From c9eaf20f268c7051bfde2ba212c5ea76a6cbc7a1 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 18 May 2009 16:13:45 +0300 Subject: [PATCH] KVM: x86 emulator: Implement zero-extended immediate decoding Absolute jumps use zero extended immediate operands. Cc: stable@kernel.org Signed-off-by: Avi Kivity --- arch/x86/kvm/x86_emulate.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c index 616de4628d60..a30d5fc17eef 100644 --- a/arch/x86/kvm/x86_emulate.c +++ b/arch/x86/kvm/x86_emulate.c @@ -60,6 +60,7 @@ #define SrcImmByte (6<<4) /* 8-bit sign-extended immediate operand. */ #define SrcOne (7<<4) /* Implied '1' */ #define SrcImmUByte (8<<4) /* 8-bit unsigned immediate operand. */ +#define SrcImmU (9<<4) /* Immediate operand, unsigned */ #define SrcMask (0xf<<4) /* Generic ModRM decode. */ #define ModRM (1<<8) @@ -1027,6 +1028,7 @@ done_prefixes: c->src.type = OP_MEM; break; case SrcImm: + case SrcImmU: c->src.type = OP_IMM; c->src.ptr = (unsigned long *)c->eip; c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; @@ -1044,6 +1046,19 @@ done_prefixes: c->src.val = insn_fetch(s32, 4, c->eip); break; } + if ((c->d & SrcMask) == SrcImmU) { + switch (c->src.bytes) { + case 1: + c->src.val &= 0xff; + break; + case 2: + c->src.val &= 0xffff; + break; + case 4: + c->src.val &= 0xffffffff; + break; + } + } break; case SrcImmByte: case SrcImmUByte: