From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gavin Shan Date: Mon, 19 May 2014 23:54:20 +0000 Subject: Re: [PATCH 2/8] powerpc/eeh: Info to trace passed devices Message-Id: <20140519235420.GA7042@shangw> List-Id: References: <1400040722-29608-1-git-send-email-gwshan@linux.vnet.ibm.com> <1400040722-29608-3-git-send-email-gwshan@linux.vnet.ibm.com> <5379FD19.2020100@suse.de> <1400539049.3986.71.camel@pasglop> In-Reply-To: <1400539049.3986.71.camel@pasglop> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Benjamin Herrenschmidt Cc: aik@ozlabs.ru, Alexander Graf , kvm-ppc@vger.kernel.org, Gavin Shan , alex.williamson@redhat.com, qiudayu@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org On Tue, May 20, 2014 at 08:37:29AM +1000, Benjamin Herrenschmidt wrote: >On Mon, 2014-05-19 at 14:46 +0200, Alexander Graf wrote: >> I don't see the point of VFIO knowing about guest addresses. They are >> not unique across a system and the whole idea that a VFIO device has to >> be owned by a guest is also pretty dubious. >> >> I suppose what you really care about here is just a token for a specific >> device? But why do you need one where we don't have tokens yet? > >I think this is going to be needed when doing in-kernel acceleration >of some of the RTAS calls, but yes, Gavin, why do we need that now ? > Thanks for your comments :-) For now, the newly introduced IOCTL command (VFIO_EEH_INFO) is handled by VFIO-Container fd, which can't identify IOMMU group (PE) or VFIO-PCI-dev naturally because one VFIO-container can have multiple IOMMU groups docked there. I'm going to let VFIO-PCI-dev fd handle the IOCTL command because VFIO-PCI-dev fd can identify the device and the corresponding IOMMU group (PE). With that, the address mapping stuff isn't necessary. Thanks, Gavin