Index: usr.sbin/bhyve/Makefile
===================================================================
--- usr.sbin/bhyve/Makefile
+++ usr.sbin/bhyve/Makefile
@@ -70,7 +70,7 @@
 .PATH:  ${BHYVE_SYSDIR}/sys/amd64/vmm
 SRCS+=	vmm_instruction_emul.c
 
-LIBADD=	vmmapi md pthread z util sbuf cam
+LIBADD=	vmmapi md pthread z util sbuf cam xo
 
 .if ${MK_OPENSSL} == "no"
 CFLAGS+=-DNO_OPENSSL
Index: usr.sbin/bhyve/bhyverun.c
===================================================================
--- usr.sbin/bhyve/bhyverun.c
+++ usr.sbin/bhyve/bhyverun.c
@@ -58,6 +58,7 @@
 #include <sysexits.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include <libxo/xo.h>
 
 #include <machine/vmm.h>
 #ifndef WITHOUT_CAPSICUM
@@ -141,7 +142,7 @@
 {
 
         fprintf(stderr,
-		"Usage: %s [-abehuwxACHPSWY]\n"
+		"Usage: %s [-abefhuwxACHPSWY]\n"
 		"       %*s [-c [[cpus=]numcpus][,sockets=n][,cores=n][,threads=n]]\n"
 		"       %*s [-g <gdb port>] [-l <lpc>]\n"
 		"       %*s [-m mem] [-p vcpu:hostcpu] [-s <pci>] [-U uuid] <vm>\n"
@@ -150,6 +151,7 @@
 		"       -c: number of cpus and/or topology specification\n"
 		"       -C: include guest memory in core file\n"
 		"       -e: exit on unhandled I/O access\n"
+		"	-f: show supported emulator features\n"
 		"       -g: gdb port\n"
 		"       -h: help\n"
 		"       -H: vmexit from the guest on hlt\n"
@@ -171,6 +173,85 @@
 	exit(code);
 }
 
+static void
+show_emulator_features()
+{
+	/* top-level container */
+	xo_open_container("bhyve");
+	xo_emit("{L:Schema version}: {:schema_version}\n", "1.0");
+	/* features collection container */
+	xo_open_container("features");
+
+	/* rtc_utc */
+	xo_open_container("feature");
+        xo_open_container("rtc_utc");
+	xo_emit("\n{T:rtc_utc}\n");
+	xo_emit("{L:Description}: {:description}\n", "RTC keeps UTC time");
+
+	xo_open_container("cmd");
+	xo_emit("{L:Command line switch}: {:switch}\n", "-u");
+	xo_close_container("cmd");
+
+	xo_close_container("rtc_utc");
+	xo_close_container("feature");
+
+	/* wire_guest_memory */
+	xo_open_container("feature");
+        xo_open_container("wire_guest_memory");
+	xo_emit("\n{T:wire_guest_memory}\n");
+	xo_emit("{L:Description}: {:description}\n", "Wire guest memory");
+
+	xo_open_container("cmd");
+	xo_emit("{L:Command line switch}: {:switch}\n", "-S");
+	xo_close_container("cmd");
+
+	xo_close_container("wire_guest_memory");
+	xo_close_container("feature");
+
+	/* devices */
+	xo_open_container("feature");
+        xo_open_container("devices");
+	xo_emit("\n{T:devices}\n");
+	xo_emit("{L:Description}: {:description}\n", "Devices support");
+
+	xo_open_container("cmd");
+	xo_emit("{L:Command line switch}: {:switch}\n", "-s");
+
+	xo_open_list("arguments");
+
+	/* virtio-net */
+	xo_open_instance("arguments");
+	xo_emit("{L:Arguments}: {:options/%s} {L:Description}: {:description/%s}\n",
+		"virtio-net,tapN,mac=xx:xx:xx:xx:xx:xx",
+		"Virtio network device");
+	xo_close_instance("arguments");
+
+        /* virtio-block */
+	xo_open_instance("arguments");
+	xo_emit("{L:Arguments}: {:options/%s} {L:Description}: {:description/%s}\n",
+		"virtio-blk,path,nocache,direct,ro,sectorsize=logical/physical",
+		"Virtio block device");
+	xo_close_instance("arguments");
+
+        /* fbuf */
+	xo_open_instance("arguments");
+	xo_emit("{L:Arguments}: '{:options/%s}' {L:Description}: {:description/%s}\n",
+		"fbuf,rfb,rfb=IP:port,w=width,h=heigh,vga=vgaconf,wait,password=password",
+		"Framebuffer device");
+	xo_close_instance("arguments");
+
+	xo_close_list("arguments");
+
+	xo_close_container("cmd");
+
+	xo_close_container("devices");
+	xo_close_container("feature");
+
+	xo_close_container("features");
+	xo_close_container("bhyve");
+	xo_finish();
+}
+
 /*
  * XXX This parser is known to have the following issues:
  * 1.  It accepts null key=value tokens ",,".
@@ -922,7 +1003,11 @@
 	rtc_localtime = 1;
 	memflags = 0;
 
-	optstr = "abehuwxACHIPSWYp:g:G:c:s:m:l:U:";
+	argc = xo_parse_args(argc, argv);
+	if (argc < 0)
+		exit(1);
+
+	optstr = "abefhuwxACHIPSWYp:g:G:c:s:m:l:U:";
 	while ((c = getopt(argc, argv, optstr)) != -1) {
 		switch (c) {
 		case 'a':
@@ -949,6 +1034,10 @@
 		case 'C':
 			memflags |= VM_MEM_F_INCORE;
 			break;
+		case 'f':
+			show_emulator_features();
+			exit(0);
+			break;
 		case 'g':
 			dbg_port = atoi(optarg);
 			break;