ARM/KVM: save and restore generic timer registers

For migration to work we need to save (and later restore) the state of
each core's virtual generic timer.
Since this is per VCPU, we can use the [gs]et_one_reg ioctl and export
the three needed registers (control, counter, compare value).
Though they live in cp15 space, we don't use the existing list, since
they need special accessor functions and the arch timer is optional.

Acked-by: Marc Zynger <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index c498b60c0505..835b8678de03 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -119,6 +119,26 @@ struct kvm_arch_memory_slot {
 #define KVM_REG_ARM_32_CRN_MASK		0x0000000000007800
 #define KVM_REG_ARM_32_CRN_SHIFT	11
 
+#define ARM_CP15_REG_SHIFT_MASK(x,n) \
+	(((x) << KVM_REG_ARM_ ## n ## _SHIFT) & KVM_REG_ARM_ ## n ## _MASK)
+
+#define __ARM_CP15_REG(op1,crn,crm,op2) \
+	(KVM_REG_ARM | (15 << KVM_REG_ARM_COPROC_SHIFT) | \
+	ARM_CP15_REG_SHIFT_MASK(op1, OPC1) | \
+	ARM_CP15_REG_SHIFT_MASK(crn, 32_CRN) | \
+	ARM_CP15_REG_SHIFT_MASK(crm, CRM) | \
+	ARM_CP15_REG_SHIFT_MASK(op2, 32_OPC2))
+
+#define ARM_CP15_REG32(...) (__ARM_CP15_REG(__VA_ARGS__) | KVM_REG_SIZE_U32)
+
+#define __ARM_CP15_REG64(op1,crm) \
+	(__ARM_CP15_REG(op1, 0, crm, 0) | KVM_REG_SIZE_U64)
+#define ARM_CP15_REG64(...) __ARM_CP15_REG64(__VA_ARGS__)
+
+#define KVM_REG_ARM_TIMER_CTL		ARM_CP15_REG32(0, 14, 3, 1)
+#define KVM_REG_ARM_TIMER_CNT		ARM_CP15_REG64(1, 14) 
+#define KVM_REG_ARM_TIMER_CVAL		ARM_CP15_REG64(3, 14) 
+
 /* Normal registers are mapped as coprocessor 16. */
 #define KVM_REG_ARM_CORE		(0x0010 << KVM_REG_ARM_COPROC_SHIFT)
 #define KVM_REG_ARM_CORE_REG(name)	(offsetof(struct kvm_regs, name) / 4)