[RFC PATCH v3 4/6] psci: Add hvc call service for ptp_kvm.

[Jianyong Wu <jianyong.wu@arm.com>]

This patch is the base of ptp_kvm for arm64.
ptp_kvm modules will call hvc to get this service.
The service offers real time and counter cycle of host for guest.

Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
---
 include/linux/arm-smccc.h | 12 ++++++++++++
 virt/kvm/arm/psci.c       | 17 +++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index a6e4d3e3d10a..bc0cdad10f35 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -94,6 +94,7 @@
 
 /* KVM "vendor specific" services */
 #define ARM_SMCCC_KVM_FUNC_FEATURES		0
+#define ARM_SMCCC_KVM_PTP			1
 #define ARM_SMCCC_KVM_FUNC_FEATURES_2		127
 #define ARM_SMCCC_KVM_NUM_FUNCS			128
 
@@ -103,6 +104,17 @@
 			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
 			   ARM_SMCCC_KVM_FUNC_FEATURES)
 
+/*
+ * This ID used for virtual ptp kvm clock and it will pass second value
+ * and nanosecond value of host real time and system counter by vcpu
+ * register to guest.
+ */
+#define ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
+			   ARM_SMCCC_SMC_32,				\
+			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
+			   ARM_SMCCC_KVM_PTP)
+
 #ifndef __ASSEMBLY__
 
 #include <linux/linkage.h>
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index 0debf49bf259..2c5d53817a28 100644
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -392,6 +392,8 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 	u32 func_id = smccc_get_function(vcpu);
 	u32 val[4] = {};
 	u32 option;
+	struct timespec *ts;
+	struct system_counterval_t sc;
 
 	val[0] = SMCCC_RET_NOT_SUPPORTED;
 
@@ -431,6 +433,21 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
 		val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES);
 		break;
+	/*
+	 * This will used for virtual ptp kvm clock. three
+	 * values will be passed back.
+	 * reg0 stores seconds of host real time;
+	 * reg1 stores nanoseconds of host real time;
+	 * reg2 stores system counter cycle value.
+	 */
+	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
+		getnstimeofday(ts);
+		get_current_counterval(&sc);
+		val[0] = ts->tv_sec;
+		val[1] = ts->tv_nsec;
+		val[2] = sc.cycles;
+		val[3] = 0;
+		break;
 	default:
 		return kvm_psci_call(vcpu);
 	}
-- 
2.17.1