KVM: x86: 32-bit wraparound read/write not emulated correctly
If we got a wraparound of 32-bit operand, and the limit is 0xffffffff, read and
writes should be successful. It just needs to be done in two segments.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 997c9eb..c3b0757 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -684,9 +684,13 @@
}
if (addr.ea > lim)
goto bad;
- *max_size = min_t(u64, ~0u, (u64)lim + 1 - addr.ea);
- if (size > *max_size)
- goto bad;
+ if (lim == 0xffffffff)
+ *max_size = ~0u;
+ else {
+ *max_size = (u64)lim + 1 - addr.ea;
+ if (size > *max_size)
+ goto bad;
+ }
la &= (u32)-1;
break;
}