This service allows guests to query the host for frequency of the CPU that the vCPU is currently running on. Co-developed-by: Saravana Kannan <saravanak@xxxxxxxxxx> Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> Signed-off-by: David Dai <davidai@xxxxxxxxxx> --- Documentation/virt/kvm/api.rst | 8 +++++++ .../virt/kvm/arm/get_cur_cpufreq.rst | 21 +++++++++++++++++++ Documentation/virt/kvm/arm/index.rst | 1 + arch/arm64/include/uapi/asm/kvm.h | 1 + arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/hypercalls.c | 18 ++++++++++++++++ include/linux/arm-smccc.h | 7 +++++++ include/uapi/linux/kvm.h | 1 + tools/arch/arm64/include/uapi/asm/kvm.h | 1 + 9 files changed, 59 insertions(+) create mode 100644 Documentation/virt/kvm/arm/get_cur_cpufreq.rst diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 62de0768d6aa..b0ff0ad700bf 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8380,6 +8380,14 @@ structure. When getting the Modified Change Topology Report value, the attr->addr must point to a byte where the value will be stored or retrieved from. +8.40 KVM_CAP_GET_CUR_CPUFREQ +------------------------ + +:Architectures: arm64 + +This capability indicates that KVM supports getting the +frequency of the current CPU that the vCPU thread is running on. + 9. Known KVM API problems ========================= diff --git a/Documentation/virt/kvm/arm/get_cur_cpufreq.rst b/Documentation/virt/kvm/arm/get_cur_cpufreq.rst new file mode 100644 index 000000000000..06e0ed5b3868 --- /dev/null +++ b/Documentation/virt/kvm/arm/get_cur_cpufreq.rst @@ -0,0 +1,21 @@ +.. SPDX-License-Identifier: GPL-2.0 + +get_cur_cpufreq support for arm/arm64 +============================= + +Get_cur_cpufreq support is used to get current frequency(in KHz) of the +current CPU that the vCPU thread is running on. + +* ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID: 0x86000040 + +This hypercall uses the SMC32/HVC32 calling convention: + +ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID + ============== ======== ===================================== + Function ID: (uint32) 0x86000040 + Return Values: (int32) NOT_SUPPORTED(-1) on error, or + (uint32) Frequency in KHz of current CPU that the + vCPU thread is running on. + Endianness: Must be the same endianness + as the host. + ============== ======== ===================================== diff --git a/Documentation/virt/kvm/arm/index.rst b/Documentation/virt/kvm/arm/index.rst index e84848432158..47afc5c1f24a 100644 --- a/Documentation/virt/kvm/arm/index.rst +++ b/Documentation/virt/kvm/arm/index.rst @@ -11,3 +11,4 @@ ARM hypercalls pvtime ptp_kvm + get_cur_cpufreq diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index f8129c624b07..ed8b63e91bdc 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -367,6 +367,7 @@ enum { enum { KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT = 0, KVM_REG_ARM_VENDOR_HYP_BIT_PTP = 1, + KVM_REG_ARM_VENDOR_HYP_BIT_GET_CUR_CPUFREQ = 2, #ifdef __KERNEL__ KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT, #endif diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3bd732eaf087..f960b136c611 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -220,6 +220,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_VCPU_ATTRIBUTES: case KVM_CAP_PTP_KVM: case KVM_CAP_ARM_SYSTEM_SUSPEND: + case KVM_CAP_GET_CUR_CPUFREQ: r = 1; break; case KVM_CAP_SET_GUEST_DEBUG2: diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 5da884e11337..b3f4b90c024b 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -3,6 +3,9 @@ #include <linux/arm-smccc.h> #include <linux/kvm_host.h> +#include <linux/cpufreq.h> +#include <linux/sched.h> +#include <uapi/linux/sched/types.h> #include <asm/kvm_emulate.h> @@ -16,6 +19,15 @@ #define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES \ GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT - 1, 0) +static void kvm_sched_get_cur_cpufreq(struct kvm_vcpu *vcpu, u64 *val) +{ + unsigned long ret_freq; + + ret_freq = cpufreq_get(task_cpu(current)); + + val[0] = ret_freq; +} + static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val) { struct system_time_snapshot systime_snapshot; @@ -116,6 +128,9 @@ static bool kvm_hvc_call_allowed(struct kvm_vcpu *vcpu, u32 func_id) case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID: return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_PTP, &smccc_feat->vendor_hyp_bmap); + case ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID: + return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_GET_CUR_CPUFREQ, + &smccc_feat->vendor_hyp_bmap); default: return kvm_hvc_call_default_allowed(func_id); } @@ -213,6 +228,9 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID: kvm_ptp_get_time(vcpu, val); break; + case ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID: + kvm_sched_get_cur_cpufreq(vcpu, val); + break; case ARM_SMCCC_TRNG_VERSION: case ARM_SMCCC_TRNG_FEATURES: case ARM_SMCCC_TRNG_GET_UUID: diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 220c8c60e021..e15f1bdcf3f1 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -112,6 +112,7 @@ /* KVM "vendor specific" services */ #define ARM_SMCCC_KVM_FUNC_FEATURES 0 #define ARM_SMCCC_KVM_FUNC_PTP 1 +#define ARM_SMCCC_KVM_FUNC_GET_CUR_CPUFREQ 64 #define ARM_SMCCC_KVM_FUNC_FEATURES_2 127 #define ARM_SMCCC_KVM_NUM_FUNCS 128 @@ -138,6 +139,12 @@ #define KVM_PTP_VIRT_COUNTER 0 #define KVM_PTP_PHYS_COUNTER 1 +#define ARM_SMCCC_VENDOR_HYP_KVM_GET_CUR_CPUFREQ_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_GET_CUR_CPUFREQ) + /* Paravirtualised time calls (defined by ARM DEN0057A) */ #define ARM_SMCCC_HV_PV_TIME_FEATURES \ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index d77aef872a0a..0a1a260243bf 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1184,6 +1184,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_S390_PROTECTED_ASYNC_DISABLE 224 #define KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP 225 #define KVM_CAP_PMU_EVENT_MASKED_EVENTS 226 +#define KVM_CAP_GET_CUR_CPUFREQ 512 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/tools/arch/arm64/include/uapi/asm/kvm.h b/tools/arch/arm64/include/uapi/asm/kvm.h index f8129c624b07..ed8b63e91bdc 100644 --- a/tools/arch/arm64/include/uapi/asm/kvm.h +++ b/tools/arch/arm64/include/uapi/asm/kvm.h @@ -367,6 +367,7 @@ enum { enum { KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT = 0, KVM_REG_ARM_VENDOR_HYP_BIT_PTP = 1, + KVM_REG_ARM_VENDOR_HYP_BIT_GET_CUR_CPUFREQ = 2, #ifdef __KERNEL__ KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT, #endif -- 2.40.0.348.gf938b09366-goog