From: Zengruan Ye yezengruan@huawei.com
virt inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8WMFU CVE: NA
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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: Zengruan Ye yezengruan@huawei.com Signed-off-by: lishusen lishusen2@huawei.com
1
Signed-off-by: lishusen lishusen2@huawei.com --- arch/arm64/Kconfig | 11 +++++++++++ arch/arm64/configs/openeuler_defconfig | 1 + arch/arm64/include/asm/kvm_host.h | 9 +++++++++ arch/arm64/include/asm/pvsched-abi.h | 16 ++++++++++++++++ arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/hypercalls.c | 6 ++++++ arch/arm64/kvm/pvsched.c | 26 ++++++++++++++++++++++++++ include/linux/arm-smccc.h | 19 +++++++++++++++++++ 8 files changed, 89 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/pvsched-abi.h create mode 100644 arch/arm64/kvm/pvsched.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 67bc2ad13453..425114ca1cc7 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1549,6 +1549,17 @@ config PARAVIRT under a hypervisor, potentially improving performance significantly over full virtualization.
+config PARAVIRT_SCHED + bool "Paravirtualization layer for sched" + depends on PARAVIRT + help + This supports the vCPU preemption check to enhance lock performance on + overcommitted hosts (more runnable vCPUs than physical CPUs in the + system) as doing busy waits for preempted vCPUs will hurt system + performance far worse than early yielding. + + If you are unsure how to answer this question, answer Y. + config PARAVIRT_TIME_ACCOUNTING bool "Paravirtual steal time accounting" select PARAVIRT diff --git a/arch/arm64/configs/openeuler_defconfig b/arch/arm64/configs/openeuler_defconfig index e1cf25de0102..a61409f40022 100644 --- a/arch/arm64/configs/openeuler_defconfig +++ b/arch/arm64/configs/openeuler_defconfig @@ -469,6 +469,7 @@ CONFIG_SCHED_HRTICK=y CONFIG_ARCH_SPARSEMEM_ENABLE=y CONFIG_HW_PERF_EVENTS=y CONFIG_PARAVIRT=y +CONFIG_PARAVIRT_SCHED=y CONFIG_PARAVIRT_TIME_ACCOUNTING=y CONFIG_ARCH_SUPPORTS_KEXEC=y CONFIG_ARCH_SUPPORTS_KEXEC_FILE=y diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 993b60d7219d..1d046ebae9c3 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1051,6 +1051,15 @@ static inline bool kvm_arm_is_pvtime_enabled(struct kvm_vcpu_arch *vcpu_arch) return (vcpu_arch->steal.base != INVALID_GPA); }
+#ifdef CONFIG_PARAVIRT_SCHED +long kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu); +#else +static inline long kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu) +{ + return 0; +} +#endif + void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); diff --git a/arch/arm64/include/asm/pvsched-abi.h b/arch/arm64/include/asm/pvsched-abi.h new file mode 100644 index 000000000000..80e50e7a1a31 --- /dev/null +++ b/arch/arm64/include/asm/pvsched-abi.h @@ -0,0 +1,16 @@ +/* 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 diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 826a05d072d7..fe63a91a4c54 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -10,7 +10,7 @@ include $(srctree)/virt/kvm/Makefile.kvm obj-$(CONFIG_KVM) += kvm.o obj-$(CONFIG_KVM) += hyp/
-kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \ +kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o pvsched.o \ inject_fault.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o stacktrace.o \ vgic-sys-reg-v3.o fpsimd.o pkvm.o \ diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 7fb4df0456de..a7c4090a5dbc 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -332,6 +332,9 @@ int kvm_smccc_call_handler(struct kvm_vcpu *vcpu) &smccc_feat->std_hyp_bmap)) val[0] = SMCCC_RET_SUCCESS; break; + case ARM_SMCCC_HV_PV_SCHED_FEATURES: + val[0] = SMCCC_RET_SUCCESS; + break; } break; case ARM_SMCCC_HV_PV_TIME_FEATURES: @@ -342,6 +345,9 @@ int kvm_smccc_call_handler(struct kvm_vcpu *vcpu) if (gpa != INVALID_GPA) val[0] = gpa; break; + case ARM_SMCCC_HV_PV_SCHED_FEATURES: + val[0] = kvm_hypercall_pvsched_features(vcpu); + break; case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID: val[0] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0; val[1] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1; diff --git a/arch/arm64/kvm/pvsched.c b/arch/arm64/kvm/pvsched.c new file mode 100644 index 000000000000..b54237707ec5 --- /dev/null +++ b/arch/arm64/kvm/pvsched.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright(c) 2019 Huawei Technologies Co., Ltd + * Author: Zengruan Ye yezengruan@huawei.com + */ + +#ifdef CONFIG_PARAVIRT_SCHED +#include <linux/arm-smccc.h> + +#include <kvm/arm_hypercalls.h> + +long kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu) +{ + u32 feature = smccc_get_arg1(vcpu); + long val = SMCCC_RET_NOT_SUPPORTED; + + switch (feature) { + case ARM_SMCCC_HV_PV_SCHED_FEATURES: + val = SMCCC_RET_SUCCESS; + break; + } + + return val; +} +#endif /* CONFIG_PARAVIRT_SCHED */ + diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 083f85653716..daab363d31ae 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -577,5 +577,24 @@ 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*/