From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs Date: Thu, 13 May 2021 16:07:07 +1000 Message-ID: References: <20210427172432.GE1370958@nvidia.com> <20210429002149.GZ1370958@nvidia.com> <20210503160530.GL1370958@nvidia.com> <20210504181537.GC1370958@nvidia.com> <7e5c2276-ca1c-a8af-c15f-72a7c83c8bfa@ozlabs.ru> <20210505163902.GG1370958@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="/Mf++rjztzZShRAS" Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1620886032; bh=EDbwQxFNCJJrrEgHzT5gGi+1oWXpdmyJr1eJ+NUQ4bM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kWqsHMbOiAyxwLod+Rqt4KhSwB2oo0bV5TchI5WxvF3IL2lqztrJrQv615kgKUDnS rvOjRZCfVWenSYZrOWPrRga+vGFG2OWEIfQgUnlH6IFYpycIGoxJyhVRhtXU4RZ9Gc 02pKAkrH9LTvDiy9LdpyASoaGfwW0N2RNDDTSEfE= Content-Disposition: inline In-Reply-To: <20210505163902.GG1370958-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> List-ID: To: Jason Gunthorpe Cc: Alexey Kardashevskiy , Alex Williamson , "Liu, Yi L" , Jacob Pan , Auger Eric , Jean-Philippe Brucker , "Tian, Kevin" , LKML , Joerg Roedel , Lu Baolu , David Woodhouse , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , "cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Tejun Heo , Li Zefan , Johannes Weiner , Jean-Philippe Brucker , Jonathan Corbet , "Raj, Ashok" --/Mf++rjztzZShRAS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 05, 2021 at 01:39:02PM -0300, Jason Gunthorpe wrote: > On Wed, May 05, 2021 at 02:28:53PM +1000, Alexey Kardashevskiy wrote: >=20 > > This is a good feature in general when let's say there is a linux suppo= rted > > device which has a proprietary device firmware update tool which only e= xists > > as an x86 binary and your hardware is not x86 - running qemu + vfio in = full > > emulation would provide a way to run the tool to update a physical devi= ce. >=20 > That specific use case doesn't really need a vIOMMU though, does it? Possibly not, but the mechanics needed to do vIOMMU on different host IOMMU aren't really different from what you need for a no-vIOMMU guest. With a vIOMMU you need to map guest IOVA space into the host IOVA space. With no no-vIOMMU you need to map guest physical addresses into the host IOVA space. In either case the GPA/gIOVA to userspace and userspace to HPA mappings are basically arbitrary. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --/Mf++rjztzZShRAS Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAmCcwgsACgkQbDjKyiDZ s5JqLg/+Px9hBLz/IZ8N6Bl1BLwug0BbIEk1xxrBhtyubIdEbf6AuAkqa0HnxcSm EgS1KJ0eOe3yLUKaLskepCJDojbuqFYnLf1VTv3Uu0zp5AP8ggKQgfokxUVJdhpR aWMVjwOFAoUatYTP2umFN2ZfUsSxe/FsTkdTiAVApqn4AdTSlbGBvK+C4D7WPzZy 5rjVhgLfaQWJDGrTnhqCr4PJoz0z1FpOhzYXtpHR+u+d9BgDe2yj1gEFzICDk+UV 67QOqTNxWi1gSQ6uVa+xmB+xY0RZ7+x+fwObNBHrGWuFKJzwbf6aCQIprqEY5mro 9KAR0kP3LkywUN+rZjWQun9pXQdu/JWjZPtmdbm4rw+kIJEDdMk9TrOohOpjxUot 7vSoLVklFyMbnL84I3i7CELRxpkvtXaBd5VdGkEObg5nCcY8Fci8yLmhjOLXviGU iNmRCaiZikT+JKvnwiG7qIILT3DCA92Y+AiQYayPkmujhlmzxpFkyAM1Igh7EIfe a4O/U8qm61xxoTZhe+cbM11cIfiux8FwcxUrq54D1DCZstQ60IP/FaA4CQGSiBwm 55RNfJf+KFN9HG9hxH8BZYEGRtCYMuDfTjFdM0DaYHI8Rjv3X9MO4vuSI1tkoiQd kW7n1QyP2QKMzSHCJlE56aSa9T6HTtUetOuO3vAxirN9Z5/042I= =S/vm -----END PGP SIGNATURE----- --/Mf++rjztzZShRAS--