On Tue, Apr 14, 2015 at 02:32:26PM +0100, Varun Sethi wrote: > Hi Will, Hey Varun,
> > -----Original Message----- > > From: iommu-boun...@lists.linux-foundation.org [mailto:iommu- > > boun...@lists.linux-foundation.org] On Behalf Of Will Deacon > > Sent: Monday, April 13, 2015 4:11 PM > > To: Baptiste Reynal > > Cc: Linux IOMMU > > Subject: Re: SMMU 2-stage support > > > > On Fri, Apr 03, 2015 at 10:55:02AM +0100, Baptiste Reynal wrote: > > > We are eventually working on the vSMMU implementation. Relying on the > > > talk Will Deacon gave at the Linux Plumbers IOMMU Microconference on > > > October > > > 2014 (http://linuxplumbersconf.org/2014/ocw/proposals/2019), I tried > > > the vSMMU initialization. > > > > My position on the vSMMU still hasn't changed: > > > > > > Anyway, until somebody actually wants this feature I've put it on > > > > ice as it adds a whole bunch of complication to the ARM SMMU driver, > > > > as well as new user ABI extensions that I don't really want to maintain > > > > for > > fun. > > > > So, whilst it's great that you're looking at the code, I'm not very keen on > > merging anything until we have people committed to using it. Right now, the > > only feedback I've had has been going in the para-virt direction and I don't > > think we should do this "for fun". > Freescale would be interested in using the vSMMU implementation. We have > use cases for assigning devices to guest user space. Are you suggesting > that you are more inclined to using the para virtualized approach? I can see arguments either way; the vSMMU means that the guest can use the same SMMU driver as the host but a para-virtualised approach could theoretically be used across multiple SMMU implementations as well as potentially being kinder on the TLB. Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
