KVM: x86 emulator: Check segment limits in real mode too

Segment limits are verified in real mode, not just protected mode.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index f8b27cd2a6cb..5b1c701cd6d0 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -668,8 +668,6 @@ static int __linearize(struct x86_emulate_ctxt *ctxt,
 
         la = seg_base(ctxt, addr.seg) + addr.ea;
         switch (ctxt->mode) {
-        case X86EMUL_MODE_REAL:
-                break;
         case X86EMUL_MODE_PROT64:
                 if (((signed long)la << 16) >> 16 != la)
                         return emulate_gp(ctxt, 0);
@@ -699,7 +697,10 @@ static int __linearize(struct x86_emulate_ctxt *ctxt,
                                 goto bad;
                 }
                 cpl = ctxt->ops->cpl(ctxt);
-                rpl = sel & 3;
+                if (ctxt->mode == X86EMUL_MODE_REAL)
+                        rpl = 0;
+                else
+                        rpl = sel & 3;
                 cpl = max(cpl, rpl);
                 if (!(desc.type & 8)) {
                         /* data segment */