[RFC PATCH v6 5/7] psci: Add hvc call service for ptp_kvm.

From: Jianyong Wu
Date: Thu Oct 24 2019 - 07:03:08 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>
---
drivers/clocksource/arm_arch_timer.c | 2 ++
include/clocksource/arm_arch_timer.h | 4 ++++
include/linux/arm-smccc.h | 12 ++++++++++++
virt/kvm/arm/psci.c | 22 ++++++++++++++++++++++
4 files changed, 40 insertions(+)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 07e57a49d1e8..e4ad38042ef6 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -29,6 +29,7 @@
#include <asm/virt.h>

#include <clocksource/arm_arch_timer.h>
+#include <linux/clocksource_ids.h>

#define CNTTIDR 0x08
#define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
@@ -188,6 +189,7 @@ static u64 arch_counter_read_cc(const struct cyclecounter *cc)
static struct clocksource clocksource_counter = {
.name = "arch_sys_counter",
.rating = 400,
+ .id = CSID_ARM_ARCH_COUNTER,
.read = arch_counter_read,
.mask = CLOCKSOURCE_MASK(56),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h
index 1d68d5613dae..426d749e8cf8 100644
--- a/include/clocksource/arm_arch_timer.h
+++ b/include/clocksource/arm_arch_timer.h
@@ -104,6 +104,10 @@ static inline bool arch_timer_evtstrm_available(void)
return false;
}

+bool is_arm_arch_counter(void *unuse)
+{
+ return false;
+}
#endif

#endif
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 6f82c87308ed..aafb6bac167d 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..339bcbafac7b 100644
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -15,6 +15,7 @@
#include <asm/kvm_host.h>

#include <kvm/arm_psci.h>
+#include <linux/clocksource_ids.h>

/*
* This is an implementation of the Power State Coordination Interface
@@ -392,6 +393,8 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
u32 func_id = smccc_get_function(vcpu);
u32 val[4] = {};
u32 option;
+ u64 cycles;
+ struct system_time_snapshot systime_snapshot;

val[0] = SMCCC_RET_NOT_SUPPORTED;

@@ -431,6 +434,25 @@ 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 high 32-bit host ktime;
+ * reg1 stores low 32-bit host ktime;
+ * reg2 stores high 32-bit difference of host cycles and cntvoff;
+ * reg3 stores low 32-bit difference of host cycles and cntvoff.
+ */
+ case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
+ ktime_get_snapshot(&systime_snapshot);
+ if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER)
+ return kvm_psci_call(vcpu);
+ val[0] = systime_snapshot.real >> 32;
+ val[1] = systime_snapshot.real << 32 >> 32;
+ cycles = systime_snapshot.cycles -
+ vcpu_vtimer(vcpu)->cntvoff;
+ val[2] = cycles >> 32;
+ val[3] = cycles << 32 >> 32;
+ break;
default:
return kvm_psci_call(vcpu);
}
--
2.17.1