From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adShe-0004TN-Lk for qemu-devel@nongnu.org; Tue, 08 Mar 2016 20:14:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1adShb-0003k5-C5 for qemu-devel@nongnu.org; Tue, 08 Mar 2016 20:14:18 -0500 Date: Wed, 9 Mar 2016 12:04:10 +1100 From: David Gibson Message-ID: <20160309010410.GG22546@voom.fritz.box> References: <1456969373-6741-1-git-send-email-aik@ozlabs.ru> <20160304033926.GV1620@voom.redhat.com> <56D90B58.9000803@ozlabs.ru> <56DE13DB.7020000@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="evOcBaiMpN7OEvsd" Content-Disposition: inline In-Reply-To: <56DE13DB.7020000@ozlabs.ru> Subject: Re: [Qemu-devel] [PATCH qemu] spapr-pci: Make MMIO spacing a machine property and increase it List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf --evOcBaiMpN7OEvsd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Mar 08, 2016 at 10:50:51AM +1100, Alexey Kardashevskiy wrote: > On 03/04/2016 03:13 PM, Alexey Kardashevskiy wrote: > >On 03/04/2016 02:39 PM, David Gibson wrote: > >>On Thu, Mar 03, 2016 at 12:42:53PM +1100, Alexey Kardashevskiy wrote: > >>>The pseries machine supports multiple PHBs. Each PHB's MMIO/IO space is > >>>mapped to the CPU address space starting at SPAPR_PCI_WINDOW_BASE plus > >>>some offset which is calculated from PHB's index and > >>>SPAPR_PCI_WINDOW_SPACING which is defined now as 64GB. > >>> > >>>Since the default 32bit DMA window is using first 2GB of MMIO space, > >>>the amount of MMIO which the PCI devices can actually use is reduced > >>>to 62GB. This is a problem if the user wants to use devices with > >>>huge BARs. > >>> > >>>For example, 2 PCI functions of a NVIDIA K80 adapter being passed thro= ugh > >>>will exceed this limit as they have 16M + 16G + 32M BARs which > >>>(when aligned) will need 64GB. > >>> > >>>This converts SPAPR_PCI_WINDOW_BASE and SPAPR_PCI_WINDOW_SPACING to > >>>sPAPRMachineState properties. This uses old values for pseries machine > >>>before 2.6 and increases the spacing to 128GB so MMIO space becomes 12= 6GB. > >>> > >>>This changes the default value of sPAPRPHBState::mem_win_size to -1 for > >>>pseries-2.6 and adds setup to spapr_phb_realize. > >>> > >>>Signed-off-by: Alexey Kardashevskiy > >> > >>So, in theory I dislike the spapr_pci device reaching into the machine > >>type to get the spacing configuration. But.. I don't know of a better > >>way to achieve the desired outcome. > > > > > >We could drop @index and spacing; and request the user to specify the MM= IO > >window start (at least) for every additional PHB. >=20 > So what is the decision? :) There isn't one. I really don't know how to handle this, trying to talk to some people for ideas. --=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 --evOcBaiMpN7OEvsd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJW33aKAAoJEGw4ysog2bOSM8cQAMoS/sk1/P82GIP2AAMiwOI3 8meh4xoHbfRCGO9mjkQtqnuBlezJTYX4WNP8YEjSWlfyAtFtWdAdN8yt0VzCilT2 imRSW8+BqW3xpuiAmSfH3rmfg/eppfjk9IOMDWftaXcXT2yzCImM33MMYrE3BLiT X4R0hENYIAPIoe25RHmJByO56mOaa3lSRv6SFUcnnWDEyn/ZfEHJjFn/G08vdInl tgsWbiwDqBNe/Qu89WO6w2NaiSTiLmQEfr5bRPrYvUcBXTueHZX3F9+kHDl9oPhP AXDGTE6SHzQ7NBEl4a7nXwRg5zNZxTYWGFEkbQTbH6XAv3z9p0K41u50w+MxAUwW gRtuSRNgtLa6JaR/m16hi/k43DJunmA3ltRLpoQKONNuyKsu/sLiLvcmef+5Frlt qTVb6lN84ZvGq+TFgk4lMWu+V/kHNE67jUw0/gx92cfHYtcLD9v1lNUfkQF0P1yk J1s5uVhW+rWYlL6njmCpgspmyWxtfSbfCrjxZsgsBQhckRtMLdV++20DhLcBUbcx 9A9cN6lLiQGn1DQpy/Q4unbbvtXOO9bznuiOJW34elizRPsmtHvfM5bKRKWhozDx tF5E4wxOErWNR5XAe01jri7fjtawS6qmI+xbZlhMg161aqWaNNChMs03UigOjbZN 7IddrXP6ySk57GbcZjbU =6pQ3 -----END PGP SIGNATURE----- --evOcBaiMpN7OEvsd--