arm64: KVM: Kconfig integration

Finally plug KVM/arm64 into the config system, making it possible
to enable KVM support on AArch64 CPUs.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit c3eb5b1444)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm64/Kconfig

@@ -275,6 +275,8 @@ source "drivers/Kconfig"
 
 source "fs/Kconfig"
 
+source "arch/arm64/kvm/Kconfig"
+
 source "arch/arm64/Kconfig.debug"
 
 source "security/Kconfig"

arch/arm64/kernel/asm-offsets.c

@@ -21,6 +21,7 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
+#include <linux/kvm_host.h>
 #include <asm/thread_info.h>
 #include <asm/memory.h>
 #include <asm/cputable.h>

arch/arm64/kvm/Kconfig

@@ -0,0 +1,51 @@
+#
+# KVM configuration
+#
+
+source "virt/kvm/Kconfig"
+
+menuconfig VIRTUALIZATION
+	bool "Virtualization"
+	---help---
+	  Say Y here to get to see options for using your Linux host to run
+	  other operating systems inside virtual machines (guests).
+	  This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and
+	  disabled.
+
+if VIRTUALIZATION
+
+config KVM
+	bool "Kernel-based Virtual Machine (KVM) support"
+	select MMU_NOTIFIER
+	select PREEMPT_NOTIFIERS
+	select ANON_INODES
+	select KVM_MMIO
+	select KVM_ARM_HOST
+	select KVM_ARM_VGIC
+	select KVM_ARM_TIMER
+	---help---
+	  Support hosting virtualized guest machines.
+
+	  If unsure, say N.
+
+config KVM_ARM_HOST
+	bool
+	---help---
+	  Provides host support for ARM processors.
+
+config KVM_ARM_VGIC
+	bool
+	depends on KVM_ARM_HOST && OF
+	select HAVE_KVM_IRQCHIP
+	---help---
+	  Adds support for a hardware assisted, in-kernel GIC emulation.
+
+config KVM_ARM_TIMER
+	bool
+	depends on KVM_ARM_VGIC
+	---help---
+	  Adds support for the Architected Timers in virtual machines.
+
+endif # VIRTUALIZATION