Have compile this and tested on an AWS M4 instance. Interface comes up now with DHCP successfully and I can connect.
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root@ip-172-31-8-215:/usr/src # uname -a
FreeBSD ip-172-31-8-215 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r293137M: Mon Jan 4 11:24:40 UTC 2016 root@ip-172-31-8-215:/usr/obj/usr/src/sys/GENERIC amd64
root@ip-172-31-8-215:/usr/src # dmesg
Copyright (c) 1992-2016 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 11.0-CURRENT #0 r293137M: Mon Jan 4 11:24:40 UTC 2016
root@ip-172-31-8-215:/usr/obj/usr/src/sys/GENERIC amd64
FreeBSD clang version 3.7.1 (tags/RELEASE_371/final 255217) 20151225
WARNING: WITNESS option enabled, expect reduced performance.
VT(vga): resolution 640x480
XEN: Hypervisor version 4.2 detected.
CPU: Intel(R) Xeon(R) CPU E5-2676 v3 @ 2.40GHz (2400.05-MHz K8-class CPU)
Origin="GenuineIntel" Id=0x306f2 Family=0x6 Model=0x3f Stepping=2
Features=0x1783fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE,SSE2,HTT>
Features2=0xfffa3203<SSE3,PCLMULQDQ,SSSE3,FMA,CX16,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,TSCDLT,AESNI,XSAVE,OSXSAVE,AVX,F16C,RDRAND,HV>
AMD Features=0x28100800<SYSCALL,NX,RDTSCP,LM>
AMD Features2=0x21<LAHF,ABM>
Structured Extended Features=0x728<BMI1,AVX2,BMI2,ERMS,INVPCID>
XSAVE Features=0x1<XSAVEOPT>
Hypervisor: Origin = "XenVMMXenVMM"
real memory = 8589934592 (8192 MB)
avail memory = 8270520320 (7887 MB)
Event timer "LAPIC" quality 400
ACPI APIC Table: <Xen HVM>
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
FreeBSD/SMP: 1 package(s) x 1 core(s) x 2 SMT threads
cpu0 (BSP): APIC ID: 0
cpu1 (AP): APIC ID: 1
ioapic0: Changing APIC ID to 1
MADT: Forcing active-low polarity and level trigger for SCI
ioapic0 <Version 1.1> irqs 0-47 on motherboard
random: entropy device external interface
kbd1 at kbdmux0
netmap: loaded module
module_register_init: MOD_LOAD (vesa, 0xffffffff80edeed0, 0) error 19
random: registering fast source Intel Secure Key RNG
random: fast provider: "Intel Secure Key RNG"
vtvga0: <VT VGA driver> on motherboard
cryptosoft0: <software crypto> on motherboard
acpi0: <Xen> on motherboard
acpi0: Power Button (fixed)
acpi0: Sleep Button (fixed)
cpu0: <ACPI CPU> on acpi0
cpu1: <ACPI CPU> on acpi0
hpet0: <High Precision Event Timer> iomem 0xfed00000-0xfed003ff on acpi0
Timecounter "HPET" frequency 62500000 Hz quality 950
attimer0: <AT timer> port 0x40-0x43 irq 0 on acpi0
Timecounter "i8254" frequency 1193182 Hz quality 0
Event timer "i8254" frequency 1193182 Hz quality 100
atrtc0: <AT realtime clock> port 0x70-0x71 irq 8 on acpi0
Event timer "RTC" frequency 32768 Hz quality 0
Timecounter "ACPI-fast" frequency 3579545 Hz quality 900
acpi_timer0: <32-bit timer at 3.579545MHz> port 0xb008-0xb00b on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
isab0: <PCI-ISA bridge> at device 1.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel PIIX3 WDMA2 controller> port 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xc100-0xc10f at device 1.1 on pci0
ata0: <ATA channel> at channel 0 on atapci0
ata1: <ATA channel> at channel 1 on atapci0
pci0: <bridge> at device 1.3 (no driver attached)
vgapci0: <VGA-compatible display> mem 0xf0000000-0xf1ffffff,0xf3008000-0xf3008fff at device 2.0 on pci0
vgapci0: Boot video device
ixv0: <Intel(R) PRO/10GbE Virtual Function Network Driver, Version - 1.4.6-k> mem 0xf3000000-0xf3003fff,0xf3004000-0xf3007fff at device 3.0 on pci0
ixv0: Using MSIX interrupts with 2 vectors
ixv0: Ethernet address: 02:e2:5e:25:5e:dd
ixv0: netmap queues/slots: TX 1/1024, RX 1/1024
xenpci0: <Xen Platform Device> port 0xc000-0xc0ff mem 0xf2000000-0xf2ffffff irq 47 at device 31.0 on pci0
atkbdc0: <Keyboard controller (i8042)> port 0x60,0x64 irq 1 on acpi0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
psm0: <PS/2 Mouse> irq 12 on atkbdc0
psm0: [GIANT-LOCKED]
psm0: model IntelliMouse Explorer, device ID 4
fdc0: <floppy drive controller> port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on acpi0
fdc0: does not respond
device_attach: fdc0 attach returned 6
uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
uart0: console (9600,n,8,1)
xenpv0: <Xen PV bus> on motherboard
granttable0: <Xen Grant-table Device> on xenpv0
xen_et0: <Xen PV Clock> on xenpv0
Event timer "XENTIMER" frequency 1000000000 Hz quality 950
Timecounter "XENTIMER" frequency 1000000000 Hz quality 950
xenstore0: <XenStore> on xenpv0
evtchn0: <Xen event channel user-space device> on xenpv0
privcmd0: <Xen privileged interface user-space device> on xenpv0
debug0: <Xen debug handler> on xenpv0
fdc0: No FDOUT register!
ppc0: cannot reserve I/O port range
Timecounters tick every 1.000 msec
IPsec: Initialized Security Association Processing.
xenballoon0: <Xen Balloon Device> on xenstore0
xctrl0: <Xen Control Device> on xenstore0
xs_dev0: <Xenstore user-space device> on xenstore0
xenbusb_front0: <Xen Frontend Devices> on xenstore0
xenbusb_back0: <Xen Backend Devices> on xenstore0
xbd0: 20480MB <Virtual Block Device> at device/vbd/768 on xenbusb_front0
xbd0: attaching as ada0
SMP: AP CPU #1 Launched!
WARNING: WITNESS option enabled, expect reduced performance.
Trying to mount root from ufs:/dev/gpt/rootfs [rw]...
random: unblocking device.
ixv0: link state changed to UP
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