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Subject[PATCH 06/48] KVM: x86 emulator: Implement zero-extended immediate decoding
Date
Absolute jumps use zero extended immediate operands.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/x86_emulate.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index 616de46..a30d5fc 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:
--
1.6.3.3


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