[RFC,07/10] KVM: VMX: Introduce ioctls to set/get Sub-Page Write Protection.

Message ID	377ac04010e4d765c2e93961c7b7c87da5c53168.1506559196.git.yi.z.zhang@linux.intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> From: Zhang Yi <yi.z.zhang@linux.intel.com> To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, rkrcmar@redhat.com, Zhang Yi Z <yi.z.zhang@linux.intel.com> Subject: [PATCH RFC 07/10] KVM: VMX: Introduce ioctls to set/get Sub-Page Write Protection. Date: Sat, 14 Oct 2017 07:14:25 +0800 Message-Id: <377ac04010e4d765c2e93961c7b7c87da5c53168.1506559196.git.yi.z.zhang@linux.intel.com> In-Reply-To: <cover.1506559196.git.yi.z.zhang@linux.intel.com> References: <cover.1506559196.git.yi.z.zhang@linux.intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 5e8fdda..763cd7e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -345,6 +345,8 @@ struct kvm_mmu { void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva); void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, u64 *spte, const void *pte); + int (*get_subpages)(struct kvm *kvm, struct kvm_subpage *spp_info); + int (*set_subpages)(struct kvm *kvm, struct kvm_subpage *spp_info); hpa_t root_hpa; hpa_t sppt_root; union kvm_mmu_page_role base_role; @@ -703,6 +705,7 @@ struct kvm_lpage_info { struct kvm_arch_memory_slot { struct kvm_rmap_head *rmap[KVM_NR_PAGE_SIZES]; + u32 *subpage_wp_info; struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1]; unsigned short *gfn_track[KVM_PAGE_TRACK_MAX]; }; @@ -1063,6 +1066,8 @@ struct kvm_x86_ops { void (*cancel_hv_timer)(struct kvm_vcpu *vcpu); void (*setup_mce)(struct kvm_vcpu *vcpu); + int (*get_subpages)(struct kvm *kvm, struct kvm_subpage *spp_info); + int (*set_subpages)(struct kvm *kvm, struct kvm_subpage *spp_info); }; struct kvm_arch_async_pf { @@ -1254,6 +1259,9 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u64 error_code, void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva); void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu); +int kvm_mmu_get_subpages(struct kvm *kvm, struct kvm_subpage *spp_info); +int kvm_mmu_set_subpages(struct kvm *kvm, struct kvm_subpage *spp_info); + void kvm_enable_tdp(void); void kvm_disable_tdp(void); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 1fbe467..6c92d19 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1342,6 +1342,15 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) return sptep; } +static u32 *gfn_to_subpage_wp_info(struct kvm_memory_slot *slot, + gfn_t gfn) +{ + unsigned long idx; + + idx = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL); + return &slot->arch.subpage_wp_info[idx]; +} + #define for_each_rmap_spte(_rmap_head_, _iter_, _spte_) \ for (_spte_ = rmap_get_first(_rmap_head_, _iter_); \ _spte_; _spte_ = rmap_get_next(_iter_)) @@ -3971,6 +3980,44 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code, return 0; } +int kvm_mmu_get_subpages(struct kvm *kvm, struct kvm_subpage *spp_info) +{ + u32 *access = spp_info->access_map; + gfn_t gfn = spp_info->base_gfn; + int npages = spp_info->npages; + struct kvm_memory_slot *slot; + int i; + + for (i = 0; i < npages; i++, gfn++) { + slot = gfn_to_memslot(kvm, gfn); + if (!slot) + return -EFAULT; + access[i] = *gfn_to_subpage_wp_info(slot, gfn); + } + + return i; +} + +int kvm_mmu_set_subpages(struct kvm *kvm, struct kvm_subpage *spp_info) +{ + u32 access = spp_info->access_map[0]; + gfn_t gfn = spp_info->base_gfn; + int npages = spp_info->npages; + struct kvm_memory_slot *slot; + u32 *wp_map; + int i; + + for (i = 0; i < npages; i++, gfn++) { + slot = gfn_to_memslot(kvm, gfn); + if (!slot) + return -EFAULT; + wp_map = gfn_to_subpage_wp_info(slot, gfn); + *wp_map = access; + } + + return i; +} + static void nonpaging_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *context) { @@ -4523,6 +4570,8 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) context->get_cr3 = get_cr3; context->get_pdptr = kvm_pdptr_read; context->inject_page_fault = kvm_inject_page_fault; + context->get_subpages = kvm_x86_ops->get_subpages; + context->set_subpages = kvm_x86_ops->set_subpages; if (!is_paging(vcpu)) { context->nx = false; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index fa4f548..9116b53 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6879,6 +6879,11 @@ static __init int hardware_setup(void) kvm_x86_ops->enable_log_dirty_pt_masked = NULL; } + if (!enable_ept_spp) { + kvm_x86_ops->get_subpages = NULL; + kvm_x86_ops->set_subpages = NULL; + } + if (cpu_has_vmx_preemption_timer() && enable_preemption_timer) { u64 vmx_msr; @@ -12014,6 +12019,18 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu) ~FEATURE_CONTROL_LMCE; } +static int vmx_get_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + return kvm_get_subpages(kvm, spp_info); +} + +static int vmx_set_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + return kvm_set_subpages(kvm, spp_info); +} + static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .cpu_has_kvm_support = cpu_has_kvm_support, .disabled_by_bios = vmx_disabled_by_bios, @@ -12139,6 +12156,8 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { #endif .setup_mce = vmx_setup_mce, + .get_subpages = vmx_get_subpages, + .set_subpages = vmx_set_subpages, }; static int __init vmx_init(void) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cd17b7d..9c6fc52 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4010,6 +4010,18 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, return r; } +static int kvm_vm_ioctl_get_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + return kvm_arch_get_subpages(kvm, spp_info); +} + +static int kvm_vm_ioctl_set_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + return kvm_arch_set_subpages(kvm, spp_info); +} + long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -4270,6 +4282,40 @@ long kvm_arch_vm_ioctl(struct file *filp, r = kvm_vm_ioctl_enable_cap(kvm, &cap); break; } + case KVM_SUBPAGES_GET_ACCESS: { + struct kvm_subpage spp_info; + + r = -EFAULT; + if (copy_from_user(&spp_info, argp, sizeof(spp_info))) + goto out; + + r = -EINVAL; + if (spp_info.npages == 0 || + spp_info.npages > SUBPAGE_MAX_BITMAP) + goto out; + + r = kvm_vm_ioctl_get_subpages(kvm, &spp_info); + if (copy_to_user(argp, &spp_info, sizeof(spp_info))) { + r = -EFAULT; + goto out; + } + break; + } + case KVM_SUBPAGES_SET_ACCESS: { + struct kvm_subpage spp_info; + + r = -EFAULT; + if (copy_from_user(&spp_info, argp, sizeof(spp_info))) + goto out; + + r = -EINVAL; + if (spp_info.npages == 0 || + spp_info.npages > SUBPAGE_MAX_BITMAP) + goto out; + + r = kvm_vm_ioctl_set_subpages(kvm, &spp_info); + break; + } default: r = -ENOTTY; } @@ -8240,6 +8286,34 @@ void kvm_arch_destroy_vm(struct kvm *kvm) kvm_page_track_cleanup(kvm); } +int kvm_subpage_create_memslot(struct kvm_memory_slot *slot, + unsigned long npages) +{ + int lpages; + + lpages = gfn_to_index(slot->base_gfn + npages - 1, + slot->base_gfn, 1) + 1; + + slot->arch.subpage_wp_info = + kvzalloc(lpages * sizeof(*slot->arch.subpage_wp_info), + GFP_KERNEL); + + if (!slot->arch.subpage_wp_info) + return -ENOMEM; + + return 0; +} + +void kvm_subpage_free_memslot(struct kvm_memory_slot *free, + struct kvm_memory_slot *dont) +{ + if (!dont || free->arch.subpage_wp_info != + dont->arch.subpage_wp_info) { + kvfree(free->arch.subpage_wp_info); + free->arch.subpage_wp_info = NULL; + } +} + void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free, struct kvm_memory_slot *dont) { @@ -8261,6 +8335,7 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free, } kvm_page_track_free_memslot(free, dont); + kvm_subpage_free_memslot(free, dont); } int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, @@ -8312,8 +8387,12 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, if (kvm_page_track_create_memslot(slot, npages)) goto out_free; - return 0; + if (kvm_subpage_create_memslot(slot, npages)) + goto out_free_page_track; + return 0; +out_free_page_track: + kvm_page_track_free_memslot(slot, NULL); out_free: for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) { kvfree(slot->arch.rmap[i]); @@ -8790,6 +8869,24 @@ int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq, return kvm_x86_ops->update_pi_irte(kvm, host_irq, guest_irq, set); } +int kvm_arch_get_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + if (!kvm_x86_ops->get_subpages) + return -EINVAL; + + return kvm_x86_ops->get_subpages(kvm, spp_info); +} + +int kvm_arch_set_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + if (!kvm_x86_ops->set_subpages) + return -EINVAL; + + return kvm_x86_ops->set_subpages(kvm, spp_info); +} + bool kvm_vector_hashing_enabled(void) { return vector_hashing; diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6882538..9f33a57 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -803,6 +803,11 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu); bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu); int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu); +int kvm_get_subpages(struct kvm *kvm, struct kvm_subpage *spp_info); +int kvm_set_subpages(struct kvm *kvm, struct kvm_subpage *spp_info); +int kvm_arch_get_subpages(struct kvm *kvm, struct kvm_subpage *spp_info); +int kvm_arch_set_subpages(struct kvm *kvm, struct kvm_subpage *spp_info); + #ifndef __KVM_HAVE_ARCH_VM_ALLOC static inline struct kvm *kvm_arch_alloc_vm(void) { diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 0cd821e..fca4dc7 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -101,6 +101,15 @@ struct kvm_userspace_memory_region { __u64 userspace_addr; /* start of the userspace allocated memory */ }; +/* for KVM_SUBPAGES_GET_ACCESS and KVM_SUBPAGES_SET_ACCESS */ +#define SUBPAGE_MAX_BITMAP 128 +struct kvm_subpage { + __u64 base_gfn; + __u64 npages; + /* sub-page write-access bitmap array */ + __u32 access_map[SUBPAGE_MAX_BITMAP]; +}; + /* * The bit 0 ~ bit 15 of kvm_memory_region::flags are visible for userspace, * other bits are reserved for kvm internal use which are defined in @@ -1184,6 +1193,8 @@ struct kvm_vfio_spapr_tce { struct kvm_userspace_memory_region) #define KVM_SET_TSS_ADDR _IO(KVMIO, 0x47) #define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO, 0x48, __u64) +#define KVM_SUBPAGES_GET_ACCESS _IOR(KVMIO, 0x49, __u64) +#define KVM_SUBPAGES_SET_ACCESS _IOW(KVMIO, 0x4a, __u64) /* enable ucontrol for s390 */ struct kvm_s390_ucas_mapping { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9deb5a2..9a51ee4 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1104,6 +1104,32 @@ int kvm_get_dirty_log(struct kvm *kvm, } EXPORT_SYMBOL_GPL(kvm_get_dirty_log); +int kvm_get_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + int ret; + + mutex_lock(&kvm->slots_lock); + ret = kvm_mmu_get_subpages(kvm, spp_info); + mutex_unlock(&kvm->slots_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(kvm_get_subpages); + +int kvm_set_subpages(struct kvm *kvm, + struct kvm_subpage *spp_info) +{ + int ret; + + mutex_lock(&kvm->slots_lock); + ret = kvm_mmu_set_subpages(kvm, spp_info); + mutex_unlock(&kvm->slots_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(kvm_set_subpages); + #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT /** * kvm_get_dirty_log_protect - get a snapshot of dirty pages, and if any pages

[RFC,07/10] KVM: VMX: Introduce ioctls to set/get Sub-Page Write Protection.

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