From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 24 Jun 2013 13:54:26 +1000 From: David Gibson To: Benjamin Herrenschmidt Subject: Re: [PATCH 3/4] KVM: PPC: Add support for IOMMU in-kernel handling Message-ID: <20130624035426.GE25265@voom.fritz.box> References: <1371653443.21896.291.camel@pasglop> <1371656989.22659.98.camel@ul30vt.home> <51C28BEA.8050501@ozlabs.ru> <20130620052822.GB3140@voom.redhat.com> <1371714449.3944.14.camel@pasglop> <51C2C1CC.9000003@ozlabs.ru> <1371740113.32709.22.camel@ul30vt.home> <20130622120304.GB25265@voom.fritz.box> <1371943693.3944.104.camel@pasglop> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="xA/XKXTdy9G3iaIz" In-Reply-To: <1371943693.3944.104.camel@pasglop> Cc: "kvm@vger.kernel.org mailing list" , Alexey Kardashevskiy , Joerg Roedel , Rusty Russell , Alexander Graf , kvm-ppc@vger.kernel.org, open list , Alex Williamson , Paul Mackerras , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --xA/XKXTdy9G3iaIz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jun 23, 2013 at 09:28:13AM +1000, Benjamin Herrenschmidt wrote: > On Sat, 2013-06-22 at 22:03 +1000, David Gibson wrote: > > I think the interface should not take the group fd, but the container > > fd. Holding a reference to *that* would keep the necessary things > > around. But more to the point, it's the right thing semantically: > >=20 > > The container is essentially the handle on a host iommu address space, > > and so that's what should be bound by the KVM call to a particular > > guest iommu address space. e.g. it would make no sense to bind two > > different groups to different guest iommu address spaces, if they were > > in the same container - the guest thinks they are different spaces, > > but if they're in the same container they must be the same space. >=20 > Interestingly, how are we going to extend that when/if we implement > DDW ? >=20 > DDW means an API by which the guest can request the creation of > additional iommus for a given device (typically, in addition to the > default smallish 32-bit one using 4k pages, the guest can request > a larger window in 64-bit space using a larger page size). So, would a PAPR gest requesting this expect the new window to have a new liobn, or an existing liobn? --=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 --xA/XKXTdy9G3iaIz Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iEYEARECAAYFAlHHwvIACgkQaILKxv3ab8ZVOQCdFa0KpJIGERzTedt0JRVzHMad +a4An30IO7PRSBaVjZgA2Is1VyepZ6V2 =wviw -----END PGP SIGNATURE----- --xA/XKXTdy9G3iaIz--