From: eillon <yezhenyu2@huawei.com> In ARM64, the buffer size corresponding to the HDBSS feature is configurable. Therefore, we cannot enable the HDBSS feature during KVM initialization, but we should enable it when triggering a live migration, where the buffer size can be configured by the user. The KVM_CAP_ARM_HW_DIRTY_STATE_TRACK ioctl is added to enable/disable this feature. Users (such as qemu) can invoke the ioctl to enable HDBSS at the beginning of the migration and disable the feature by invoking the ioctl again at the end of the migration with size set to 0. Signed-off-by: eillon <yezhenyu2@huawei.com> --- arch/arm64/include/asm/cpufeature.h | 12 +++++ arch/arm64/include/asm/kvm_host.h | 5 +++ arch/arm64/include/asm/kvm_mmu.h | 12 +++++ arch/arm64/include/asm/sysreg.h | 12 +++++ arch/arm64/kvm/arm.c | 70 +++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/vhe/switch.c | 1 + arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 2 + arch/arm64/kvm/mmu.c | 3 ++ arch/arm64/kvm/reset.c | 7 +++ include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 2 + tools/include/uapi/linux/kvm.h | 2 + 12 files changed, 129 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index d68307a50d13..d2b9771b4a82 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -752,6 +752,18 @@ static __always_inline bool system_supports_fpsimd(void) return !cpus_have_const_cap(ARM64_HAS_NO_FPSIMD); } +static inline bool system_supports_hdbss(void) +{ + u64 mmfr1; + u32 val; + + mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + val = cpuid_feature_extract_unsigned_field(mmfr1, + ID_AA64MMFR1_EL1_HAFDBS_SHIFT); + + return val == ID_AA64MMFR1_EL1_HAFDBS_HDBSS; +} + static inline bool system_uses_hw_pan(void) { return IS_ENABLED(CONFIG_ARM64_PAN) && diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index ac4e59256f8e..51f99f3d824a 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -641,6 +641,11 @@ struct kvm_vcpu_arch { #ifdef CONFIG_HISI_VIRTCCA_HOST struct virtcca_cvm_tec tec; #endif + /* HDBSS registers info */ + struct { + u64 br_el2; + u64 prod_el2; + } hdbss; }; /* diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index d698ce35deb8..a76bc71010e7 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -310,6 +310,18 @@ static __always_inline void __load_stage2(struct kvm_s2_mmu *mmu, asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT)); } +static __always_inline void __load_hdbss(struct kvm_vcpu *vcpu) +{ + if (!vcpu->kvm->enable_hdbss) + return; + + write_sysreg_s(vcpu->arch.hdbss.br_el2, SYS_HDBSSBR_EL2); + write_sysreg_s(vcpu->arch.hdbss.prod_el2, SYS_HDBSSPROD_EL2); + + dsb(sy); + isb(); +} + static inline struct kvm *kvm_s2_mmu_to_kvm(struct kvm_s2_mmu *mmu) { return container_of(mmu->arch, struct kvm, arch); diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 435634a703c6..8494aac11824 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1031,6 +1031,18 @@ #define PIRx_ELx_PERM(idx, perm) ((perm) << ((idx) * 4)) +/* + * Definitions for the HDBSS feature + */ +#define HDBSS_MAX_SIZE HDBSSBR_EL2_SZ_2MB + +#define HDBSSBR_EL2(baddr, sz) (((baddr) & GENMASK(55, 12 + sz)) | \ + ((sz) << HDBSSBR_EL2_SZ_SHIFT)) +#define HDBSSBR_BADDR(br) ((br) & GENMASK(55, (12 + HDBSSBR_SZ(br)))) +#define HDBSSBR_SZ(br) (((br) & HDBSSBR_EL2_SZ_MASK) >> HDBSSBR_EL2_SZ_SHIFT) + +#define HDBSSPROD_IDX(prod) (((prod) & HDBSSPROD_EL2_INDEX_MASK) >> HDBSSPROD_EL2_INDEX_SHIFT) + #define ARM64_FEATURE_FIELD_BITS 4 /* Defined for compatibility only, do not add new users. */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 5ba336d1efad..d72c6c72e60a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -129,6 +129,70 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; } +static int kvm_cap_arm_enable_hdbss(struct kvm *kvm, + struct kvm_enable_cap *cap) +{ + unsigned long i; + struct kvm_vcpu *vcpu; + struct page *hdbss_pg; + int size = cap->args[0]; + + if (!system_supports_hdbss()) { + kvm_err("This system does not support HDBSS!\n"); + return -EINVAL; + } + + if (size < 0 || size > HDBSS_MAX_SIZE) { + kvm_err("Invalid HDBSS buffer size: %d!\n", size); + return -EINVAL; + } + + /* Enable the HDBSS feature if size > 0, otherwise disable it. */ + if (size) { + kvm->enable_hdbss = true; + kvm->arch.vtcr |= VTCR_EL2_HD | VTCR_EL2_HDBSS; + + kvm_for_each_vcpu(i, vcpu, kvm) { + hdbss_pg = alloc_pages(GFP_KERNEL, size); + if (!hdbss_pg) { + kvm_err("Alloc HDBSS buffer failed!\n"); + return -EINVAL; + } + + vcpu->arch.hdbss.br_el2 = HDBSSBR_EL2(page_to_phys(hdbss_pg), size); + vcpu->arch.hdbss.prod_el2 = 0; + + /* + * We should kick vcpus out of guest mode here to + * load new vtcr value to vtcr_el2 register when + * re-enter guest mode. + */ + kvm_vcpu_kick(vcpu); + } + + kvm_info("Enable HDBSS success, HDBSS buffer size: %d\n", size); + } else if (kvm->enable_hdbss) { + kvm->arch.vtcr &= ~(VTCR_EL2_HD | VTCR_EL2_HDBSS); + + kvm_for_each_vcpu(i, vcpu, kvm) { + /* Kick vcpus to flush hdbss buffer. */ + kvm_vcpu_kick(vcpu); + + hdbss_pg = phys_to_page(HDBSSBR_BADDR(vcpu->arch.hdbss.br_el2)); + if (hdbss_pg) + __free_pages(hdbss_pg, HDBSSBR_SZ(vcpu->arch.hdbss.br_el2)); + + vcpu->arch.hdbss.br_el2 = 0; + vcpu->arch.hdbss.prod_el2 = 0; + } + + kvm->enable_hdbss = false; + kvm_info("Disable HDBSS success\n"); + } + + return 0; +} + int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { @@ -183,6 +247,9 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, r = kvm_cvm_enable_cap(kvm, cap); break; #endif + case KVM_CAP_ARM_HW_DIRTY_STATE_TRACK: + r = kvm_cap_arm_enable_hdbss(kvm, cap); + break; default: r = -EINVAL; break; @@ -436,6 +503,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) r = static_key_enabled(&virtcca_cvm_is_available); break; #endif + case KVM_CAP_ARM_HW_DIRTY_STATE_TRACK: + r = system_supports_hdbss(); + break; default: r = 0; } diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 821e366b54f2..3d6f5891010e 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -225,6 +225,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) * __activate_traps clear HCR_EL2.TGE (among other things). */ __load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch); + __load_hdbss(vcpu); __activate_traps(vcpu); __kvm_adjust_pc(vcpu); diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c index 5cb4b70e0aef..236d07c1b0b8 100644 --- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c @@ -92,6 +92,8 @@ void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu) __sysreg_restore_el1_state(guest_ctxt); __mpam_guest_load(); + __load_hdbss(vcpu); + vcpu_set_flag(vcpu, SYSREGS_ON_CPU); activate_traps_vhe_load(vcpu); diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 65554248cb7f..ea7ab43154cc 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1586,6 +1586,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (writable) prot |= KVM_PGTABLE_PROT_W; + if (kvm->enable_hdbss && logging_active) + prot |= KVM_PGTABLE_PROT_DBM; + if (exec_fault) prot |= KVM_PGTABLE_PROT_X; diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index d38e74db97c2..806080553bc1 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -162,6 +162,7 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu) { void *sve_state = vcpu->arch.sve_state; + struct page *hdbss_pg; kvm_vcpu_unshare_task_fp(vcpu); kvm_unshare_hyp(vcpu, vcpu + 1); @@ -173,6 +174,12 @@ void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu) if (vcpu_is_tec(vcpu)) kvm_destroy_tec(vcpu); #endif + + if (vcpu->arch.hdbss.br_el2) { + hdbss_pg = phys_to_page(HDBSSBR_BADDR(vcpu->arch.hdbss.br_el2)); + if (hdbss_pg) + __free_pages(hdbss_pg, HDBSSBR_SZ(vcpu->arch.hdbss.br_el2)); + } } static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index c848eb86c556..7235e88c726f 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -842,6 +842,7 @@ struct kvm { struct notifier_block pm_notifier; #endif char stats_id[KVM_STATS_NAME_SIZE]; + bool enable_hdbss; }; #define kvm_err(fmt, ...) \ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 1f67e4d6ff7b..52695dea196e 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1210,6 +1210,8 @@ struct kvm_ppc_resize_hpt { /* support request to inject secret to CSV3 guest */ #define KVM_CAP_HYGON_COCO_EXT_CSV3_INJ_SECRET (1 << 2) +#define KVM_CAP_ARM_HW_DIRTY_STATE_TRACK 502 + #define KVM_CAP_ARM_VIRT_MSI_BYPASS 799 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h index 3a2b617b6429..bd1a496b5448 100644 --- a/tools/include/uapi/linux/kvm.h +++ b/tools/include/uapi/linux/kvm.h @@ -1193,6 +1193,8 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE 228 #define KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES 229 +#define KVM_CAP_ARM_HW_DIRTY_STATE_TRACK 502 + #ifdef KVM_CAP_IRQ_ROUTING struct kvm_irq_routing_irqchip { -- 2.39.3