Commit cb16c348 authored by Avi Kivity's avatar Avi Kivity

KVM: x86 emulator: fix %rip-relative addressing with immediate source operand

%rip-relative addressing is relative to the first byte of the next instruction,
so we need to add %rip only after we've fetched any immediate bytes.

Based on original patch by Li Xin <xin.li@intel.com>.
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Acked-by: default avatarLi Xin <xin.li@intel.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent b0af8dfd
......@@ -3372,7 +3372,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
bool op_prefix = false;
struct opcode opcode;
struct operand memop = { .type = OP_NONE };
struct operand memop = { .type = OP_NONE }, *memopp = NULL;
c->eip = ctxt->eip;
c->fetch.start = c->eip;
......@@ -3547,9 +3547,6 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
if (memop.type == OP_MEM && c->ad_bytes != 8)
memop.addr.mem.ea = (u32)memop.addr.mem.ea;
if (memop.type == OP_MEM && c->rip_relative)
memop.addr.mem.ea += c->eip;
/*
* Decode and fetch the source operand: register, memory
* or immediate.
......@@ -3571,6 +3568,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
c->op_bytes;
srcmem_common:
c->src = memop;
memopp = &c->src;
break;
case SrcImmU16:
rc = decode_imm(ctxt, &c->src, 2, false);
......@@ -3667,6 +3665,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
case DstMem:
case DstMem64:
c->dst = memop;
memopp = &c->dst;
if ((c->d & DstMask) == DstMem64)
c->dst.bytes = 8;
else
......@@ -3700,10 +3699,13 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
/* Special instructions do their own operand decoding. */
default:
c->dst.type = OP_NONE; /* Disable writeback. */
return 0;
break;
}
done:
if (memopp && memopp->type == OP_MEM && c->rip_relative)
memopp->addr.mem.ea += c->eip;
return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
}
......
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