From patchwork Tue Jun 6 19:03:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ackerley Tng X-Patchwork-Id: 13269587 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 D06E5C77B7A for ; Tue, 6 Jun 2023 19:06:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239399AbjFFTGE (ORCPT ); Tue, 6 Jun 2023 15:06:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239398AbjFFTFA (ORCPT ); Tue, 6 Jun 2023 15:05:00 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 485C01BD2 for ; Tue, 6 Jun 2023 12:04:38 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id 98e67ed59e1d1-25669acf204so5848050a91.2 for ; Tue, 06 Jun 2023 12:04:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1686078277; x=1688670277; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=l7m/+H3bbKiFYeplsxMS6SzLQH+bOrcqP3X6Nh5dkpY=; b=14V+ikDqPeP4Yv1OdmN8nd7QZ5MMjeGKWKaRSYFOZag9l1JWEXWB4ucnpLMnABlXZA EKyjA/Hep4b5XPLE3jo+/oAtPajUrqdw+KeK/h9os1d0usuctIgWW9M+esmzYCfBXl4x ASFKNceH4Dvr96zHhOZ0uM2fLtsPSrNxdz17wPPKIRFX8xmJyoeEp2adnxvZEKqN8X4Y OM4Rksx4vK290PDLeLyuR9aPGnO/Zd4sMVHFMKGC9zk+GBNtZUBayI8BLZ7Yas0LD8pw GLTAE9YptousowvGxGw0V5tbYjLuLpB0CEXyROZYUG+NBDy7fuPXlo1tE0nXFLN+WEBW wc/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686078277; x=1688670277; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=l7m/+H3bbKiFYeplsxMS6SzLQH+bOrcqP3X6Nh5dkpY=; b=mAI82/0EHYxQlSY1318L7Y/etLfeyJi7ZMLHGm5JAWn6zf6d/iVfjccHVAuUjgS5bR caeDlAS9aAqmbEU9eJTgpVdcMUocPDUlMa9/yZpPzCz/k+CzGjluoQJGxDgddbg+9K/8 08z+sAtFo5BXlZn15G/3pKDYhLpNEU1BtLsHaSCniZRhKZLAtcQ3vM5bph5FbjQRWDp6 8Q4lcAKQaD1JeUD7sjXED7lOFKkN8oDjSgiYQuOAryj/GVMkJIHYHHq94sfWGvu4ECJP Hqm14Y1vzk9vtggIfICNyf4bBSn23/W+GB8Q/XUAHtsZUaTU2Vh1Y9w+hv3E3fCKZQ3y AyzA== X-Gm-Message-State: AC+VfDynN0eQlTrRFSIkDJoRCRvYk8RLpdTspz9ymqtZGQRbaz2+9X8O 6QtsyDMzTmGLzS5E9WMaLs40Yrt/pafNp5urRw== X-Google-Smtp-Source: ACHHUZ400PPpzSqOQyBrlXwnbK9H57gIHhF9scqTSjoAqyx8OcXSiJ7wdR2icZ3OG98VTDSuHd/HQ93iA5Sxt1cqNg== X-Received: from ackerleytng-ctop.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:13f8]) (user=ackerleytng job=sendgmr) by 2002:a17:90b:3003:b0:253:4808:7587 with SMTP id hg3-20020a17090b300300b0025348087587mr772798pjb.7.1686078277257; Tue, 06 Jun 2023 12:04:37 -0700 (PDT) Date: Tue, 6 Jun 2023 19:03:58 +0000 In-Reply-To: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <67168b07e8d4a0c714fce5f030671b376d8ca001.1686077275.git.ackerleytng@google.com> Subject: [RFC PATCH 13/19] KVM: guest_mem: Refactor kvm_gmem fd creation to be in layers From: Ackerley Tng To: akpm@linux-foundation.org, mike.kravetz@oracle.com, muchun.song@linux.dev, pbonzini@redhat.com, seanjc@google.com, shuah@kernel.org, willy@infradead.org Cc: brauner@kernel.org, chao.p.peng@linux.intel.com, coltonlewis@google.com, david@redhat.com, dhildenb@redhat.com, dmatlack@google.com, erdemaktas@google.com, hughd@google.com, isaku.yamahata@gmail.com, jarkko@kernel.org, jmattson@google.com, joro@8bytes.org, jthoughton@google.com, jun.nakajima@intel.com, kirill.shutemov@linux.intel.com, liam.merwick@oracle.com, mail@maciej.szmigiero.name, mhocko@suse.com, michael.roth@amd.com, qperret@google.com, rientjes@google.com, rppt@kernel.org, steven.price@arm.com, tabba@google.com, vannapurve@google.com, vbabka@suse.cz, vipinsh@google.com, vkuznets@redhat.com, wei.w.wang@intel.com, yu.c.zhang@linux.intel.com, kvm@vger.kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, qemu-devel@nongnu.org, x86@kernel.org, Ackerley Tng Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org First create a gmem inode, then create a gmem file using the inode, then install the file into an fd. Creating the file in layers separates inode concepts (struct kvm_gmem) from file concepts and makes cleaning up in stages neater. Signed-off-by: Ackerley Tng --- virt/kvm/guest_mem.c | 86 +++++++++++++++++++++++++------------------- 1 file changed, 50 insertions(+), 36 deletions(-) diff --git a/virt/kvm/guest_mem.c b/virt/kvm/guest_mem.c index 8708139822d3..2f69ef666871 100644 --- a/virt/kvm/guest_mem.c +++ b/virt/kvm/guest_mem.c @@ -375,41 +375,27 @@ static const struct inode_operations kvm_gmem_iops = { .setattr = kvm_gmem_setattr, }; -static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags, - struct vfsmount *mnt) +static struct inode *kvm_gmem_create_inode(struct kvm *kvm, loff_t size, u64 flags, + struct vfsmount *mnt) { + int err; + struct inode *inode; + struct kvm_gmem *gmem; const char *anon_name = "[kvm-gmem]"; const struct qstr qname = QSTR_INIT(anon_name, strlen(anon_name)); - struct kvm_gmem *gmem; - struct inode *inode; - struct file *file; - int fd, err; - - fd = get_unused_fd_flags(0); - if (fd < 0) - return fd; inode = alloc_anon_inode(mnt->mnt_sb); - if (IS_ERR(inode)) { - err = PTR_ERR(inode); - goto err_fd; - } + if (IS_ERR(inode)) + return inode; err = security_inode_init_security_anon(inode, &qname, NULL); if (err) goto err_inode; - file = alloc_file_pseudo(inode, mnt, "kvm-gmem", O_RDWR, &kvm_gmem_fops); - if (IS_ERR(file)) { - err = PTR_ERR(file); - goto err_inode; - } - + err = -ENOMEM; gmem = kzalloc(sizeof(*gmem), GFP_KERNEL); - if (!gmem) { - err = -ENOMEM; - goto err_file; - } + if (!gmem) + goto err_inode; xa_init(&gmem->bindings); @@ -426,24 +412,41 @@ static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags, mapping_set_large_folios(inode->i_mapping); mapping_set_unevictable(inode->i_mapping); - file->f_flags |= O_LARGEFILE; - file->f_mapping = inode->i_mapping; - file->private_data = gmem; - - fd_install(fd, file); - return fd; + return inode; -err_file: - fput(file); err_inode: iput(inode); -err_fd: - put_unused_fd(fd); - return err; + return ERR_PTR(err); +} + + +static struct file *kvm_gmem_create_file(struct kvm *kvm, loff_t size, u64 flags, + struct vfsmount *mnt) +{ + struct file *file; + struct inode *inode; + + inode = kvm_gmem_create_inode(kvm, size, flags, mnt); + if (IS_ERR(inode)) + return ERR_CAST(inode); + + file = alloc_file_pseudo(inode, mnt, "kvm-gmem", O_RDWR, &kvm_gmem_fops); + if (IS_ERR(file)) { + iput(inode); + return file; + } + + file->f_flags |= O_LARGEFILE; + file->f_mapping = inode->i_mapping; + file->private_data = inode->i_mapping->private_data; + + return file; } int kvm_gmem_create(struct kvm *kvm, struct kvm_create_guest_memfd *gmem) { + int fd; + struct file *file; loff_t size = gmem->size; u64 flags = gmem->flags; @@ -462,7 +465,18 @@ int kvm_gmem_create(struct kvm *kvm, struct kvm_create_guest_memfd *gmem) #endif } - return __kvm_gmem_create(kvm, size, flags, kvm_gmem_mnt); + fd = get_unused_fd_flags(0); + if (fd < 0) + return fd; + + file = kvm_gmem_create_file(kvm, size, flags, kvm_gmem_mnt); + if (IS_ERR(file)) { + put_unused_fd(fd); + return PTR_ERR(file); + } + + fd_install(fd, file); + return fd; } int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot *slot,