ARM: KVM: move GIC/timer code to a common location

As KVM/arm64 is looming on the horizon, it makes sense to move some
of the common code to a single location in order to reduce duplication.

The code could live anywhere. Actually, most of KVM is already built
with a bunch of ugly ../../.. hacks in the various Makefiles, so we're
not exactly talking about style here. But maybe it is time to start
moving into a less ugly direction.

The include files must be in a "public" location, as they are accessed
from non-KVM files (arch/arm/kernel/asm-offsets.c).

For this purpose, introduce two new locations:
- virt/kvm/arm/ : x86 and ia64 already share the ioapic code in
  virt/kvm, so this could be seen as a (very ugly) precedent.
- include/kvm/  : there is already an include/xen, and while the
  intent is slightly different, this seems as good a location as
  any

Eventually, we should probably have independant Makefiles at every
levels (just like everywhere else in the kernel), but this is just
the first step.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
(cherry picked from commit 7275acdfe2)
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm/include/asm/kvm_host.h

@@ -23,7 +23,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmio.h>
 #include <asm/fpstate.h>
-#include <asm/kvm_arch_timer.h>
+#include <kvm/arm_arch_timer.h>
 
 #define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS
 #define KVM_USER_MEM_SLOTS 32
@@ -38,7 +38,7 @@
 #define KVM_NR_PAGE_SIZES	1
 #define KVM_PAGES_PER_HPAGE(x)	(1UL<<31)
 
-#include <asm/kvm_vgic.h>
+#include <kvm/arm_vgic.h>
 
 struct kvm_vcpu;
 u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);

arch/arm/kvm/Makefile

@@ -14,10 +14,11 @@ CFLAGS_mmu.o := -I.
 AFLAGS_init.o := -Wa,-march=armv7-a$(plus_virt)
 AFLAGS_interrupts.o := -Wa,-march=armv7-a$(plus_virt)
 
-kvm-arm-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o)
+KVM := ../../../virt/kvm
+kvm-arm-y = $(addprefix $(KVM)/, kvm_main.o coalesced_mmio.o)
 
 obj-y += kvm-arm.o init.o interrupts.o
 obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
 obj-y += coproc.o coproc_a15.o mmio.o psci.o perf.o
-obj-$(CONFIG_KVM_ARM_VGIC) += vgic.o
-obj-$(CONFIG_KVM_ARM_TIMER) += arch_timer.o
+obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o
+obj-$(CONFIG_KVM_ARM_TIMER) += $(KVM)/arm/arch_timer.o

virt/kvm/arm/arch_timer.c

@@ -25,8 +25,8 @@
 #include <clocksource/arm_arch_timer.h>
 #include <asm/arch_timer.h>
 
-#include <asm/kvm_vgic.h>
-#include <asm/kvm_arch_timer.h>
+#include <kvm/arm_vgic.h>
+#include <kvm/arm_arch_timer.h>
 
 static struct timecounter *timecounter;
 static struct workqueue_struct *wqueue;