From patchwork Tue Dec 21 15:11:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Peng X-Patchwork-Id: 12689919 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94C10C4332F for ; Tue, 21 Dec 2021 15:13:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239180AbhLUPNp (ORCPT ); Tue, 21 Dec 2021 10:13:45 -0500 Received: from mga09.intel.com ([134.134.136.24]:56009 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232682AbhLUPNo (ORCPT ); Tue, 21 Dec 2021 10:13:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1640099624; x=1671635624; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=lwc3ZTobl3LT/VFyxod/1mSSsZKwyN5jd9bV9BUSQp0=; b=c5kUBbntEVG2G41z2dZrWzIvKoaYPYFrq2nvo4urtbTj8dojlNOs1s9y fQVUnB+oAUSuXRwEbI+FD8XPgagldCVG2ySkjnk9Pgf1uBvpWI6h+ZY3v PuikC/s1QCkXarP+vP/Hs6pwPM5uM+h7kh9TrKjYmWALeRUwpuj8uFWeT PXoMx40akGRri7YSrWiVZR/q3wq7AAlB++1vY57UO5m/1KXtVd4I4YZDL zGev8s0P031w2jczOV/Z6qZzdI7PejFqkMcj8i9uYl+hpvxKOTt2hofsC urKw1Stu3KBcrBNmMLf1t9jzRjfE1IvmQlFB2lpoENo7H8E9wxEsn6Okr g==; X-IronPort-AV: E=McAfee;i="6200,9189,10204"; a="240216715" X-IronPort-AV: E=Sophos;i="5.88,223,1635231600"; d="scan'208";a="240216715" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2021 07:13:33 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,223,1635231600"; d="scan'208";a="684688572" Received: from chaop.bj.intel.com ([10.240.192.101]) by orsmga005.jf.intel.com with ESMTP; 21 Dec 2021 07:13:26 -0800 From: Chao Peng 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 , Jonathan Corbet , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Yu Zhang , Chao Peng , "Kirill A . Shutemov" , 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 Message-Id: <20211221151125.19446-12-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211221151125.19446-1-chao.p.peng@linux.intel.com> References: <20211221151125.19446-1-chao.p.peng@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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 Signed-off-by: Chao Peng --- 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)