Need patched QEMU 2.7.0 for DPDK

The following changes need to be made to the "nova-compute" charm to install a patched version of QEMU 2.7.0 on the compute nodes.

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index a07dc81..8ebbcb4 100644
— a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -441,7 +441,7 @@ static void pc_i440fx_machine_options(MachineClass *m)
static void pc_i440fx_2_7_machine_options(MachineClass *m)

{ pc_i440fx_machine_options(m); - m->alias = "pc"; + m->alias = "ubuntu"; m->is_default = 1; }

sudo apt-get install -y glib-2.0 libglib2.0-dev libnuma-dev

git clone git://git.qemu.org/qemu.git && cd qemu
git checkout v2.7.0

1. apply the above patch
   mkdir bin && cd bin

../configure --target-list=x86_64-softmmu --enable-debug --extra-cflags='-g'
sudo make -j install
sudo cp /usr/local/bin/qemu-system-x86_64 /usr/bin/qemu-system-x86_64