diff options
| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-04-18 03:35:10 +0300 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2014-04-23 17:46:59 -0300 |
| commit | e6e39f0438bc4b0da9334ca42337775c7a00db21 (patch) | |
| tree | f45f3cd73bf5dfed71656891368654f3cc6c9bab /arch/x86/kvm | |
| parent | 346874c9507a2582d0c00021f848de6e115f276c (diff) | |
KVM: x86: IN instruction emulation should ignore REP-prefix
The IN instruction is not be affected by REP-prefix as INS is. Therefore, the
emulation should ignore the REP prefix as well. The current emulator
implementation tries to perform writeback when IN instruction with REP-prefix
is emulated. This causes it to perform wrong memory write or spurious #GP
exception to be injected to the guest.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index f3834bbca1d7..e8a58409b5ac 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1324,7 +1324,8 @@ static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, rc->end = n * size; } - if (ctxt->rep_prefix && !(ctxt->eflags & EFLG_DF)) { + if (ctxt->rep_prefix && (ctxt->d & String) && + !(ctxt->eflags & EFLG_DF)) { ctxt->dst.data = rc->data + rc->pos; ctxt->dst.type = OP_MEM_STR; ctxt->dst.count = (rc->end - rc->pos) / size; |