From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH v3 03/10] iommu/sva: Manage process address spaces
Date: Tue, 25 Sep 2018 15:26:27 +0200
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To: Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, Jean-Philippe Brucker <jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org>, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ilias.apalodimas-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, okaya-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, liguozhu-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org, christian.koenig-5C7GfCeVMHo@public.gmane.org, robin.murphy-5wv7dgnIgG8@public.gmane.org
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On Tue, Sep 25, 2018 at 11:15:40AM +0800, Lu Baolu wrote:
> This might be problematic for vt-d (and other possible arch's which use
> PASID other than SVA). When vt-d iommu works in scalable mode, a PASID
> might be allocated for:
> 
> (1) SVA
> (2) Device Assignable Interface (might be a mdev or directly managed
>     within a device driver).
> (3) SVA in VM guest
> (4) Device Assignable Interface in VM guest
> 
> So we can't expect that an io_mm pointer was associated with each PASID.
> And this code might run into problem if the pasid is allocated for
> usages other than SVA.

So all of these use-cases above should work in parallel on the same
device, just with different PASIDs? Or is a device always using only one
of the above modes at the same time?

Regards,

	Joerg