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[142.162.113.129]) by smtp.gmail.com with ESMTPSA id x21sm6354233qkf.77.2021.11.23.09.17.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Nov 2021 09:17:23 -0800 (PST) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1mpZQ3-000Dij-2a; Tue, 23 Nov 2021 13:17:23 -0400 Date: Tue, 23 Nov 2021 13:17:23 -0400 From: Jason Gunthorpe To: Paolo Bonzini Cc: David Hildenbrand , Chao Peng , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.org, 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 , "Kirill A . Shutemov" , luto@kernel.org, john.ji@intel.com, susie.li@intel.com, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com Subject: Re: [RFC v2 PATCH 01/13] mm/shmem: Introduce F_SEAL_GUEST Message-ID: <20211123171723.GD5112@ziepe.ca> References: <20211119134739.20218-1-chao.p.peng@linux.intel.com> <20211119134739.20218-2-chao.p.peng@linux.intel.com> <20211119151943.GH876299@ziepe.ca> <6de78894-8269-ea3a-b4ee-a5cc4dad827e@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6de78894-8269-ea3a-b4ee-a5cc4dad827e@redhat.com> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: ABD8A508BB94 X-Stat-Signature: butimoskasa8n3bmhjmry36ayra8i3j6 Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=ziepe.ca header.s=google header.b=HM1ELBL6; spf=pass (imf01.hostedemail.com: domain of jgg@ziepe.ca designates 209.85.219.45 as permitted sender) smtp.mailfrom=jgg@ziepe.ca; dmarc=none X-HE-Tag: 1637687841-982142 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 Tue, Nov 23, 2021 at 10:06:02AM +0100, Paolo Bonzini wrote: > I think it's great that memfd hooks are usable by more than one subsystem, > OTOH it's fair that whoever needs it does the work---and VFIO does not need > it for confidential VMs, yet, so it should be fine for now to have a single > user. I think adding a new interface to a core kernel subsystem should come with a greater requirement to work out something generally useful and not be overly wedded to a single use case (eg F_SEAL_GUEST) Especially if something like 'single user' is not just a small implementation artifact but a key design tennant of the whole eventual solution. Jason