docs: Move AArch64 hardware requirements to README

Also drop the SWAP enabling requirements for AArch64 because this
is an AArch64 specific issue.

Signed-off-by: Henry Wang <Henry.Wang@arm.com>

README.md

@@ -69,10 +69,12 @@ Cloud Hypervisor supports `64-bit Linux` and Windows 10/Windows Server 2019.
 
 # 2. Getting Started
 
-The following sections describe how to build and run Cloud Hypervisor on the
-`x86-64` platform. For getting started on the `AArch64` platform, please refer
-to the
-[AArch64 documentation](docs/arm64.md).
+The following sections describe how to build and run Cloud Hypervisor.
+
+## Prerequisites for AArch64
+
+- AArch64 servers (recommended) or development boards equipped with the GICv3
+  interrupt controller.
 
 ## Host OS
 

docs/arm64.md

@@ -7,22 +7,6 @@ booting and direct-kernel booting. The document covers both methods.
 All the steps are based on Ubuntu. We use the Ubuntu cloud image for guest VM
 disk.
 
-## Hardware requirements
-
-- AArch64 servers (recommended) or development boards equipped with the GICv3
-interrupt controller.
-
-- On development boards that have constrained RAM resources, if the creation of
-a VM consumes a large portion of the free memory on the host, it may be required
-to enable swap. For example, this was required on a board with 3 GB of RAM
-booting a 2 GB VM at a point in time when 2.8 GB were free. Without enabling
-swap the `cloud-hypervisor` process was terminated by the OOM killer. In this
-situation memory was allocated for the virtual machine using memfd while the
-page cache was filled, leading to a situation where the kernel could not even
-drop caches. Making a small section of swap available (observably, 1 to 15 MB),
-this situation can be resolved and the resulting memory footprint of
-`cloud-hypervisor` is as expected.
-
 ## Getting started
 
 We create a folder to build and run Cloud Hypervisor at `$HOME/cloud-hypervisor`