KVM: PPC: Generic KVM PV guest support

We have all the hypervisor pieces in place now, but the guest parts are still
missing.

This patch implements basic awareness of KVM when running Linux as guest. It
doesn't do anything with it yet though.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/kernel/kvm.c

@@ -30,6 +30,9 @@
 #include <asm/cacheflush.h>
 #include <asm/disassemble.h>
 
+#define KVM_MAGIC_PAGE		(-4096L)
+#define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
+
 unsigned long kvm_hypercall(unsigned long *in,
 			    unsigned long *out,
 			    unsigned long nr)