From patchwork Tue Jan 18 13:21:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Peng X-Patchwork-Id: 12716364 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 32318C433EF for ; Tue, 18 Jan 2022 13:23:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B7C1B6B0072; Tue, 18 Jan 2022 08:23:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B2B3D6B0089; Tue, 18 Jan 2022 08:23:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9F34F6B008C; Tue, 18 Jan 2022 08:23:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0249.hostedemail.com [216.40.44.249]) by kanga.kvack.org (Postfix) with ESMTP id 917AD6B0072 for ; Tue, 18 Jan 2022 08:23:14 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 52CAB824C420 for ; Tue, 18 Jan 2022 13:23:14 +0000 (UTC) X-FDA: 79043473908.04.3C654AC Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf01.hostedemail.com (Postfix) with ESMTP id 132E940004 for ; Tue, 18 Jan 2022 13:23:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1642512193; x=1674048193; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=EeAqQ9F4s9hLs6erZUPGg6L9PNHtGyg9c724TwmrBc4=; b=nOiuPnzq1d5fvpRg4hfVeI111nPtAA6o6d+OM6CkSxgo2aJ5B2vrlbsX 53lWWkcsjkKKJ7hpEffL375BVpS2GHH28nCchSqIel8xMbRJBbj0Gu+ZM Vo2N9XnfMHTyJOYMeBTyX2T1+tU1JNPYdodnyYbla+GOaCfhE9Tp3/UhN iK4hWvXYWjCAfoK0o0/wK7Vmxe9k/LR47XJEnkY8mzmkt/df969lqr68T jjWCLX8VdFWeKG+bzoYEiky46hEMcwEqHyhsvBOIJKiwnYZL4Y2iT4MsD AYUiag3MP6SJTmftTy8rvhIPftHG+FZyQwOOBnPYgjusec7QpCD9C5bWP w==; X-IronPort-AV: E=McAfee;i="6200,9189,10230"; a="245007992" X-IronPort-AV: E=Sophos;i="5.88,297,1635231600"; d="scan'208";a="245007992" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jan 2022 05:23:11 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,297,1635231600"; d="scan'208";a="531791917" Received: from chaop.bj.intel.com ([10.240.192.101]) by orsmga008.jf.intel.com with ESMTP; 18 Jan 2022 05:23:04 -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, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: [PATCH v4 10/12] KVM: Register private memslot to memory backing store Date: Tue, 18 Jan 2022 21:21:19 +0800 Message-Id: <20220118132121.31388-11-chao.p.peng@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220118132121.31388-1-chao.p.peng@linux.intel.com> References: <20220118132121.31388-1-chao.p.peng@linux.intel.com> X-Rspamd-Queue-Id: 132E940004 X-Stat-Signature: caxe3jgcnj7z85bwequ16pqzkfo83kz3 Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=nOiuPnzq; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf01.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=chao.p.peng@linux.intel.com X-Rspamd-Server: rspam02 X-HE-Tag: 1642512192-358583 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: Add 'notifier' to memslot to make it a memfile_notifier node and then register it to memory backing store via memfile_register_notifier() when memslot gets created. When memslot is deleted, do the reverse with memfile_unregister_notifier(). Note each KVM memslot can be registered to different memory backing stores (or the same backing store but at different offset) independently. Signed-off-by: Yu Zhang Signed-off-by: Chao Peng --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 75 ++++++++++++++++++++++++++++++++++++---- 2 files changed, 70 insertions(+), 6 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 927e7f44a02a..667efe839767 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -462,6 +462,7 @@ struct kvm_memory_slot { struct file *private_file; loff_t private_offset; struct memfile_pfn_ops *pfn_ops; + struct memfile_notifier notifier; }; static inline bool kvm_slot_is_private(const struct kvm_memory_slot *slot) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ecf94e2548f7..6b78ddef7880 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -846,6 +846,37 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +#ifdef CONFIG_MEMFILE_NOTIFIER +static inline int kvm_memfile_register(struct kvm_memory_slot *slot) +{ + return memfile_register_notifier(file_inode(slot->private_file), + &slot->notifier, + &slot->pfn_ops); +} + +static inline void kvm_memfile_unregister(struct kvm_memory_slot *slot) +{ + if (slot->private_file) { + memfile_unregister_notifier(file_inode(slot->private_file), + &slot->notifier); + fput(slot->private_file); + slot->private_file = NULL; + } +} + +#else /* !CONFIG_MEMFILE_NOTIFIER */ + +static inline int kvm_memfile_register(struct kvm_memory_slot *slot) +{ + return -EOPNOTSUPP; +} + +static inline void kvm_memfile_unregister(struct kvm_memory_slot *slot) +{ +} + +#endif /* CONFIG_MEMFILE_NOTIFIER */ + #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER static int kvm_pm_notifier_call(struct notifier_block *bl, unsigned long state, @@ -890,6 +921,9 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_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_memfile_unregister(slot); + kvm_destroy_dirty_bitmap(slot); kvm_arch_free_memslot(kvm, slot); @@ -1744,6 +1778,12 @@ static int kvm_set_memslot(struct kvm *kvm, kvm_invalidate_memslot(kvm, old, invalid_slot); } + if (new->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) { + r = kvm_memfile_register(new); + if (r) + return r; + } + r = kvm_prepare_memory_region(kvm, old, new, change); if (r) { /* @@ -1758,6 +1798,10 @@ static int kvm_set_memslot(struct kvm *kvm, } else { mutex_unlock(&kvm->slots_arch_lock); } + + if (new->flags & KVM_MEM_PRIVATE && change == KVM_MR_CREATE) + kvm_memfile_unregister(new); + return r; } @@ -1823,6 +1867,7 @@ int __kvm_set_memory_region(struct kvm *kvm, enum kvm_mr_change change; unsigned long npages; gfn_t base_gfn; + struct file *file = NULL; int as_id, id; int r; @@ -1896,14 +1941,24 @@ int __kvm_set_memory_region(struct kvm *kvm, return 0; } + if (mem->flags & KVM_MEM_PRIVATE) { + file = fdget(region_ext->private_fd).file; + if (!file) + return -EINVAL; + } + if ((change == KVM_MR_CREATE || change == KVM_MR_MOVE) && - kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages)) - return -EEXIST; + kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages)) { + r = -EEXIST; + goto out; + } /* Allocate a slot that will persist in the memslot. */ new = kzalloc(sizeof(*new), GFP_KERNEL_ACCOUNT); - if (!new) - return -ENOMEM; + if (!new) { + r = -ENOMEM; + goto out; + } new->as_id = as_id; new->id = id; @@ -1911,10 +1966,18 @@ int __kvm_set_memory_region(struct kvm *kvm, new->npages = npages; new->flags = mem->flags; new->userspace_addr = mem->userspace_addr; + new->private_file = file; + new->private_offset = mem->flags & KVM_MEM_PRIVATE ? + region_ext->private_offset : 0; r = kvm_set_memslot(kvm, old, new, change); - if (r) - kfree(new); + if (!r) + return r; + + kfree(new); +out: + if (file) + fput(file); return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region);