Right now when building the qemu command line, we try to do various
unconditional validations of the guest CPU against the host CPU. However
this checks are overly applied. The only time we should use the checks
are:

- The user requests host-model/host-passthrough, or

- When KVM is requsted. CPU features requested in TCG mode are always
  emulated by qemu and are independent of the host CPU, so no host CPU
  checks should be performed.

Right now if trying to specify a CPU for arm on an x86 host, it attempts
to do non-sensical validation and falls over.

Switch all the test cases that were intending to test CPU validation to
use KVM, so they continue to test the intended code.

Amend some aarch64 XML tests with a CPU model, to ensure things work
correctly.

AArch64 qemu has similar behavior as armv7l, like use of mmio etc.
This patch adds similar bypass checks what we have for armv7l to aarch64.
E.g. we are enabling mmio transport for Nicdev.
Making addDefaultUSB and addDefaultMemballoon to false etc.

V3:
- Adding missing domain rng schema for aarcg64 and test case in
  testutilsqemu.c which was causing test suite failure
  while running make check.

V2:
- Added testcase to qemuxml2argvtest as suggested
  during review comments of V1.

V1:
- Initial patch.
Signed-off-by: NAnup Patel <anup.patel@linaro.org>
Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org>

These changes allow the correct virtio-blk-device and virtio-net-device
devices to be used for the 'virt' machine type for armv7 rather than the
PCI virtio devices.

A test case was added to qemuxml2argvtest for this change.
Signed-off-by: NClark Laughlin <clark.laughlin@linaro.org>

Starting with qemu 1.6, the qemu-system-arm vexpress-a9 model has a
hardcoded virtio-mmio transport which enables attaching all virtio
devices.

On the command line, we have to use virtio-XXX-device rather than
virtio-XXX-pci, thankfully s390 already set the precedent here so
it's fairly straight forward.

At the XML level, this adds a new device address type virtio-mmio.
The controller and addressing don't have any subelements at the
moment because we they aren't needed for this usecase, but could
be added later if needed.

Add a test case for an ARM guest with one of every virtio device
enabled.

Similar to the chardev bit, ARM boards depend on the old style '-net nic'
for actually instantiating net devices. But we can't block out
-netdev altogether since it's needed for upcoming virtio support.

And add tests for working ARM XML with console, disk, and networking.

And add test cases for a basic working ARM guest.