From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B4534C77B72 for ; Sat, 15 Apr 2023 00:07:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pnTQq-0000nR-4g; Fri, 14 Apr 2023 20:06:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from <3b-o5ZAYKClQE0w95y2AA270.yA8C08G-z0H079A929G.AD2@flex--seanjc.bounces.google.com>) id 1pnTQk-0000n6-J0 for qemu-devel@nongnu.org; Fri, 14 Apr 2023 20:06:14 -0400 Received: from mail-pg1-x54a.google.com ([2607:f8b0:4864:20::54a]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from <3b-o5ZAYKClQE0w95y2AA270.yA8C08G-z0H079A929G.AD2@flex--seanjc.bounces.google.com>) id 1pnTQh-00081Y-JS for qemu-devel@nongnu.org; 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bh=27SavXWsOz2fFOmzF4nHb+ZNB/DHHSIE/WtD2FW1frE=; b=EQcLbLfFSreWebnjScE7zT1T5CGRLLB08uh6Rytckgcgx2HNJMUhRMSN/wRPP6zOHi Jywy7sdBGcS37Oxc4FQ0eKcLcGKuBoOYCQ16D8TLEspn97khDAZ+BmocrUPA/WfIgZjh x1CHTYatBYVOsyhdFZj3yqxa8SmLKWGXeo1q22jQYmnqEryyzwI1RaIVD7d3ZZh4AAma RTihMrdYWKMMqp23gxs3G+P4ZPhIQ5696ZbwjEtXtOpzDSM5XUv/hTMYyjzqzyUW29O9 Qo983nKGa7GAXEyAbNEyrOj2roihuG9w3GcQGqmzKBLeyows/eFvLwzXPK3LXl0tbGVL MKaw== X-Gm-Message-State: AAQBX9dX0JiFPKMdFwFCUPpXhJAQy4RRFNpkIj4vnuMEpIV0rnQqHpqb MbowGBTsE25+zM3b8d8laYO/Gdzx/1E= X-Google-Smtp-Source: AKy350aWKg8kIKC0roeA72FaEe4HTb/wQtFuJp2chTATT/qvNt2jfzRorHJiQbnz3aOgwdrTNO7tZU5ONkg= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:9c3:b0:246:f8f7:f568 with SMTP id 61-20020a17090a09c300b00246f8f7f568mr2063266pjo.0.1681517167336; Fri, 14 Apr 2023 17:06:07 -0700 (PDT) Date: Fri, 14 Apr 2023 17:06:06 -0700 In-Reply-To: Mime-Version: 1.0 References: Message-ID: Subject: Re: [PATCH v7 00/14] KVM: mm: fd-based approach for supporting KVM guest private memory From: Sean Christopherson To: Ackerley Tng Cc: brauner@kernel.org, kirill.shutemov@linux.intel.com, chao.p.peng@linux.intel.com, hughd@google.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, qemu-devel@nongnu.org, linux-kselftest@vger.kernel.org, pbonzini@redhat.com, corbet@lwn.net, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, jlayton@kernel.org, bfields@fieldses.org, akpm@linux-foundation.org, shuah@kernel.org, rppt@kernel.org, steven.price@arm.com, mail@maciej.szmigiero.name, vbabka@suse.cz, vannapurve@google.com, yu.c.zhang@linux.intel.com, luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com, aarcange@redhat.com, ddutile@redhat.com, dhildenb@redhat.com, qperret@google.com, michael.roth@amd.com, mhocko@suse.com, songmuchun@bytedance.com, pankaj.gupta@amd.com, linux-arch@vger.kernel.org, arnd@arndb.de, linmiaohe@huawei.com, naoya.horiguchi@nec.com, tabba@google.com, wei.w.wang@intel.com Content-Type: text/plain; charset="us-ascii" Received-SPF: pass client-ip=2607:f8b0:4864:20::54a; envelope-from=3b-o5ZAYKClQE0w95y2AA270.yA8C08G-z0H079A929G.AD2@flex--seanjc.bounces.google.com; helo=mail-pg1-x54a.google.com X-Spam_score_int: -95 X-Spam_score: -9.6 X-Spam_bar: --------- X-Spam_report: (-9.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, USER_IN_DEF_DKIM_WL=-7.5 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Apr 14, 2023, Sean Christopherson wrote: > On Fri, Apr 14, 2023, Ackerley Tng wrote: > > Sean Christopherson writes: > > > if (WARN_ON_ONCE(file->private_data)) { > > > err = -EEXIST; > > > goto err_fd; > > > } > > > > Did you intend this as a check that the backing filesystem isn't using > > the private_data field in the mapping? > > > > I think you meant file->f_mapping->private_data. > > Ya, sounds right. I should have added disclaimers that (a) I wrote this quite > quickly and (b) it's compile tested only at this point. FWIW, here's a very lightly tested version that doesn't explode on a basic selftest. https://github.com/sean-jc/linux/tree/x86/upm_base_support