On 8/24/2017 11:50 PM, Paolo Bonzini wrote:
On 24/08/2017 17:23, Yu Zhang wrote:
static inline u64 rsvd_bits(int s, int e)
{
+ if (e < s)
+ return 0;
+
return ((1ULL << (e - s + 1)) - 1) << s;
}
e = s - 1 is already supported; why do you need e <= s - 2?
Sorry? I do not quite understand. When will e = s - 1?
Is there any case where e < s? I can see that MAXPHYADDR=63 gives
rsvd_bits(63, 62), but that works.
In practice, MAXPHYADDR will never be 59 even because the PKRU bits are
at bits 59..62.
Thanks, Paolo.
I see. I had made an assumption that MAXPHYADDR shall not exceed the
physical one,
which is 52 I believe. But I'm not sure there's any place to check this.
Maybe we should make sure the vcpu->arch.maxphyaddr will not be greater
than the
value of the host?
Yu
Paolo
