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: 12689883 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D25BC433F5 for ; Tue, 21 Dec 2021 15:13:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 083866B009A; Tue, 21 Dec 2021 10:13:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 00B616B009B; Tue, 21 Dec 2021 10:13:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D783C6B009C; Tue, 21 Dec 2021 10:13:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0127.hostedemail.com [216.40.44.127]) by kanga.kvack.org (Postfix) with ESMTP id AD5A16B009A for ; Tue, 21 Dec 2021 10:13:42 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 6F7BA768DB for ; Tue, 21 Dec 2021 15:13:42 +0000 (UTC) X-FDA: 78942145884.11.9E26E0F Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by imf19.hostedemail.com (Postfix) with ESMTP id BD1941A000E for ; Tue, 21 Dec 2021 15:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1640099621; x=1671635621; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=lwc3ZTobl3LT/VFyxod/1mSSsZKwyN5jd9bV9BUSQp0=; b=WvhgfHjCK2+beDSZxJJIlwLv8lj9W6G/ygfrq/LJ0DmfpWHb84CvKURN egdSHb+kQT+BB/DohV2oE5ROcFgF47Arra3uL0tcblunVOtVpgCLRxVR3 xhfzH0k7eadrHdN3Mha9WqeNGuFLgvrcvg/gMHEY3SbG21fp03JoY22KS TzxYgv6KGhyElydQN0ik7afLSLSz/9F/eO8Lz3ROzqEASa3jO8THhzJ6d LuPHUPbrRSkT+XFPL73RGk2Dzon82DmCUyab8jbK0xWTb+kJn5s4Hn+9S eCNjvlpeuKIG0tzxd1gvWTqo69QB2lpXYOZMtX0SChDXG8CUxeWwhDLwu w==; X-IronPort-AV: E=McAfee;i="6200,9189,10204"; a="240364277" X-IronPort-AV: E=Sophos;i="5.88,223,1635231600"; d="scan'208";a="240364277" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.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> X-Rspamd-Queue-Id: BD1941A000E X-Stat-Signature: uohc8ntixnzc496uyt8hjc73gqbwmj5t Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=WvhgfHjC; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf19.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 134.134.136.65) smtp.mailfrom=chao.p.peng@linux.intel.com X-Rspamd-Server: rspam11 X-HE-Tag: 1640099621-945287 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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)