From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40493) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNwWS-0007jF-Jw for qemu-devel@nongnu.org; Tue, 26 Jan 2016 00:50:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aNwWR-0004v9-EZ for qemu-devel@nongnu.org; Tue, 26 Jan 2016 00:50:36 -0500 Date: Tue, 26 Jan 2016 16:41:29 +1100 From: David Gibson Message-ID: <20160126054129.GB16692@voom.fritz.box> References: <1453698952-32092-1-git-send-email-david@gibson.dropbear.id.au> <20160125111040.GH32205@voom.redhat.com> <56A68758.8090805@suse.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ADZbWkCsHQ7r3kzd" Content-Disposition: inline In-Reply-To: <56A68758.8090805@suse.de> Subject: Re: [Qemu-devel] [PATCH 00/10] Clean up page size handling for ppc 64-bit hash MMUs with TCG List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: lvivier@redhat.com, thuth@redhat.com, aik@ozlabs.ru, qemu-devel@nongnu.org, qemu-ppc@nongnu.org --ADZbWkCsHQ7r3kzd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 25, 2016 at 09:36:40PM +0100, Alexander Graf wrote: >=20 >=20 > On 01/25/2016 12:10 PM, David Gibson wrote: > >On Mon, Jan 25, 2016 at 04:15:42PM +1100, David Gibson wrote: > >>Encoding of page sizes on 64-bit hash MMUs for Power is rather arcane, > >>involving control bits in both the SLB and HPTE. At present we > >>support a few of the options, but far fewer than real hardware. > >> > >>We're able to get away with that in practice, because guests use a > >>device tree property to determine which page sizes are available and > >>we are setting that to match. However, the fact that the actual code > >>doesn't necessarily what we put into the table of available page sizes > >>is another ugliness. > >> > >>This series makes a number of cleanups to the page size handling. The > >>upshot is that afterwards the softmmu code operates off the same page > >>size encoding table that is advertised to the guests, ensuring that > >>they will be in sync. > >> > >>Finally, we extend the table of allowed sizes for POWER7 and POWER8 to > >>include the options allowed in hardware (including MPSS). We can fix > >>other hash MMU based CPUs in future if anyone cares enough. > >> > >>Please review, and I'll fold into ppc-for-2.6 for my next pull. > >Bother, somehow missed a serious bug in here that's causing > >oops-on-boot. Sorry, still tracking it down. >=20 > I still have no idea where your bug is (bisect probably should get you th= ere > pretty quick), Alas, no, because the bug only triggers once all the page sizes are added for POWER8 in the last patch. Luckily I found it anyway (see earlier reply). > but the overall concept sounds very reasonable to me. Please > benchmark performance before and after in the next cover letter also > :) Hrm.. as always the question is what benchmark? >=20 > Reviewed-by: Alexander Graf >=20 > Alex >=20 --=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 --ADZbWkCsHQ7r3kzd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWpwcJAAoJEGw4ysog2bOS67UQAKPRcZkJMkAfxoKvKmudBNVG tnpUZtOQ7q3mQph4pEIToxpDyYowCRW0ftnG6trshBUoifN6L60RXaRTnYxwHA1c koVjHUbENBnKIS8VUBKZDtNay0/jeqziTFhjwu6RWJQ6I+ayRC1Eaa2gpcEwfg7w r15nQ0mE7yi07fkiViQHUFtsPcNlsO0Yp5kPOsr5SjbZGGKPU17rKQkXwIZu64ZN /lL2VrMwHWfrL9TOQ2U4crV7aeMlq+x5p9NT1zo5Y8J43twHqr6jSkH5wEfFPT9I kQbI8LHq5ql1H2NOjXN1eytfpietW12tswluxggdTNvWtoWfgcUSDR6bsH311z5y IVPxk8xb65jP/ikSTbwFp5S/M2I1xuPBSoB3b1MTbWGQRPZQOQ/uafwwJt2PuaWW /DkosffPZCZWLlVdPxv3mHjDughTV6ectVkKy/AaVRGcc06JUpchdPYIYv/m6IeE 3VEeTlGZG/4tzwfQ74lkWVk9jX9psUk+6Tj+cCAytwYFRchdauWgSX+tHdKL0b31 I4cZm/YaaY9jWfvxxd2cysmWBIsYP0212uYaXB8935Uj289zIcTpXI+B1NLvaOpH 3i3m2eollO/MYdBWJYRFG1tJxRqg4SPd41X1ARsXJHM0PI+j8E62saUU0+RqHT2m MiGuNR5A6QmkAyS64Fly =27NO -----END PGP SIGNATURE----- --ADZbWkCsHQ7r3kzd--