iw

iw is the command-line tool for configuring Linux wireless devices (nl80211).

iw dev

show which interface it is related to phy

Find if it supports AP

$ iw list
Supported interface modes:
	 * IBSS
	 * managed
	 * **AP**
	 * AP/VLAN
	 * WDS
	 * monitor
	 * mesh point

Checking for Virtual Interface capability

iw list | grep "Supported interface modes" -A 8

note: run with sudo if not working

Should output AP/VLAN (not just AP) for full support of VIF (Virtual Interface).

Source