KVM: improve arch vcpu request defining

Marc Zyngier suggested that we define the arch specific VCPU request
base, rather than requiring each arch to remember to start from 8.
That suggestion, along with Radim Krcmar's recent VCPU request flag
addition, snowballed into defining something of an arch VCPU request
defining API.

No functional change.

(Looks like x86 is running out of arch VCPU request bits.  Maybe
 someday we'll need to extend to 64.)

Signed-off-by: Andrew Jones <drjones@redhat.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 9c51ac4..50e0bc9 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -52,8 +52,8 @@
 #define KVM_IRQCHIP_NUM_PINS     256
 
 /* PPC-specific vcpu->requests bit members */
-#define KVM_REQ_WATCHDOG           8
-#define KVM_REQ_EPR_EXIT           9
+#define KVM_REQ_WATCHDOG	KVM_ARCH_REQ(0)
+#define KVM_REQ_EPR_EXIT	KVM_ARCH_REQ(1)
 
 #include <linux/mmu_notifier.h>