KVM: arm64: Implement PV_SCHED_FEATURES call

euleros inclusion
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=35
CVE: NA

--------------------------------

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

Add some SMCCC compatible hypercalls for PV sched features:
  PV_SCHED_FEATURES:       0xC5000090
  PV_SCHED_IPA_INIT:       0xC5000091
  PV_SCHED_IPA_RELEASE:    0xC5000092

Also add the header file which defines the ABI for the paravirtualized
sched features we're about to add.
Signed-off-by: NZengruan Ye <yezengruan@huawei.com>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NChaochao Xing <xingchaochao@huawei.com>
Reviewed-by: NZengruan Ye <yezengruan@huawei.com>
Reviewed-by: NXiangyou Xie <xiexiangyou@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

arch/arm/include/asm/kvm_host.h

@@ -19,6 +19,7 @@
 #ifndef __ARM_KVM_HOST_H__
 #define __ARM_KVM_HOST_H__
 
+#include <linux/arm-smccc.h>
 #include <linux/types.h>
 #include <linux/kvm_types.h>
 #include <asm/cputype.h>
@@ -302,6 +303,11 @@ static inline int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 
+static inline int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu)
+{
+	return SMCCC_RET_NOT_SUPPORTED;
+}
+
 void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);

arch/arm64/include/asm/kvm_host.h

@@ -430,6 +430,8 @@ void handle_exit_early(struct kvm_vcpu *vcpu, struct kvm_run *run,
 int kvm_perf_init(void);
 int kvm_perf_teardown(void);
 
+int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu);
+
 void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);

arch/arm64/include/asm/pvsched-abi.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright(c) 2019 Huawei Technologies Co., Ltd
+ * Author: Zengruan Ye <yezengruan@huawei.com>
+ */
+
+#ifndef __ASM_PVSCHED_ABI_H
+#define __ASM_PVSCHED_ABI_H
+
+struct pvsched_vcpu_state {
+	__le32 preempted;
+	/* Structure must be 64 byte aligned, pad to that size */
+	u8 padding[60];
+} __packed;
+
+#endif

arch/arm64/kvm/Makefile

@@ -16,6 +16,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/e
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arm.o $(KVM)/arm/mmu.o $(KVM)/arm/mmio.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/psci.o $(KVM)/arm/perf.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hypercalls.o
+kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/pvsched.o
 
 kvm-$(CONFIG_KVM_ARM_HOST) += inject_fault.o regmap.o va_layout.o
 kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o

include/linux/arm-smccc.h

@@ -54,6 +54,7 @@
 #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
@@ -356,5 +357,24 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
 	method;								\
 	})
 
+/* Paravirtualised sched calls */
+#define ARM_SMCCC_HV_PV_SCHED_FEATURES				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
+			   ARM_SMCCC_SMC_64,			\
+			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
+			   0x90)
+
+#define ARM_SMCCC_HV_PV_SCHED_IPA_INIT				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
+			   ARM_SMCCC_SMC_64,			\
+			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
+			   0x91)
+
+#define ARM_SMCCC_HV_PV_SCHED_IPA_RELEASE			\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
+			   ARM_SMCCC_SMC_64,			\
+			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
+			   0x92)
+
 #endif /*__ASSEMBLY__*/
 #endif /*__LINUX_ARM_SMCCC_H*/

virt/kvm/arm/hypercalls.c

@@ -40,8 +40,14 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 				break;
 			}
 			break;
+		case ARM_SMCCC_HV_PV_SCHED_FEATURES:
+			val = SMCCC_RET_SUCCESS;
+			break;
 		}
 		break;
+	case ARM_SMCCC_HV_PV_SCHED_FEATURES:
+		val = kvm_hypercall_pvsched_features(vcpu);
+		break;
 	default:
 		return kvm_psci_call(vcpu);
 	}

virt/kvm/arm/pvsched.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright(c) 2019 Huawei Technologies Co., Ltd
+ * Author: Zengruan Ye <yezengruan@huawei.com>
+ */
+
+#include <linux/arm-smccc.h>
+
+#include <kvm/arm_hypercalls.h>
+
+int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu)
+{
+	u32 feature = smccc_get_arg1(vcpu);
+	int val = SMCCC_RET_NOT_SUPPORTED;
+
+	switch (feature) {
+	case ARM_SMCCC_HV_PV_SCHED_FEATURES:
+		val = SMCCC_RET_SUCCESS;
+		break;
+	}
+
+	return val;
+}