KVM: Document KVM specific review items

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Documentation/kvm/review-checklist.txt

+Review checklist for kvm patches
+================================
+
+1.  The patch must follow Documentation/CodingStyle and
+    Documentation/SubmittingPatches.
+
+2.  Patches should be against kvm.git master branch.
+
+3.  If the patch introduces or modifies a new userspace API:
+    - the API must be documented in Documentation/kvm/api.txt
+    - the API must be discoverable using KVM_CHECK_EXTENSION
+
+4.  New state must include support for save/restore.
+
+5.  New features must default to off (userspace should explicitly request them).
+    Performance improvements can and should default to on.
+
+6.  New cpu features should be exposed via KVM_GET_SUPPORTED_CPUID2
+
+7.  Emulator changes should be accompanied by unit tests for qemu-kvm.git
+    kvm/test directory.
+
+8.  Changes should be vendor neutral when possible.  Changes to common code
+    are better than duplicating changes to vendor code.
+
+9.  Similarly, prefer changes to arch independent code than to arch dependent
+    code.
+
+10. User/kernel interfaces and guest/host interfaces must be 64-bit clean
+    (all variables and sizes naturally aligned on 64-bit; use specific types
+    only - u64 rather than ulong).
+
+11. New guest visible features must either be documented in a hardware manual
+    or be accompanied by documentation.
+
+12. Features must be robust against reset and kexec - for example, shared
+    host/guest memory must be unshared to prevent the host from writing to
+    guest memory that the guest has not reserved for this purpose.