From: Chao Peng <chao.p.peng@linux.intel.com> To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.org Cc: Paolo Bonzini <pbonzini@redhat.com>, Jonathan Corbet <corbet@lwn.net>, Sean Christopherson <seanjc@google.com>, 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>, Yu Zhang <yu.c.zhang@linux.intel.com>, Chao Peng <chao.p.peng@linux.intel.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, luto@kernel.org, john.ji@intel.com, susie.li@intel.com, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: [PATCH v3 11/15] KVM: Implement fd-based memory fallocation Date: Tue, 21 Dec 2021 23:11:21 +0800 [thread overview] Message-ID: <20211221151125.19446-12-chao.p.peng@linux.intel.com> (raw) In-Reply-To: <20211221151125.19446-1-chao.p.peng@linux.intel.com> KVM gets notified through memfd_notifier when user space allocate space via fallocate() on the fd which is used for guest memory. KVM can set up the mapping in the secondary MMU page tables at this time. This patch adds function in KVM to map pfn to gfn when the page is allocated in the memory backend. While it's possible to postpone the mapping of the secondary MMU to KVM page fault handler but we can reduce some VMExits by also mapping the secondary page tables when a page is mapped in the primary MMU. It reuses the same code for kvm_memfd_invalidate_range, except using kvm_map_gfn_range as its handler. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 22 +++++++++++++++++++--- virt/kvm/memfd.c | 2 ++ 3 files changed, 23 insertions(+), 3 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9c02fb53b8ab..1f69d76983a2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1879,6 +1879,8 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu) #ifdef CONFIG_MEMFD_OPS int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, unsigned long start, unsigned long end); +int kvm_memfd_fallocate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end); #endif /* CONFIG_MEMFD_OPS */ diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b9855b2fdaae..1b7cf05759c7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -860,15 +860,17 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ #ifdef CONFIG_MEMFD_OPS -int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, - unsigned long start, unsigned long end) +int kvm_memfd_handle_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end, + gfn_handler_t handler) + { int ret; const struct kvm_useraddr_range useraddr_range = { .start = start, .end = end, .pte = __pte(0), - .handler = kvm_unmap_gfn_range, + .handler = handler, .on_lock = (void *)kvm_null_fn, .flush_on_ret = true, .may_block = false, @@ -883,6 +885,20 @@ int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, return ret; } + +int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end) +{ + return kvm_memfd_handle_range(kvm, inode, start, end, + kvm_unmap_gfn_range); +} + +int kvm_memfd_fallocate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end) +{ + return kvm_memfd_handle_range(kvm, inode, start, end, + kvm_map_gfn_range); +} #endif /* CONFIG_MEMFD_OPS */ #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER diff --git a/virt/kvm/memfd.c b/virt/kvm/memfd.c index d092a9b6f496..e7a2ab790cc6 100644 --- a/virt/kvm/memfd.c +++ b/virt/kvm/memfd.c @@ -23,6 +23,8 @@ static void memfd_invalidate_page_range(struct inode *inode, void *owner, static void memfd_fallocate(struct inode *inode, void *owner, pgoff_t start, pgoff_t end) { + kvm_memfd_fallocate_range(owner, inode, start >> PAGE_SHIFT, + end >> PAGE_SHIFT); } static bool memfd_get_owner(void *owner) -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Chao Peng <chao.p.peng@linux.intel.com> To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.org Cc: Wanpeng Li <wanpengli@tencent.com>, jun.nakajima@intel.com, david@redhat.com, "J . Bruce Fields" <bfields@fieldses.org>, dave.hansen@intel.com, "H . Peter Anvin" <hpa@zytor.com>, Chao Peng <chao.p.peng@linux.intel.com>, ak@linux.intel.com, Jonathan Corbet <corbet@lwn.net>, Joerg Roedel <joro@8bytes.org>, x86@kernel.org, Hugh Dickins <hughd@google.com>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, luto@kernel.org, Thomas Gleixner <tglx@linutronix.de>, Vitaly Kuznetsov <vkuznets@redhat.com>, Jim Mattson <jmattson@google.com>, Sean Christopherson <seanjc@google.com>, susie.li@intel.com, Jeff Layton <jlayton@kernel.org>, john.ji@intel.com, Yu Zhang <yu.c.zhang@linux.intel.com>, Paolo Bonzini <pbonzini@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Subject: [PATCH v3 11/15] KVM: Implement fd-based memory fallocation Date: Tue, 21 Dec 2021 23:11:21 +0800 [thread overview] Message-ID: <20211221151125.19446-12-chao.p.peng@linux.intel.com> (raw) In-Reply-To: <20211221151125.19446-1-chao.p.peng@linux.intel.com> KVM gets notified through memfd_notifier when user space allocate space via fallocate() on the fd which is used for guest memory. KVM can set up the mapping in the secondary MMU page tables at this time. This patch adds function in KVM to map pfn to gfn when the page is allocated in the memory backend. While it's possible to postpone the mapping of the secondary MMU to KVM page fault handler but we can reduce some VMExits by also mapping the secondary page tables when a page is mapped in the primary MMU. It reuses the same code for kvm_memfd_invalidate_range, except using kvm_map_gfn_range as its handler. Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 22 +++++++++++++++++++--- virt/kvm/memfd.c | 2 ++ 3 files changed, 23 insertions(+), 3 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9c02fb53b8ab..1f69d76983a2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1879,6 +1879,8 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu) #ifdef CONFIG_MEMFD_OPS int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, unsigned long start, unsigned long end); +int kvm_memfd_fallocate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end); #endif /* CONFIG_MEMFD_OPS */ diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b9855b2fdaae..1b7cf05759c7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -860,15 +860,17 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ #ifdef CONFIG_MEMFD_OPS -int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, - unsigned long start, unsigned long end) +int kvm_memfd_handle_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end, + gfn_handler_t handler) + { int ret; const struct kvm_useraddr_range useraddr_range = { .start = start, .end = end, .pte = __pte(0), - .handler = kvm_unmap_gfn_range, + .handler = handler, .on_lock = (void *)kvm_null_fn, .flush_on_ret = true, .may_block = false, @@ -883,6 +885,20 @@ int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, return ret; } + +int kvm_memfd_invalidate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end) +{ + return kvm_memfd_handle_range(kvm, inode, start, end, + kvm_unmap_gfn_range); +} + +int kvm_memfd_fallocate_range(struct kvm *kvm, struct inode *inode, + unsigned long start, unsigned long end) +{ + return kvm_memfd_handle_range(kvm, inode, start, end, + kvm_map_gfn_range); +} #endif /* CONFIG_MEMFD_OPS */ #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER diff --git a/virt/kvm/memfd.c b/virt/kvm/memfd.c index d092a9b6f496..e7a2ab790cc6 100644 --- a/virt/kvm/memfd.c +++ b/virt/kvm/memfd.c @@ -23,6 +23,8 @@ static void memfd_invalidate_page_range(struct inode *inode, void *owner, static void memfd_fallocate(struct inode *inode, void *owner, pgoff_t start, pgoff_t end) { + kvm_memfd_fallocate_range(owner, inode, start >> PAGE_SHIFT, + end >> PAGE_SHIFT); } static bool memfd_get_owner(void *owner) -- 2.17.1
next prev parent reply other threads:[~2021-12-21 15:13 UTC|newest] Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-21 15:11 [PATCH v3 00/15] KVM: mm: fd-based approach for supporting KVM guest private memory Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 01/15] mm/shmem: Introduce F_SEAL_INACCESSIBLE Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 02/15] mm/memfd: Introduce MFD_INACCESSIBLE flag Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 03/15] mm/memfd: Introduce MEMFD_OPS Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 04/15] KVM: Extend the memslot to support fd-based private memory Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 05/15] KVM: Implement fd-based memory using MEMFD_OPS interfaces Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 06/15] KVM: Refactor hva based memory invalidation code Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 07/15] KVM: Special handling for fd-based memory invalidation Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 08/15] KVM: Split out common memory invalidation code Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 09/15] KVM: Implement fd-based memory invalidation Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 10/15] KVM: Add kvm_map_gfn_range Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` Chao Peng [this message] 2021-12-21 15:11 ` [PATCH v3 11/15] KVM: Implement fd-based memory fallocation Chao Peng 2021-12-21 15:11 ` [PATCH v3 12/15] KVM: Add KVM_EXIT_MEMORY_ERROR exit Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 13/15] KVM: Handle page fault for private memory Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 14/15] KVM: Use kvm_userspace_memory_region_ext Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:11 ` [PATCH v3 15/15] KVM: Register/unregister private memory slot to memfd Chao Peng 2021-12-21 15:11 ` Chao Peng 2021-12-21 15:44 ` [PATCH v3 00/15] KVM: mm: fd-based approach for supporting KVM guest private memory Sean Christopherson 2021-12-22 1:22 ` Chao Peng 2021-12-22 1:22 ` Chao Peng
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