From: Chao Peng <chao.p.peng@linux.intel.com> To: Sean Christopherson <seanjc@google.com> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>, Jonathan Corbet <corbet@lwn.net>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>, Hugh Dickins <hughd@google.com>, Jeff Layton <jlayton@kernel.org>, "J . Bruce Fields" <bfields@fieldses.org>, Andrew Morton <akpm@linux-foundation.org>, Mike Rapoport <rppt@kernel.org>, Steven Price <steven.price@arm.com>, "Maciej S . Szmigiero" <mail@maciej.szmigiero.name>, Vlastimil Babka <vbabka@suse.cz>, Vishal Annapurve <vannapurve@google.com>, Yu Zhang <yu.c.zhang@linux.intel.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: Re: [PATCH v5 11/13] KVM: Zap existing KVM mappings when pages changed in the private fd Date: Tue, 12 Apr 2022 20:43:25 +0800 [thread overview] Message-ID: <20220412124325.GB8013@chaop.bj.intel.com> (raw) In-Reply-To: <YkNcmGsOw4MThaym@google.com> On Tue, Mar 29, 2022 at 07:23:04PM +0000, Sean Christopherson wrote: > On Thu, Mar 10, 2022, Chao Peng wrote: > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > > index 67349421eae3..52319f49d58a 100644 > > --- a/virt/kvm/kvm_main.c > > +++ b/virt/kvm/kvm_main.c > > @@ -841,8 +841,43 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) > > #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ > > > > #ifdef CONFIG_MEMFILE_NOTIFIER > > +static void kvm_memfile_notifier_handler(struct memfile_notifier *notifier, > > + pgoff_t start, pgoff_t end) > > +{ > > + int idx; > > + struct kvm_memory_slot *slot = container_of(notifier, > > + struct kvm_memory_slot, > > + notifier); > > + struct kvm_gfn_range gfn_range = { > > + .slot = slot, > > + .start = start - (slot->private_offset >> PAGE_SHIFT), > > + .end = end - (slot->private_offset >> PAGE_SHIFT), > > + .may_block = true, > > + }; > > + struct kvm *kvm = slot->kvm; > > + > > + gfn_range.start = max(gfn_range.start, slot->base_gfn); > > + gfn_range.end = min(gfn_range.end, slot->base_gfn + slot->npages); > > + > > + if (gfn_range.start >= gfn_range.end) > > + return; > > + > > + idx = srcu_read_lock(&kvm->srcu); > > + KVM_MMU_LOCK(kvm); > > + kvm_unmap_gfn_range(kvm, &gfn_range); > > + kvm_flush_remote_tlbs(kvm); > > This should check the result of kvm_unmap_gfn_range() and flush only if necessary. Yep. > > kvm->mmu_notifier_seq needs to be incremented, otherwise KVM will incorrectly > install a SPTE if the mapping is zapped between retrieving the pfn in faultin and > installing it after acquire mmu_lock. Good catch. Chao > > > > + KVM_MMU_UNLOCK(kvm); > > + srcu_read_unlock(&kvm->srcu, idx); > > +} > > + > > +static struct memfile_notifier_ops kvm_memfile_notifier_ops = { > > + .invalidate = kvm_memfile_notifier_handler, > > + .fallocate = kvm_memfile_notifier_handler, > > +}; > > + > > static inline int kvm_memfile_register(struct kvm_memory_slot *slot) > > { > > + slot->notifier.ops = &kvm_memfile_notifier_ops; > > return memfile_register_notifier(file_inode(slot->private_file), > > &slot->notifier, > > &slot->pfn_ops); > > @@ -1963,6 +1998,7 @@ int __kvm_set_memory_region(struct kvm *kvm, > > new->private_file = file; > > new->private_offset = mem->flags & KVM_MEM_PRIVATE ? > > region_ext->private_offset : 0; > > + new->kvm = kvm; > > > > r = kvm_set_memslot(kvm, old, new, change); > > if (!r) > > -- > > 2.17.1 > >
WARNING: multiple messages have this Message-ID (diff)
From: Chao Peng <chao.p.peng@linux.intel.com> To: Sean Christopherson <seanjc@google.com> Cc: Wanpeng Li <wanpengli@tencent.com>, jun.nakajima@intel.com, kvm@vger.kernel.org, david@redhat.com, qemu-devel@nongnu.org, "J . Bruce Fields" <bfields@fieldses.org>, linux-mm@kvack.org, "H . Peter Anvin" <hpa@zytor.com>, ak@linux.intel.com, Jonathan Corbet <corbet@lwn.net>, Joerg Roedel <joro@8bytes.org>, x86@kernel.org, Hugh Dickins <hughd@google.com>, Steven Price <steven.price@arm.com>, Ingo Molnar <mingo@redhat.com>, "Maciej S . Szmigiero" <mail@maciej.szmigiero.name>, Borislav Petkov <bp@alien8.de>, luto@kernel.org, Thomas Gleixner <tglx@linutronix.de>, Vitaly Kuznetsov <vkuznets@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Jim Mattson <jmattson@google.com>, dave.hansen@intel.com, linux-api@vger.kernel.org, Jeff Layton <jlayton@kernel.org>, linux-kernel@vger.kernel.org, Yu Zhang <yu.c.zhang@linux.intel.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, linux-fsdevel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Vishal Annapurve <vannapurve@google.com>, Mike Rapoport <rppt@kernel.org> Subject: Re: [PATCH v5 11/13] KVM: Zap existing KVM mappings when pages changed in the private fd Date: Tue, 12 Apr 2022 20:43:25 +0800 [thread overview] Message-ID: <20220412124325.GB8013@chaop.bj.intel.com> (raw) In-Reply-To: <YkNcmGsOw4MThaym@google.com> On Tue, Mar 29, 2022 at 07:23:04PM +0000, Sean Christopherson wrote: > On Thu, Mar 10, 2022, Chao Peng wrote: > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > > index 67349421eae3..52319f49d58a 100644 > > --- a/virt/kvm/kvm_main.c > > +++ b/virt/kvm/kvm_main.c > > @@ -841,8 +841,43 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) > > #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ > > > > #ifdef CONFIG_MEMFILE_NOTIFIER > > +static void kvm_memfile_notifier_handler(struct memfile_notifier *notifier, > > + pgoff_t start, pgoff_t end) > > +{ > > + int idx; > > + struct kvm_memory_slot *slot = container_of(notifier, > > + struct kvm_memory_slot, > > + notifier); > > + struct kvm_gfn_range gfn_range = { > > + .slot = slot, > > + .start = start - (slot->private_offset >> PAGE_SHIFT), > > + .end = end - (slot->private_offset >> PAGE_SHIFT), > > + .may_block = true, > > + }; > > + struct kvm *kvm = slot->kvm; > > + > > + gfn_range.start = max(gfn_range.start, slot->base_gfn); > > + gfn_range.end = min(gfn_range.end, slot->base_gfn + slot->npages); > > + > > + if (gfn_range.start >= gfn_range.end) > > + return; > > + > > + idx = srcu_read_lock(&kvm->srcu); > > + KVM_MMU_LOCK(kvm); > > + kvm_unmap_gfn_range(kvm, &gfn_range); > > + kvm_flush_remote_tlbs(kvm); > > This should check the result of kvm_unmap_gfn_range() and flush only if necessary. Yep. > > kvm->mmu_notifier_seq needs to be incremented, otherwise KVM will incorrectly > install a SPTE if the mapping is zapped between retrieving the pfn in faultin and > installing it after acquire mmu_lock. Good catch. Chao > > > > + KVM_MMU_UNLOCK(kvm); > > + srcu_read_unlock(&kvm->srcu, idx); > > +} > > + > > +static struct memfile_notifier_ops kvm_memfile_notifier_ops = { > > + .invalidate = kvm_memfile_notifier_handler, > > + .fallocate = kvm_memfile_notifier_handler, > > +}; > > + > > static inline int kvm_memfile_register(struct kvm_memory_slot *slot) > > { > > + slot->notifier.ops = &kvm_memfile_notifier_ops; > > return memfile_register_notifier(file_inode(slot->private_file), > > &slot->notifier, > > &slot->pfn_ops); > > @@ -1963,6 +1998,7 @@ int __kvm_set_memory_region(struct kvm *kvm, > > new->private_file = file; > > new->private_offset = mem->flags & KVM_MEM_PRIVATE ? > > region_ext->private_offset : 0; > > + new->kvm = kvm; > > > > r = kvm_set_memslot(kvm, old, new, change); > > if (!r) > > -- > > 2.17.1 > >
next prev parent reply other threads:[~2022-04-12 13:07 UTC|newest] Thread overview: 183+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-10 14:08 [PATCH v5 00/13] KVM: mm: fd-based approach for supporting KVM guest private memory Chao Peng 2022-03-10 14:08 ` Chao Peng 2022-03-10 14:08 ` [PATCH v5 01/13] mm/memfd: Introduce MFD_INACCESSIBLE flag Chao Peng 2022-03-10 14:08 ` Chao Peng 2022-04-11 15:10 ` Kirill A. Shutemov 2022-04-11 15:10 ` Kirill A. Shutemov 2022-04-12 13:11 ` Chao Peng 2022-04-12 13:11 ` Chao Peng 2022-04-23 5:43 ` Vishal Annapurve 2022-04-24 8:15 ` Chao Peng 2022-04-24 8:15 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 02/13] mm: Introduce memfile_notifier Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 18:45 ` Sean Christopherson 2022-04-08 12:54 ` Chao Peng 2022-04-08 12:54 ` Chao Peng 2022-04-12 14:36 ` Hillf Danton 2022-04-13 6:47 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 03/13] mm/shmem: Support memfile_notifier Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-10 23:08 ` Dave Chinner 2022-03-10 23:08 ` Dave Chinner 2022-03-11 8:42 ` Chao Peng 2022-03-11 8:42 ` Chao Peng 2022-04-11 15:26 ` Kirill A. Shutemov 2022-04-11 15:26 ` Kirill A. Shutemov 2022-04-12 13:12 ` Chao Peng 2022-04-12 13:12 ` Chao Peng 2022-04-19 22:40 ` Vishal Annapurve 2022-04-20 3:24 ` Chao Peng 2022-04-20 3:24 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 04/13] mm/shmem: Restrict MFD_INACCESSIBLE memory against RLIMIT_MEMLOCK Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-04-07 16:05 ` Sean Christopherson 2022-04-07 17:09 ` Andy Lutomirski 2022-04-07 17:09 ` Andy Lutomirski 2022-04-08 17:56 ` Sean Christopherson 2022-04-08 18:54 ` David Hildenbrand 2022-04-08 18:54 ` David Hildenbrand 2022-04-12 14:36 ` Jason Gunthorpe 2022-04-12 14:36 ` Jason Gunthorpe 2022-04-12 21:27 ` Andy Lutomirski 2022-04-12 21:27 ` Andy Lutomirski 2022-04-13 16:30 ` David Hildenbrand 2022-04-13 16:30 ` David Hildenbrand 2022-04-13 16:24 ` David Hildenbrand 2022-04-13 16:24 ` David Hildenbrand 2022-04-13 17:52 ` Jason Gunthorpe 2022-04-13 17:52 ` Jason Gunthorpe 2022-04-25 14:07 ` David Hildenbrand 2022-04-25 14:07 ` David Hildenbrand 2022-04-08 13:02 ` Chao Peng 2022-04-08 13:02 ` Chao Peng 2022-04-11 15:34 ` Kirill A. Shutemov 2022-04-11 15:34 ` Kirill A. Shutemov 2022-04-12 5:14 ` Hugh Dickins 2022-04-11 15:32 ` Kirill A. Shutemov 2022-04-11 15:32 ` Kirill A. Shutemov 2022-04-12 13:39 ` Chao Peng 2022-04-12 13:39 ` Chao Peng 2022-04-12 19:28 ` Kirill A. Shutemov 2022-04-12 19:28 ` Kirill A. Shutemov 2022-04-13 9:15 ` Chao Peng 2022-04-13 9:15 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 05/13] KVM: Extend the memslot to support fd-based private memory Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 21:27 ` Sean Christopherson 2022-04-08 13:21 ` Chao Peng 2022-04-08 13:21 ` Chao Peng 2022-03-28 21:56 ` Sean Christopherson 2022-04-08 13:46 ` Chao Peng 2022-04-08 13:46 ` Chao Peng 2022-04-08 17:45 ` Sean Christopherson 2022-03-10 14:09 ` [PATCH v5 06/13] KVM: Use kvm_userspace_memory_region_ext Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 22:26 ` Sean Christopherson 2022-04-08 13:58 ` Chao Peng 2022-04-08 13:58 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 07/13] KVM: Add KVM_EXIT_MEMORY_ERROR exit Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 22:33 ` Sean Christopherson 2022-04-08 13:59 ` Chao Peng 2022-04-08 13:59 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 08/13] KVM: Use memfile_pfn_ops to obtain pfn for private pages Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-28 23:56 ` Sean Christopherson 2022-04-08 14:07 ` Chao Peng 2022-04-08 14:07 ` Chao Peng 2022-04-28 12:37 ` Chao Peng 2022-04-28 12:37 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 09/13] KVM: Handle page fault for private memory Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 1:07 ` Sean Christopherson 2022-04-12 12:10 ` Chao Peng 2022-04-12 12:10 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 10/13] KVM: Register private memslot to memory backing store Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 19:01 ` Sean Christopherson 2022-04-12 12:40 ` Chao Peng 2022-04-12 12:40 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 11/13] KVM: Zap existing KVM mappings when pages changed in the private fd Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 19:23 ` Sean Christopherson 2022-04-12 12:43 ` Chao Peng [this message] 2022-04-12 12:43 ` Chao Peng 2022-04-05 23:45 ` Michael Roth 2022-04-08 3:06 ` Sean Christopherson 2022-04-19 22:43 ` Vishal Annapurve 2022-04-20 3:17 ` Chao Peng 2022-04-20 3:17 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 12/13] KVM: Expose KVM_MEM_PRIVATE Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-29 19:13 ` Sean Christopherson 2022-04-12 12:56 ` Chao Peng 2022-04-12 12:56 ` Chao Peng 2022-03-10 14:09 ` [PATCH v5 13/13] memfd_create.2: Describe MFD_INACCESSIBLE flag Chao Peng 2022-03-10 14:09 ` Chao Peng 2022-03-24 15:51 ` [PATCH v5 00/13] KVM: mm: fd-based approach for supporting KVM guest private memory Quentin Perret 2022-03-28 17:13 ` Sean Christopherson 2022-03-28 18:00 ` Quentin Perret 2022-03-28 18:58 ` Sean Christopherson 2022-03-29 17:01 ` Quentin Perret 2022-03-30 8:58 ` Steven Price 2022-03-30 8:58 ` Steven Price 2022-03-30 10:39 ` Quentin Perret 2022-03-30 17:58 ` Sean Christopherson 2022-03-31 16:04 ` Andy Lutomirski 2022-03-31 16:04 ` Andy Lutomirski 2022-04-01 14:59 ` Quentin Perret 2022-04-01 17:14 ` Sean Christopherson 2022-04-01 18:03 ` Quentin Perret 2022-04-01 18:24 ` Sean Christopherson 2022-04-01 19:56 ` Andy Lutomirski 2022-04-01 19:56 ` Andy Lutomirski 2022-04-04 15:01 ` Quentin Perret 2022-04-04 17:06 ` Sean Christopherson 2022-04-04 22:04 ` Andy Lutomirski 2022-04-04 22:04 ` Andy Lutomirski 2022-04-05 10:36 ` Quentin Perret 2022-04-05 17:51 ` Andy Lutomirski 2022-04-05 17:51 ` Andy Lutomirski 2022-04-05 18:30 ` Sean Christopherson 2022-04-06 18:42 ` Andy Lutomirski 2022-04-06 18:42 ` Andy Lutomirski 2022-04-06 13:05 ` Quentin Perret 2022-04-05 18:03 ` Sean Christopherson 2022-04-06 10:34 ` Quentin Perret 2022-04-22 10:56 ` Chao Peng 2022-04-22 10:56 ` Chao Peng 2022-04-22 11:06 ` Paolo Bonzini 2022-04-22 11:06 ` Paolo Bonzini 2022-04-24 8:07 ` Chao Peng 2022-04-24 8:07 ` Chao Peng 2022-04-24 16:59 ` Andy Lutomirski 2022-04-24 16:59 ` Andy Lutomirski 2022-04-25 13:40 ` Chao Peng 2022-04-25 13:40 ` Chao Peng 2022-04-25 14:52 ` Andy Lutomirski 2022-04-25 14:52 ` Andy Lutomirski 2022-04-25 20:30 ` Sean Christopherson 2022-06-10 19:18 ` Andy Lutomirski 2022-06-10 19:27 ` Sean Christopherson 2022-04-28 12:29 ` Chao Peng 2022-04-28 12:29 ` Chao Peng 2022-05-03 11:12 ` Quentin Perret 2022-05-09 22:30 ` Michael Roth 2022-05-09 23:29 ` Sean Christopherson 2022-07-21 20:05 ` Gupta, Pankaj 2022-07-21 21:19 ` Sean Christopherson 2022-07-21 21:36 ` Gupta, Pankaj 2022-07-23 3:09 ` Andy Lutomirski 2022-07-25 9:19 ` Gupta, Pankaj 2022-03-30 16:18 ` Sean Christopherson 2022-03-28 20:16 ` Andy Lutomirski 2022-03-28 20:16 ` Andy Lutomirski 2022-03-28 22:48 ` Nakajima, Jun 2022-03-28 22:48 ` Nakajima, Jun 2022-03-29 0:04 ` Sean Christopherson 2022-04-08 21:35 ` Vishal Annapurve 2022-04-12 13:00 ` Chao Peng 2022-04-12 13:00 ` Chao Peng 2022-04-12 19:58 ` Kirill A. Shutemov 2022-04-12 19:58 ` Kirill A. Shutemov
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