From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752560AbbJHHmV (ORCPT ); Thu, 8 Oct 2015 03:42:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41151 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750967AbbJHHmB (ORCPT ); Thu, 8 Oct 2015 03:42:01 -0400 Date: Thu, 8 Oct 2015 10:41:53 +0300 From: "Michael S. Tsirkin" To: Gleb Natapov Cc: Avi Kivity , Alex Williamson , Vlad Zolotarov , Greg KH , linux-kernel@vger.kernel.org, hjk@hansjkoch.de, corbet@lwn.net, bruce.richardson@intel.com, avi@cloudius-systems.com, gleb@cloudius-systems.com, stephen@networkplumber.org, alexander.duyck@gmail.com Subject: Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support Message-ID: <20151008074153.GB19331@redhat.com> References: <20151006143821.GA11541@redhat.com> <5613DE26.1090202@cloudius-systems.com> <20151006174648-mutt-send-email-mst@redhat.com> <5613E75E.1040002@scylladb.com> <1444157480.4059.67.camel@redhat.com> <5614C11B.6090601@scylladb.com> <1444235464.4059.169.camel@redhat.com> <56154AB4.1050509@scylladb.com> <20151007230553-mutt-send-email-mst@redhat.com> <20151008041913.GB13818@scylladb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151008041913.GB13818@scylladb.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 08, 2015 at 07:19:13AM +0300, Gleb Natapov wrote: > Well > the alternative is to add /dev/vfio/nommu like you've said, but what > would be the difference between this and uio eludes me. Are you familiar with vfio that you ask such a question? Here's the vfio pci code: $ wc -l drivers/vfio/pci/* 27 drivers/vfio/pci/Kconfig 4 drivers/vfio/pci/Makefile 1217 drivers/vfio/pci/vfio_pci.c 1602 drivers/vfio/pci/vfio_pci_config.c 675 drivers/vfio/pci/vfio_pci_intrs.c 92 drivers/vfio/pci/vfio_pci_private.h 238 drivers/vfio/pci/vfio_pci_rdwr.c 3855 total There's some code dealing with iommu groups in drivers/vfio/pci/vfio_pci.c, but most of it is validating input and presenting a consistent interface to userspace. This is exactly what's missing here. There's also drivers/vfio/virqfd.c which deals with sending interrupts over eventfds correctly. -- MST