cpus: Proper range-checking for -icount shift=N

timers_state.icount_time_shift must be in [0,63] to avoid undefined
behavior when shifting by it, e.g. in cpu_icount_to_ns().
icount_adjust() clamps it to [0,MAX_ICOUNT_SHIFT], with
MAX_ICOUNT_SHIFT = 10.  configure_icount() doesn't.  Fix that.

Fixes: a8bfac37085c3372366d722f131a7e18d664ee4d
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200422130719.28225-5-armbru@redhat.com>
1 file changed