diff options
| author | Avi Kivity <avi@qumranet.com> | 2008-06-15 22:09:11 -0700 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-07-20 12:42:34 +0300 |
| commit | f5b4edcd52e78556800f90d08bfc9126416ac82f (patch) | |
| tree | 5c40b9781cf18d66c9e71b837ffc3eaddac48ddb /arch/x86 | |
| parent | 84411d85dacdb6665578608c6a70fc8b819761a8 (diff) | |
KVM: x86 emulator: simplify rip relative decoding
rip relative decoding is relative to the instruction pointer of the next
instruction; by moving address adjustment until after decoding is complete,
we remove the need to determine the instruction size.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/x86_emulate.c | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c index c3a823174f3..20b604489c3 100644 --- a/arch/x86/kvm/x86_emulate.c +++ b/arch/x86/kvm/x86_emulate.c @@ -664,7 +664,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, { struct decode_cache *c = &ctxt->decode; u8 sib; - int index_reg = 0, base_reg = 0, scale, rip_relative = 0; + int index_reg = 0, base_reg = 0, scale; int rc = 0; if (c->rex_prefix) { @@ -754,7 +754,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, c->modrm_ea += c->regs[index_reg] << scale; } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) { if (ctxt->mode == X86EMUL_MODE_PROT64) - rip_relative = 1; + c->rip_relative = 1; } else c->modrm_ea += c->regs[c->modrm_rm]; switch (c->modrm_mod) { @@ -770,22 +770,6 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, break; } } - if (rip_relative) { - c->modrm_ea += c->eip; - switch (c->d & SrcMask) { - case SrcImmByte: - c->modrm_ea += 1; - break; - case SrcImm: - if (c->d & ByteOp) - c->modrm_ea += 1; - else - if (c->op_bytes == 8) - c->modrm_ea += 4; - else - c->modrm_ea += c->op_bytes; - } - } done: return rc; } @@ -1044,6 +1028,9 @@ done_prefixes: break; } + if (c->rip_relative) + c->modrm_ea += c->eip; + done: return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; } |