From nobody Thu Sep 18 21:59:21 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass header.i=@intel.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=linux.intel.com ARC-Seal: i=1; a=rsa-sha256; t=1669962077; cv=none; d=zohomail.com; s=zohoarc; b=dEUqum7EqAw1EBR5oRfB0/2hnUckSC+Dm3lgd3mjJgfiXcrvAf+zIihdzCBSSKSXluZjllezMmTuQVSX8JXuE4P4xqx5edV4F3fLlMbEbLFtftgYq2rTa2l+/F22l/kkS26SeTxJSOMB3bnpTvh3cRvcjcmVFSN4F8Bem2cbttI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1669962077; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=LitJ1Pcae3Q2I4e/+ChynXp7xxO2JKX2XlQWHV4NnwA=; b=ltyCkuYJZxodDrfyUApvfYfS+x5O+OMmcXBwBiaHPHKBhzJikvzPk9fayRYplfoOg5RxkAbpL7KNNakgvIHzZdMHmA9wRarTm+2Qko8LclDpwDb7yDMbdhG0TYTGLXyvw1JAxZT+T6a4lZDgyxHWyl7NJWaIRwAQ1qEyCRDVf7A= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=@intel.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1669962077170381.40062774734156; Thu, 1 Dec 2022 22:21:17 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1p0zP2-0005EF-6s; Fri, 02 Dec 2022 01:20:04 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p0zOz-0005CY-0r for qemu-devel@nongnu.org; Fri, 02 Dec 2022 01:20:01 -0500 Received: from mga07.intel.com ([134.134.136.100]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1p0zOw-00084m-5t for qemu-devel@nongnu.org; Fri, 02 Dec 2022 01:20:00 -0500 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Dec 2022 22:19:56 -0800 Received: from chaop.bj.intel.com ([10.240.193.75]) by FMSMGA003.fm.intel.com with ESMTP; 01 Dec 2022 22:19:45 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669961998; x=1701497998; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=88Pkdv7kTSmlac+dsvaEbFSp3wXt4d9KWmWXJPdj1wM=; b=hEHxJDl39us7QWLRmlKCx21UZ/xi3nMf/KGCAZs7MdcqmNpk6mR4H9Go ozBFV6o9cvue2MIdlSGLdBmuJBuyeduBmEXqeqQKpgVfgNBb3rr8pWW8c 33wKlqux2yCaW73kR0iqwkAwBLAIx25/XMUDlwyKzOaX86p7H1DTa0XJJ luLDHA4avWl2P3YIXK8oyiPbcKQSFnwr/MiFDnp9DI/cS4ukbMJkuzdpl LoB4f2dK6I/IysyyCwb3x3+P/c7NmMF7dMU3NV//0xoEVjtgAp1MAqHbv qL7UPwwmqNhdDSypM7agcJlR5s6Mw9hwRxmAWSR1aZrqfQuOZSly3YxvB Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10548"; a="380170721" X-IronPort-AV: E=Sophos;i="5.96,210,1665471600"; d="scan'208";a="380170721" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10548"; a="733698820" X-IronPort-AV: E=Sophos;i="5.96,210,1665471600"; d="scan'208";a="733698820" From: Chao Peng To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, qemu-devel@nongnu.org Cc: Paolo Bonzini , Jonathan Corbet , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Arnd Bergmann , Naoya Horiguchi , Miaohe Lin , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Shuah Khan , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , Chao Peng , "Kirill A . Shutemov" , luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com, aarcange@redhat.com, ddutile@redhat.com, dhildenb@redhat.com, Quentin Perret , tabba@google.com, Michael Roth , mhocko@suse.com, wei.w.wang@intel.com Subject: [PATCH v10 9/9] KVM: Enable and expose KVM_MEM_PRIVATE Date: Fri, 2 Dec 2022 14:13:47 +0800 Message-Id: <20221202061347.1070246-10-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221202061347.1070246-1-chao.p.peng@linux.intel.com> References: <20221202061347.1070246-1-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=134.134.136.100; envelope-from=chao.p.peng@linux.intel.com; helo=mga07.intel.com X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @intel.com) X-ZM-MESSAGEID: 1669962077970100001 Content-Type: text/plain; charset="utf-8" Register/unregister private memslot to fd-based memory backing store restrictedmem and implement the callbacks for restrictedmem_notifier: - invalidate_start()/invalidate_end() to zap the existing memory mappings in the KVM page table. - error() to request KVM_REQ_MEMORY_MCE and later exit to userspace with KVM_EXIT_SHUTDOWN. Expose KVM_MEM_PRIVATE for memslot and KVM_MEMORY_ATTRIBUTE_PRIVATE for KVM_GET_SUPPORTED_MEMORY_ATTRIBUTES to userspace but either are controlled by kvm_arch_has_private_mem() which should be rewritten by architecture code. Co-developed-by: Yu Zhang Signed-off-by: Yu Zhang Signed-off-by: Chao Peng Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/x86.c | 13 +++ include/linux/kvm_host.h | 3 + virt/kvm/kvm_main.c | 179 +++++++++++++++++++++++++++++++- 4 files changed, 191 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_hos= t.h index 7772ab37ac89..27ef31133352 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -114,6 +114,7 @@ KVM_ARCH_REQ_FLAGS(31, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) #define KVM_REQ_HV_TLB_FLUSH \ KVM_ARCH_REQ_FLAGS(32, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) +#define KVM_REQ_MEMORY_MCE KVM_ARCH_REQ(33) =20 #define CR0_RESERVED_BITS \ (~(unsigned long)(X86_CR0_PE | X86_CR0_MP | X86_CR0_EM | X86_CR0_TS \ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5aefcff614d2..c67e22f3e2ee 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6587,6 +6587,13 @@ int kvm_arch_pm_notifier(struct kvm *kvm, unsigned l= ong state) } #endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */ =20 +#ifdef CONFIG_HAVE_KVM_RESTRICTED_MEM +void kvm_arch_memory_mce(struct kvm *kvm) +{ + kvm_make_all_cpus_request(kvm, KVM_REQ_MEMORY_MCE); +} +#endif + static int kvm_vm_ioctl_get_clock(struct kvm *kvm, void __user *argp) { struct kvm_clock_data data =3D { 0 }; @@ -10357,6 +10364,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) =20 if (kvm_check_request(KVM_REQ_UPDATE_CPU_DIRTY_LOGGING, vcpu)) static_call(kvm_x86_update_cpu_dirty_logging)(vcpu); + + if (kvm_check_request(KVM_REQ_MEMORY_MCE, vcpu)) { + vcpu->run->exit_reason =3D KVM_EXIT_SHUTDOWN; + r =3D 0; + goto out; + } } =20 if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win || diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 153842bb33df..f032d878e034 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -590,6 +590,7 @@ struct kvm_memory_slot { struct file *restricted_file; loff_t restricted_offset; struct restrictedmem_notifier notifier; + struct kvm *kvm; }; =20 static inline bool kvm_slot_can_be_private(const struct kvm_memory_slot *s= lot) @@ -2363,6 +2364,8 @@ static inline int kvm_restricted_mem_get_pfn(struct k= vm_memory_slot *slot, *pfn =3D page_to_pfn(page); return ret; } + +void kvm_arch_memory_mce(struct kvm *kvm); #endif /* CONFIG_HAVE_KVM_RESTRICTED_MEM */ =20 #endif diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e107afea32f0..ac835fc77273 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -936,6 +936,121 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) =20 #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ =20 +#ifdef CONFIG_HAVE_KVM_RESTRICTED_MEM +static bool restrictedmem_range_is_valid(struct kvm_memory_slot *slot, + pgoff_t start, pgoff_t end, + gfn_t *gfn_start, gfn_t *gfn_end) +{ + unsigned long base_pgoff =3D slot->restricted_offset >> PAGE_SHIFT; + + if (start > base_pgoff) + *gfn_start =3D slot->base_gfn + start - base_pgoff; + else + *gfn_start =3D slot->base_gfn; + + if (end < base_pgoff + slot->npages) + *gfn_end =3D slot->base_gfn + end - base_pgoff; + else + *gfn_end =3D slot->base_gfn + slot->npages; + + if (*gfn_start >=3D *gfn_end) + return false; + + return true; +} + +static void kvm_restrictedmem_invalidate_begin(struct restrictedmem_notifi= er *notifier, + pgoff_t start, pgoff_t end) +{ + struct kvm_memory_slot *slot =3D container_of(notifier, + struct kvm_memory_slot, + notifier); + struct kvm *kvm =3D slot->kvm; + gfn_t gfn_start, gfn_end; + struct kvm_gfn_range gfn_range; + int idx; + + if (!restrictedmem_range_is_valid(slot, start, end, + &gfn_start, &gfn_end)) + return; + + gfn_range.start =3D gfn_start; + gfn_range.end =3D gfn_end; + gfn_range.slot =3D slot; + gfn_range.pte =3D __pte(0); + gfn_range.may_block =3D true; + + idx =3D srcu_read_lock(&kvm->srcu); + KVM_MMU_LOCK(kvm); + + kvm_mmu_invalidate_begin(kvm); + kvm_mmu_invalidate_range_add(kvm, gfn_start, gfn_end); + if (kvm_unmap_gfn_range(kvm, &gfn_range)) + kvm_flush_remote_tlbs(kvm); + + KVM_MMU_UNLOCK(kvm); + srcu_read_unlock(&kvm->srcu, idx); +} + +static void kvm_restrictedmem_invalidate_end(struct restrictedmem_notifier= *notifier, + pgoff_t start, pgoff_t end) +{ + struct kvm_memory_slot *slot =3D container_of(notifier, + struct kvm_memory_slot, + notifier); + struct kvm *kvm =3D slot->kvm; + gfn_t gfn_start, gfn_end; + + if (!restrictedmem_range_is_valid(slot, start, end, + &gfn_start, &gfn_end)) + return; + + KVM_MMU_LOCK(kvm); + kvm_mmu_invalidate_end(kvm); + KVM_MMU_UNLOCK(kvm); +} + +static void kvm_restrictedmem_error(struct restrictedmem_notifier *notifie= r, + pgoff_t start, pgoff_t end) +{ + struct kvm_memory_slot *slot =3D container_of(notifier, + struct kvm_memory_slot, + notifier); + kvm_arch_memory_mce(slot->kvm); +} + +static struct restrictedmem_notifier_ops kvm_restrictedmem_notifier_ops = =3D { + .invalidate_start =3D kvm_restrictedmem_invalidate_begin, + .invalidate_end =3D kvm_restrictedmem_invalidate_end, + .error =3D kvm_restrictedmem_error, +}; + +static inline void kvm_restrictedmem_register(struct kvm_memory_slot *slot) +{ + slot->notifier.ops =3D &kvm_restrictedmem_notifier_ops; + restrictedmem_register_notifier(slot->restricted_file, &slot->notifier); +} + +static inline void kvm_restrictedmem_unregister(struct kvm_memory_slot *sl= ot) +{ + restrictedmem_unregister_notifier(slot->restricted_file, + &slot->notifier); +} + +#else /* !CONFIG_HAVE_KVM_RESTRICTED_MEM */ + +static inline void kvm_restrictedmem_register(struct kvm_memory_slot *slot) +{ + WARN_ON_ONCE(1); +} + +static inline void kvm_restrictedmem_unregister(struct kvm_memory_slot *sl= ot) +{ + WARN_ON_ONCE(1); +} + +#endif /* CONFIG_HAVE_KVM_RESTRICTED_MEM */ + #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER static int kvm_pm_notifier_call(struct notifier_block *bl, unsigned long state, @@ -980,6 +1095,11 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memor= y_slot *memslot) /* This does not remove the slot from struct kvm_memslots data structures = */ static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { + if (slot->flags & KVM_MEM_PRIVATE) { + kvm_restrictedmem_unregister(slot); + fput(slot->restricted_file); + } + kvm_destroy_dirty_bitmap(slot); =20 kvm_arch_free_memslot(kvm, slot); @@ -1551,10 +1671,14 @@ static void kvm_replace_memslot(struct kvm *kvm, } } =20 -static int check_memory_region_flags(const struct kvm_user_mem_region *mem) +static int check_memory_region_flags(struct kvm *kvm, + const struct kvm_user_mem_region *mem) { u32 valid_flags =3D KVM_MEM_LOG_DIRTY_PAGES; =20 + if (kvm_arch_has_private_mem(kvm)) + valid_flags |=3D KVM_MEM_PRIVATE; + #ifdef __KVM_HAVE_READONLY_MEM valid_flags |=3D KVM_MEM_READONLY; #endif @@ -1630,6 +1754,9 @@ static int kvm_prepare_memory_region(struct kvm *kvm, { int r; =20 + if (change =3D=3D KVM_MR_CREATE && new->flags & KVM_MEM_PRIVATE) + kvm_restrictedmem_register(new); + /* * If dirty logging is disabled, nullify the bitmap; the old bitmap * will be freed on "commit". If logging is enabled in both old and @@ -1658,6 +1785,9 @@ static int kvm_prepare_memory_region(struct kvm *kvm, if (r && new && new->dirty_bitmap && (!old || !old->dirty_bitmap)) kvm_destroy_dirty_bitmap(new); =20 + if (r && change =3D=3D KVM_MR_CREATE && new->flags & KVM_MEM_PRIVATE) + kvm_restrictedmem_unregister(new); + return r; } =20 @@ -1963,7 +2093,7 @@ int __kvm_set_memory_region(struct kvm *kvm, int as_id, id; int r; =20 - r =3D check_memory_region_flags(mem); + r =3D check_memory_region_flags(kvm, mem); if (r) return r; =20 @@ -1982,6 +2112,10 @@ int __kvm_set_memory_region(struct kvm *kvm, !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL; + if (mem->flags & KVM_MEM_PRIVATE && + (mem->restricted_offset & (PAGE_SIZE - 1) || + mem->restricted_offset > U64_MAX - mem->memory_size)) + return -EINVAL; if (as_id >=3D KVM_ADDRESS_SPACE_NUM || id >=3D KVM_MEM_SLOTS_NUM) return -EINVAL; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) @@ -2020,6 +2154,9 @@ int __kvm_set_memory_region(struct kvm *kvm, if ((kvm->nr_memslot_pages + npages) < kvm->nr_memslot_pages) return -EINVAL; } else { /* Modify an existing slot. */ + /* Private memslots are immutable, they can only be deleted. */ + if (mem->flags & KVM_MEM_PRIVATE) + return -EINVAL; if ((mem->userspace_addr !=3D old->userspace_addr) || (npages !=3D old->npages) || ((mem->flags ^ old->flags) & KVM_MEM_READONLY)) @@ -2048,10 +2185,28 @@ int __kvm_set_memory_region(struct kvm *kvm, new->npages =3D npages; new->flags =3D mem->flags; new->userspace_addr =3D mem->userspace_addr; + if (mem->flags & KVM_MEM_PRIVATE) { + new->restricted_file =3D fget(mem->restricted_fd); + if (!new->restricted_file || + !file_is_restrictedmem(new->restricted_file)) { + r =3D -EINVAL; + goto out; + } + new->restricted_offset =3D mem->restricted_offset; + } + + new->kvm =3D kvm; =20 r =3D kvm_set_memslot(kvm, old, new, change); if (r) - kfree(new); + goto out; + + return 0; + +out: + if (new->restricted_file) + fput(new->restricted_file); + kfree(new); return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region); @@ -2351,6 +2506,8 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *k= vm, #ifdef CONFIG_HAVE_KVM_MEMORY_ATTRIBUTES static u64 kvm_supported_mem_attributes(struct kvm *kvm) { + if (kvm_arch_has_private_mem(kvm)) + return KVM_MEMORY_ATTRIBUTE_PRIVATE; return 0; } =20 @@ -4822,16 +4979,28 @@ static long kvm_vm_ioctl(struct file *filp, } case KVM_SET_USER_MEMORY_REGION: { struct kvm_user_mem_region mem; - unsigned long size =3D sizeof(struct kvm_userspace_memory_region); + unsigned int flags_offset =3D offsetof(typeof(mem), flags); + unsigned long size; + u32 flags; =20 kvm_sanity_check_user_mem_region_alias(); =20 + memset(&mem, 0, sizeof(mem)); + r =3D -EFAULT; + if (get_user(flags, (u32 __user *)(argp + flags_offset))) + goto out; + + if (flags & KVM_MEM_PRIVATE) + size =3D sizeof(struct kvm_userspace_memory_region_ext); + else + size =3D sizeof(struct kvm_userspace_memory_region); + if (copy_from_user(&mem, argp, size)) goto out; =20 r =3D -EINVAL; - if (mem.flags & KVM_MEM_PRIVATE) + if ((flags ^ mem.flags) & KVM_MEM_PRIVATE) goto out; =20 r =3D kvm_vm_ioctl_set_memory_region(kvm, &mem); --=20 2.25.1