From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Wang Subject: Re: [PATCH 0 of 6 V6] amd iommu: support ats/gpgpu passthru on iommuv2 systems Date: Wed, 14 Mar 2012 15:48:28 +0100 Message-ID: <4F60AFBC.5020007@amd.com> References: <1331734152.23971.449.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1331734152.23971.449.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: "Keir (Xen.org)" , "xen-devel@lists.xensource.com" , Ian Jackson , "JBeulich@suse.com" List-Id: xen-devel@lists.xenproject.org On 03/14/2012 03:09 PM, Ian Campbell wrote: > On Thu, 2012-03-08 at 13:21 +0000, Wei Wang wrote: >> Hi, >> This is patch set v6. It includes all pending patches that are needed to enable gpgpu passthrough > > I'm curious, is any of this actually specific to GPGPU passthrough or is > it just that GPGPU passthrough happens to be the main (only?) reason you > would want to expose a virtualised IOMMU to the guest OS? Are there any > other use cases? > > Ian. > > > For now, gpgpu is the only use case. But actually any sophisticated ats devices that supports PASID and PRI capabilities will need to work with iommuv2 driver in guest OS, so they will also need a virtual iommu in guest space. Please check ats spec 1.1, those capabilities have been documented and they are not specific to GPGPU. Thanks, Wei