diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 81b0f8848960..83ded7c03d12 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2175,6 +2175,45 @@ static int em_push(struct x86_emulate_ctxt *ctxt) return X86EMUL_CONTINUE; } +static int em_das(struct x86_emulate_ctxt *ctxt) +{ + struct decode_cache *c = &ctxt->decode; + u8 al, old_al; + bool af, cf, old_cf; + + cf = ctxt->eflags & X86_EFLAGS_CF; + al = c->dst.val; + + old_al = al; + old_cf = cf; + cf = false; + af = ctxt->eflags & X86_EFLAGS_AF; + if ((al & 0x0f) > 9 || af) { + al -= 6; + cf = old_cf | (al >= 250); + af = true; + } else { + af = false; + } + if (old_al > 0x99 || old_cf) { + al -= 0x60; + cf = true; + } + + c->dst.val = al; + /* Set PF, ZF, SF */ + c->src.type = OP_IMM; + c->src.val = 0; + c->src.bytes = 1; + emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags); + ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF); + if (cf) + ctxt->eflags |= X86_EFLAGS_CF; + if (af) + ctxt->eflags |= X86_EFLAGS_AF; + return X86EMUL_CONTINUE; +} + #define D(_y) { .flags = (_y) } #define N D(0) #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) } @@ -2258,7 +2297,8 @@ static struct opcode opcode_table[256] = { /* 0x28 - 0x2F */ D(ByteOp | DstMem | SrcReg | ModRM | Lock), D(DstMem | SrcReg | ModRM | Lock), D(ByteOp | DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM), - D(ByteOp | DstAcc | SrcImmByte), D(DstAcc | SrcImm), N, N, + D(ByteOp | DstAcc | SrcImmByte), D(DstAcc | SrcImm), + N, I(ByteOp | DstAcc | No64, em_das), /* 0x30 - 0x37 */ D(ByteOp | DstMem | SrcReg | ModRM | Lock), D(DstMem | SrcReg | ModRM | Lock), D(ByteOp | DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM), |