[PATCH 3/9] KVM: arm64: Implement PV_FEATURES call

Steven Price
2019-08-02T14:51:27Z

This provides a mechanism for querying which paravirtualized features
are available in this hypervisor.

Also add the header file which defines the ABI for the paravirtualized
clock features we're about to add.

Signed-off-by: Steven Price <steven.price@arm.com>
---
arch/arm64/include/asm/pvclock-abi.h | 20 ++++++++++++++++++++
include/linux/arm-smccc.h | 14 ++++++++++++++
virt/kvm/arm/hypercalls.c | 9 +++++++++
3 files changed, 43 insertions(+)
create mode 100644 arch/arm64/include/asm/pvclock-abi.h

diff --git a/arch/arm64/include/asm/pvclock-abi.h b/arch/arm64/include/asm/pvclock-abi.h
new file mode 100644
index 000000000000..1f7cdc102691
--- /dev/null
+++ b/arch/arm64/include/asm/pvclock-abi.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 Arm Ltd. */
+
+#ifndef __ASM_PVCLOCK_ABI_H
+#define __ASM_PVCLOCK_ABI_H
+
+/* The below structures and constants are defined in ARM DEN0057A */
+
+struct pvclock_vcpu_stolen_time_info {
+ __le32 revision;
+ __le32 attributes;
+ __le64 stolen_time;
+ /* Structure must be 64 byte aligned, pad to that size */
+ u8 padding[48];
+} __packed;
+
+#define PV_VM_TIME_NOT_SUPPORTED -1
+#define PV_VM_TIME_INVALID_PARAMETERS -2
+
+#endif
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 080012a6f025..e7f129f26ebd 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -45,6 +45,7 @@
#define ARM_SMCCC_OWNER_SIP 2
#define ARM_SMCCC_OWNER_OEM 3
#define ARM_SMCCC_OWNER_STANDARD 4
+#define ARM_SMCCC_OWNER_STANDARD_HYP 5
#define ARM_SMCCC_OWNER_TRUSTED_APP 48
#define ARM_SMCCC_OWNER_TRUSTED_APP_END 49
#define ARM_SMCCC_OWNER_TRUSTED_OS 50
@@ -302,5 +303,18 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
#define SMCCC_RET_NOT_SUPPORTED -1
#define SMCCC_RET_NOT_REQUIRED -2

+/* Paravirtualised time calls (defined by ARM DEN0057A) */
+#define ARM_SMCCC_HV_PV_FEATURES \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_64, \
+ ARM_SMCCC_OWNER_STANDARD_HYP, \
+ 0x20)
+
+#define ARM_SMCCC_HV_PV_TIME_ST \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_64, \
+ ARM_SMCCC_OWNER_STANDARD_HYP, \
+ 0x22)
+
#endif /*__ASSEMBLY__*/
#endif /*__LINUX_ARM_SMCCC_H*/
diff --git a/virt/kvm/arm/hypercalls.c b/virt/kvm/arm/hypercalls.c
index f875241bd030..2906b2df99df 100644
--- a/virt/kvm/arm/hypercalls.c
+++ b/virt/kvm/arm/hypercalls.c
@@ -5,6 +5,7 @@
#include <linux/kvm_host.h>

#include <asm/kvm_emulate.h>
+#include <asm/pvclock-abi.h>

#include <kvm/arm_hypercalls.h>
#include <kvm/arm_psci.h>
@@ -48,6 +49,14 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
break;
}
break;
+ case ARM_SMCCC_HV_PV_FEATURES:
+ val = SMCCC_RET_SUCCESS;
+ break;
+ }
+ break;
+ case ARM_SMCCC_HV_PV_FEATURES:
+ feature = smccc_get_arg1(vcpu);
+ switch (feature) {
}
break;
default:
--
2.20.1