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

From: Jianyong Wu
Date: Wed Sep 18 2019 - 04:08:00 EST


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@xxxxxxx>
---
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