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KVM: x86 emulator: Implement zero-extended immediate decoding

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Absolute jumps use zero extended immediate operands.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2009-05-18 16:13:45 +03:00
parent cb007648de
commit c9eaf20f26
1 changed files with 15 additions and 0 deletions
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15
arch/x86/kvm/x86_emulate.c
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@ -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: