctxt); int (*check_perm)(struct x86_emulate_ctxt *ctxt); - bool has_seg_override; bool rip_relative; u8 rex_prefix; u8 lock_prefix; u8 rep_prefix; - u8 seg_override; /* bitmaps of registers in _regs[] that can be read */ u32 regs_valid; /* bitmaps of registers in _regs[] that have been written */ @@ -311,6 +309,7 @@ struct x86_emulate_ctxt { u8 modrm_reg; u8 modrm_rm; u8 modrm_seg; + u8 seg_override; u64 d; unsigned long _eip; struct operand memop; diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 3e9bbdc4c76a..08badf638fb0 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -514,12 +514,6 @@ static u32 desc_limit_scaled(struct desc_struct *desc) return desc->g ? (limit << 12) | 0xfff : limit; } -static void set_seg_override(struct x86_emulate_ctxt *ctxt, int seg) -{ - ctxt->has_seg_override = true; - ctxt->seg_override = seg; -} - static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) { if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) @@ -528,14 +522,6 @@ static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) return ctxt->ops->get_cached_segment_base(ctxt, seg); } -static unsigned seg_override(struct x86_emulate_ctxt *ctxt) -{ - if (!ctxt->has_seg_override) - return 0; - - return ctxt->seg_override; -} - static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, u32 error, bool valid) { @@ -4169,7 +4155,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSI)); - op->addr.mem.seg = seg_override(ctxt); + op->addr.mem.seg = ctxt->seg_override; op->val = 0; op->count = 1; break; @@ -4180,7 +4166,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, register_address(ctxt, reg_read(ctxt, VCPU_REGS_RBX) + (reg_read(ctxt, VCPU_REGS_RAX) & 0xff)); - op->addr.mem.seg = seg_override(ctxt); + op->addr.mem.seg = ctxt->seg_override; op->val = 0; break; case OpImmFAddr: @@ -4227,6 +4213,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) int mode = ctxt->mode; int def_op_bytes, def_ad_bytes, goffset, simd_prefix; bool op_prefix = false; + bool has_seg_override = false; struct opcode opcode; ctxt->memop.type = OP_NONE; @@ -4280,11 +4267,13 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) case 0x2e: /* CS override */ case 0x36: /* SS override */ case 0x3e: /* DS override */ - set_seg_override(ctxt, (ctxt->b >> 3) & 3); + has_seg_override = true; + ctxt->seg_override = (ctxt->b >> 3) & 3; break; case 0x64: /* FS override */ case 0x65: /* GS override */ - set_seg_override(ctxt, ctxt->b & 7); + has_seg_override = true; + ctxt->seg_override = ctxt->b & 7; break; case 0x40 ... 0x4f: /* REX */ if (mode != X86EMUL_MODE_PROT64) @@ -4422,17 +4411,19 @@ done_prefixes: /* ModRM and SIB bytes. */ if (ctxt->d & ModRM) { rc = decode_modrm(ctxt, &ctxt->memop); - if (!ctxt->has_seg_override) - set_seg_override(ctxt, ctxt->modrm_seg); + if (!has_seg_override) { + has_seg_override = true; + ctxt->seg_override = ctxt->modrm_seg; + } } else if (ctxt->d & MemAbs) rc = decode_abs(ctxt, &ctxt->memop); if (rc != X86EMUL_CONTINUE) goto done; - if (!ctxt->has_seg_override) - set_seg_override(ctxt, VCPU_SREG_DS); + if (!has_seg_override) + ctxt->seg_override = VCPU_SREG_DS; - ctxt->memop.addr.mem.seg = seg_override(ctxt); + ctxt->memop.addr.mem.seg = ctxt->seg_override; if (ctxt->memop.type == OP_MEM && ctxt->ad_bytes != 8) ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea; @@ -4534,8 +4525,8 @@ static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *)) void init_decode_cache(struct x86_emulate_ctxt *ctxt) { - memset(&ctxt->has_seg_override, 0, - (void *)&ctxt->modrm - (void *)&ctxt->has_seg_override); + memset(&ctxt->rip_relative, 0, + (void *)&ctxt->modrm - (void *)&ctxt->rip_relative); ctxt->io_read.pos = 0; ctxt->io_read.end = 0; -- 2.20.1