diff mbox series

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

Message ID 20190802145017.42543-4-steven.price@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Stolen time support | expand

Commit Message

Steven Price Aug. 2, 2019, 2:50 p.m. UTC 
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

Comments

Marc Zyngier Aug. 3, 2019, 11:21 a.m. UTC | #1 
On Fri,  2 Aug 2019 15:50:11 +0100
Steven Price <steven.price@arm.com> wrote:

> 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

Isn't the intent for this to be the same value as
SMCCC_RET_NOT_SUPPORTED?

> +#define PV_VM_TIME_INVALID_PARAMETERS	-2

It overlaps with SMCCC_RET_NOT_REQUIRED. Is that a problem? Should we
consider a spec change for this?

> +
> +#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:


Thanks,

	M.
Steven Price Aug. 5, 2019, 1:14 p.m. UTC | #2 
On 03/08/2019 12:21, Marc Zyngier wrote:
> On Fri,  2 Aug 2019 15:50:11 +0100
> Steven Price <steven.price@arm.com> wrote:
> 
>> 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
> 
> Isn't the intent for this to be the same value as
> SMCCC_RET_NOT_SUPPORTED?

Yes it is, I guess there's not much point defining it again.

>> +#define PV_VM_TIME_INVALID_PARAMETERS	-2
> 
> It overlaps with SMCCC_RET_NOT_REQUIRED. Is that a problem? Should we
> consider a spec change for this?

Actually INVALID_PARAMETERS is only for Live Physical Time, since we're
not implementing it here, this can go as well.

Thanks,

Steve
diff mbox series

Patch

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: