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[142.68.128.5]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6cb9359c01esm6550426d6.2.2024.10.03.06.36.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Oct 2024 06:36:58 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.95) (envelope-from ) id 1swM0o-00ASYX-0T; Thu, 03 Oct 2024 10:36:58 -0300 Date: Thu, 3 Oct 2024 10:36:58 -0300 From: Jason Gunthorpe To: James Gowans Cc: linux-kernel@vger.kernel.org, Kevin Tian , Joerg Roedel , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Will Deacon , Robin Murphy , Mike Rapoport , "Madhavan T. Venkataraman" , iommu@lists.linux.dev, Sean Christopherson , Paolo Bonzini , kvm@vger.kernel.org, David Woodhouse , Lu Baolu , Alexander Graf , anthony.yznaga@oracle.com, steven.sistare@oracle.com, nh-open-source@amazon.com, "Saenz Julienne, Nicolas" Subject: Re: [RFC PATCH 12/13] iommufd, guestmemfs: Ensure persistent file used for persistent DMA Message-ID: <20241003133658.GC2456194@ziepe.ca> References: <20240916113102.710522-1-jgowans@amazon.com> <20240916113102.710522-13-jgowans@amazon.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240916113102.710522-13-jgowans@amazon.com> On Mon, Sep 16, 2024 at 01:31:01PM +0200, James Gowans wrote: > +#ifdef CONFIG_GUESTMEMFS_FS > + struct vm_area_struct *vma; > + struct mm_struct *mm = current->mm; > + > + mmap_read_lock(mm); > + vma = find_vma_intersection(current->mm, > + cmd->user_va, cmd->user_va + cmd->length); > + if (!vma || !is_guestmemfs_file(vma->vm_file)) { > + mmap_read_unlock(mm); > + return -EFAULT; > + } > + mmap_read_unlock(mm); > +#else Any kind of FD interaction needs to go through the new FD path that Steve is building: https://lore.kernel.org/linux-iommu/1727190338-385692-1-git-send-email-steven.sistare@oracle.com I'm expecting multiple kinds of fds to fall into that pattern, including memfs, guestmemfd, and dmabuf. guestmemfd can just be one more.. Jason