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([2001:b07:add:ec09:c399:bc87:7b6c:fb2a]) by smtp.googlemail.com with ESMTPSA id m36sm522420wms.25.2021.11.23.01.09.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 23 Nov 2021 01:09:41 -0800 (PST) Message-ID: <2f3e9d7e-ce15-e47b-54c6-3ca3d7195d70@redhat.com> Date: Tue, 23 Nov 2021 10:09:28 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Content-Language: en-US To: Chao Peng , "Kirill A. Shutemov" Cc: Wanpeng Li , jun.nakajima@intel.com, kvm@vger.kernel.org, david@redhat.com, qemu-devel@nongnu.org, "J . Bruce Fields" , dave.hansen@intel.com, "H . Peter Anvin" , ak@linux.intel.com, Jonathan Corbet , Joerg Roedel , x86@kernel.org, Hugh Dickins , Ingo Molnar , Borislav Petkov , luto@kernel.org, Thomas Gleixner , Andrew Morton , Jim Mattson , linux-mm@kvack.org, Sean Christopherson , susie.li@intel.com, Jeff Layton , linux-kernel@vger.kernel.org, john.ji@intel.com, Yu Zhang , linux-fsdevel@vger.kernel.org, Vitaly Kuznetsov , "Kirill A . Shutemov" References: <20211119134739.20218-1-chao.p.peng@linux.intel.com> <20211119134739.20218-14-chao.p.peng@linux.intel.com> <20211122141647.3pcsywilrzcoqvbf@box.shutemov.name> <20211123010639.GA32088@chaop.bj.intel.com> From: Paolo Bonzini Subject: Re: [RFC v2 PATCH 13/13] KVM: Enable memfd based page invalidation/fallocate In-Reply-To: <20211123010639.GA32088@chaop.bj.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: DDAEFF0001D5 X-Stat-Signature: nmpa9nrj59apta3uzqk4o7s5mh5ikubp Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=VQpajBwc; spf=pass (imf17.hostedemail.com: domain of paolo.bonzini@gmail.com designates 209.85.221.44 as permitted sender) smtp.mailfrom=paolo.bonzini@gmail.com; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=redhat.com (policy=none) X-HE-Tag: 1637658582-666605 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 11/23/21 02:06, Chao Peng wrote: >> Maybe the kvm has to be tagged with a sequential id that incremented every >> allocation. This id can be checked here. > Sounds like a sequential id will be needed, no existing fields in struct > kvm can work for this. There's no need to new concepts when there's a perfectly usable reference count. :) Paolo