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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5974AC07E9D for ; Mon, 26 Sep 2022 14:09:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7C29E8E0058; Mon, 26 Sep 2022 10:09:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 748708E0047; Mon, 26 Sep 2022 10:09:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 59C408E0058; Mon, 26 Sep 2022 10:09:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 4360A8E0047 for ; Mon, 26 Sep 2022 10:09:41 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 179A8160C3E for ; Mon, 26 Sep 2022 14:09:41 +0000 (UTC) X-FDA: 79954419762.10.647E22A Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by imf07.hostedemail.com (Postfix) with ESMTP id 355BC40018 for ; Mon, 26 Sep 2022 14:09:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664201380; x=1695737380; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=kLBWR5qEV1U14bOBHrdj86S+fx8bShjKVx0oSvRe47k=; b=L5lrO0HKTdjfsgzoczFWPppt9Uvqqja3xOIK8pNq4duKQKqSNpPtfzT9 OkSVhRRUtOSiCro3VeabrMhXmVj1p7WRgUOJW+7hymiUurH03EDGqsXwm +/Uo7qxGNozD3TSeryP0XYyPBusX46izb4La8Fv3zdgjrEBgEXP8cLt3a oFPGwdjwttY8i89/X/S/6TMe7XmzyB82NPWBi9I7FMyYplY/dRypp9r6G tjIEPlWpbXYijMVCBhjrlnmyolZHXbi5ijRJXVvGRE+ZPUWFANF0UrY4h 7krcFj0jIE8fSpGbmf6aF4L8yH4xTQYTapmTMys6IVUSYXYUxTYZMU5Xn A==; X-IronPort-AV: E=McAfee;i="6500,9779,10482"; a="327387502" X-IronPort-AV: E=Sophos;i="5.93,346,1654585200"; d="scan'208";a="327387502" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Sep 2022 07:09:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10482"; a="651840417" X-IronPort-AV: E=Sophos;i="5.93,346,1654585200"; d="scan'208";a="651840417" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.193.75]) by orsmga008.jf.intel.com with ESMTP; 26 Sep 2022 07:09:28 -0700 Date: Mon, 26 Sep 2022 22:04:51 +0800 From: Chao Peng To: Fuad Tabba Cc: 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, 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 , Shuah Khan , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , "Kirill A . Shutemov" , 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, Quentin Perret , Michael Roth , mhocko@suse.com, Muchun Song , wei.w.wang@intel.com Subject: Re: [PATCH v8 2/8] KVM: Extend the memslot to support fd-based private memory Message-ID: <20220926140451.GA2658254@chaop.bj.intel.com> Reply-To: Chao Peng References: <20220915142913.2213336-1-chao.p.peng@linux.intel.com> <20220915142913.2213336-3-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664201380; h=from:from:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=U9s768cVE6V+EGMPk6A6KyhxWsgDnVllkPNP7U3f9go=; b=INeBwyZmL13TzJmpX0QisCmvzNwXNPZjtspGXzDKYbbd1kqw7kj4vMn5jCZAUdjlb29Dae 0IgOn1W0stDGnGZz5X7LbwX2DR6P8zDHAB8iWat3T0zjiDfe8caIszEcq6YAmGj5cY8oSg IXCrb92mEtZDdrmYrnT22Vxahvg9XWs= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=L5lrO0HK; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none); spf=none (imf07.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 192.55.52.88) smtp.mailfrom=chao.p.peng@linux.intel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664201380; a=rsa-sha256; cv=none; b=5U/K6okf2md0LVjtMnGLHoPAuV+eFl7/f+XCU5vrXo9q6uUNz3Ta/Um0H7acxKCsJmuSV0 qjDif1ZWQFrxevlqyvOygKRa/H/gCOGdTLyN/fbmYiml6EFJzw7eXy3Dn6FGX8apXSdYZo SVCl610c+ZRxA/e3YdSyS9z0DkE0X4c= X-Rspam-User: X-Rspamd-Queue-Id: 355BC40018 X-Rspamd-Server: rspam01 X-Stat-Signature: jnrcd5k8qdggi3swuxjx6ck6tk1u9o9y Authentication-Results: imf07.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=L5lrO0HK; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none); spf=none (imf07.hostedemail.com: domain of chao.p.peng@linux.intel.com has no SPF policy when checking 192.55.52.88) smtp.mailfrom=chao.p.peng@linux.intel.com X-HE-Tag: 1664201379-364169 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: On Mon, Sep 26, 2022 at 11:26:45AM +0100, Fuad Tabba wrote: ... > > + > > +- KVM_MEM_PRIVATE can be set to indicate a new slot has private memory backed by > > + a file descirptor(fd) and the content of the private memory is invisible to > > s/descirptor/descriptor Thanks. ... > static long kvm_vm_ioctl(struct file *filp, > > unsigned int ioctl, unsigned long arg) > > { > > @@ -4645,14 +4672,20 @@ static long kvm_vm_ioctl(struct file *filp, > > break; > > } > > case KVM_SET_USER_MEMORY_REGION: { > > - struct kvm_userspace_memory_region kvm_userspace_mem; > > + struct kvm_user_mem_region mem; > > + unsigned long size = sizeof(struct kvm_userspace_memory_region); > > nit: should this be sizeof(struct mem)? That's more similar to the > existing code and makes it dependent on the size of mem regardless of > possible changes to its type in the future. Unluckily no, the size we need copy_from_user() depends on the flags, e.g. without KVM_MEM_PRIVATE, we can't safely copy that big size since the 'extended' part may not even exist. > > > + > > + kvm_sanity_check_user_mem_region_alias(); > > > > r = -EFAULT; > > - if (copy_from_user(&kvm_userspace_mem, argp, > > - sizeof(kvm_userspace_mem))) > > + if (copy_from_user(&mem, argp, size); > > It gets fixed in a future patch, but the ; should be a ). Good catch, thanks! Chao > > Cheers, > /fuad