KVM: x86 emulator: allow loading null SS in long mode

Null SS is valid in long mode; allow loading it.

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2012-06-07 17:03:42 +03:00
parent 6d6eede4a0
commit 79d5b4c3cd
1 changed files with 8 additions and 4 deletions

View File

@ -1324,8 +1324,14 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
goto load;
}
/* NULL selector is not valid for TR, CS and SS */
if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR)
rpl = selector & 3;
cpl = ctxt->ops->cpl(ctxt);
/* NULL selector is not valid for TR, CS and SS (except for long mode) */
if ((seg == VCPU_SREG_CS
|| (seg == VCPU_SREG_SS
&& (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl))
|| seg == VCPU_SREG_TR)
&& null_selector)
goto exception;
@ -1352,9 +1358,7 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
goto exception;
}
rpl = selector & 3;
dpl = seg_desc.dpl;
cpl = ctxt->ops->cpl(ctxt);
switch (seg) {
case VCPU_SREG_SS: