bhyve: improve memory size documentation

A couple of minor memory size option related nits:

 - use common name 'memsize' (instead of 'max-size' or just 'size')
 - bhyve: update usage with memsize unit suffix, drop legacy "MB"
   unit
 - bhyveload: update usage with memsize unit suffix
 - bhyve(8): document default size
 - bhyveload(8): use memsize formatting like it's done
   in bhyve(8)

Reviewed by:            wblock, grehan
Approved by:            re (kib), wblock, grehan
Differential Revision:  https://reviews.freebsd.org/D6952

usr.sbin/bhyve/bhyve.8

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 18, 2016
+.Dd June 24, 2016
 .Dt BHYVE 8
 .Os
 .Sh NAME
@@ -36,7 +36,7 @@
 .Op Fl c Ar numcpus
 .Op Fl g Ar gdbport
 .Op Fl l Ar lpcdev Ns Op , Ns Ar conf
-.Op Fl m Ar size Ns Op Ar K|k|M|m|G|g|T|t
+.Op Fl m Ar memsize Ns Op Ar K|k|M|m|G|g|T|t
 .Op Fl p Ar vcpu:hostcpu
 .Op Fl s Ar slot,emulation Ns Op , Ns Ar conf
 .Op Fl U Ar uuid
@@ -105,7 +105,7 @@ and
 .Ar com2
 and the boot ROM device
 .Ar bootrom .
-.It Fl m Ar size Ns Op Ar K|k|M|m|G|g|T|t
+.It Fl m Ar memsize Ns Op Ar K|k|M|m|G|g|T|t
 Guest physical memory size in bytes.
 This must be the same size that was given to
 .Xr bhyveload 8 .
@@ -114,6 +114,9 @@ The size argument may be suffixed with one of K, M, G or T (either upper
 or lower case) to indicate a multiple of kilobytes, megabytes, gigabytes,
 or terabytes.
 If no suffix is given, the value is assumed to be in megabytes.
+.Pp
+.Ar memsize
+defaults to 256M.
 .It Fl p Ar vcpu:hostcpu
 Pin guest's virtual CPU
 .Em vcpu

usr.sbin/bhyve/bhyverun.c

@@ -125,7 +125,7 @@ usage(int code)
 
         fprintf(stderr,
                 "Usage: %s [-abehuwxACHPSWY] [-c vcpus] [-g <gdb port>] [-l <lpc>]\n"
-		"       %*s [-m mem] [-p vcpu:hostcpu] [-s <pci>] [-U uuid] <vm>\n"
+		"       %*s [-m memsize[K|k|M|m|G|g|T|t]] [-p vcpu:hostcpu] [-s <pci>] [-U uuid] <vm>\n"
 		"       -a: local apic is in xAPIC mode (deprecated)\n"
 		"       -A: create ACPI tables\n"
 		"       -c: # cpus (default 1)\n"
@@ -135,7 +135,7 @@ usage(int code)
 		"       -h: help\n"
 		"       -H: vmexit from the guest on hlt\n"
 		"       -l: LPC device configuration\n"
-		"       -m: memory size in MB\n"
+		"       -m: memory size\n"
 		"       -p: pin 'vcpu' to 'hostcpu'\n"
 		"       -P: vmexit from the guest on pause\n"
 		"       -s: <slot,driver,configinfo> PCI slot config\n"

usr.sbin/bhyveload/bhyveload.8

@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 26, 2016
+.Dd June 24, 2016
 .Dt BHYVELOAD 8
 .Os
 .Sh NAME
@@ -42,7 +42,7 @@ guest inside a bhyve virtual machine
 .Op Fl e Ar name=value
 .Op Fl h Ar host-path
 .Op Fl l Ar os-loader
-.Op Fl m Ar mem-size
+.Op Fl m Ar memsize Ns Op Ar K|k|M|m|G|g|T|t
 .Ar vmname
 .Sh DESCRIPTION
 .Nm
@@ -103,16 +103,12 @@ will use
 which presents a standard
 .Fx
 loader.
-.It Fl m Ar mem-size Xo
-.Sm off
-.Op Cm K | k | M | m | G | g | T | t
-.Xc
-.Sm on
-.Ar mem-size
+.It Fl m Ar memsize Ns Op Ar K|k|M|m|G|g|T|t
+.Ar memsize
 is the amount of memory allocated to the guest.
 .Pp
 The
-.Ar mem-size
+.Ar memsize
 argument may be suffixed with one of
 .Cm K ,
 .Cm M ,
@@ -123,9 +119,8 @@ or
 Kilobytes, Megabytes, Gigabytes or Terabytes
 respectively.
 .Pp
-The default value of
-.Ar mem-size
-is 256M.
+.Ar memsize
+defaults to 256M.
 .It Fl C
 Include guest memory in the core file when
 .Nm

usr.sbin/bhyveload/bhyveload.c

@@ -648,7 +648,7 @@ usage(void)
 
 	fprintf(stderr,
 	    "usage: %s [-S][-c <console-device>] [-d <disk-path>] [-e <name=value>]\n"
-	    "       %*s [-h <host-path>] [-m mem-size] <vmname>\n",
+	    "       %*s [-h <host-path>] [-m memsize[K|k|M|m|G|g|T|t]] <vmname>\n",
 	    progname,
 	    (int)strlen(progname), "");
 	exit(1);