From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59326) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxSAf-0005XB-Sy for qemu-devel@nongnu.org; Tue, 26 May 2015 23:38:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YxSAb-0001LF-Ok for qemu-devel@nongnu.org; Tue, 26 May 2015 23:38:21 -0400 Date: Wed, 27 May 2015 12:54:19 +1000 From: David Gibson Message-ID: <20150527025419.GB32733@voom.redhat.com> References: <1429964684-23872-1-git-send-email-aik@ozlabs.ru> <1429964684-23872-7-git-send-email-aik@ozlabs.ru> <55633A54.8080807@ozlabs.ru> <20150526024628.GA30620@voom.redhat.com> <5564359A.2070009@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="98e8jtXdkpgskNou" Content-Disposition: inline In-Reply-To: <5564359A.2070009@redhat.com> Subject: Re: [Qemu-devel] [PATCH qemu v7 06/14] spapr_iommu: Introduce "enabled" state for TCE table List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Alexander Graf , Alexey Kardashevskiy , Michael Roth , qemu-devel@nongnu.org, Alex Williamson , qemu-ppc@nongnu.org --98e8jtXdkpgskNou Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 26, 2015 at 10:58:02AM +0200, Paolo Bonzini wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 >=20 >=20 >=20 > On 26/05/2015 04:46, David Gibson wrote: > > On Tue, May 26, 2015 at 01:05:56AM +1000, Alexey Kardashevskiy=20 > > wrote: > >> Hi Paolo, > >>=20 > >> I have had a conversation with Mike and it turns out I am not=20 > >> allowed to create/remove memory regions dynamically=20 > >> (docs/memory.txt:101); otherwise "destroying regions during > >> reset causes assertion in RCU thread during PHB/IOMMU > >> unplug/unparent". Is it because patch just missing some > >> unref()/unparent() call or it is totally wrong and I have to > >> implement subregions (on a PCI bus address space) myself if I > >> want dynamic DMA windows? Thanks! >=20 > I'm blind, can you explain the path where that happens? >=20 > > So, the sentences after that one note an exception for alias and=20 > > container regions. I think iommu regions should behave similarly > > - in a sense they're just a procedurally generated collection of=20 > > alias regions. >=20 > The difference is that containers and aliases are resolved at the time > the memory region tree is flattened, while IOMMU regions are resolved > at run time. >=20 > > If it's not true now that they can be unparented at any time like=20 > > alias regions, we should probably try to make it true. >=20 > Unfortunately it's not so easy... Ah, yeah, drat. --=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 --98e8jtXdkpgskNou Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIbBAEBAgAGBQJVZTHbAAoJEGw4ysog2bOSPm0P+Oz6CpXBIirp1AdDdVJi1ML5 ummtJTLvXeupWqQOMl8P3Tb1RdSuRmq6K96ppmcs/kJ9EDrtNMY9SUpmdgSWN0ue pZg4erFmEKeoqARbXaOiczQfDacRFssMdlevw+C/7cJKSsBgKeVR0RoUdl/fACtU NelQ3touF3WotARWemZmk43zPecj6K2sVtOQ2xqsMmh2DnI+v5popNxfziV5/iMY N9E6oY2TdjdE+Ep4U86NKZ9xi4rdX8Y5ib56AxUj0y9yhYxke+spkas1pyzcDlSL /nggszoO9tuptAOzwL2CNdrec0Lkuq/2yJ+TaCPrvquHrb600tusE4q508oI0cPH 9asw9kHNiJMTlQWgDXQBYxkXJvHAf78QB+bNrxf2QqybW4UFXuJqCnzV9B2CeFNP kVk1FdHlLqUwYSaW4TziExgdWMPrK5uEydI/7M/XL6q7c0xAGEXsdcMaeTHtUfRB dlOGNgSxcf0WL3Lfnf7xFMCxaYRvZY6XGsnBoSQ2HgpIgsPaK6SQ6qsNc4enYzOs jo9I+l44PcgKKkX65U42uPjA3FQ//IK36/AkGSy8+rOHEVtSQsQlNOisYqCIzkK/ mq6J9HeqORdJrz9T//Qx6gr6+mpv02IltquNz5GqfcmqOe/dww1hTFtU9gRRAQDY 6R/tV6qbJj3E6MTCS5E= =KC1w -----END PGP SIGNATURE----- --98e8jtXdkpgskNou--