From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [PATCH 00/19] KVM: PPC: Book3S HV: add XIVE native exploitation mode Date: Mon, 4 Feb 2019 16:36:10 +1100 Message-ID: <20190204053610.GK1927@umbus.fritz.box> References: <20190107184331.8429-1-clg@kaod.org> <20190122044654.GA15124@blackberry> <2f9b4420-ef90-20b8-d31b-dc547a6aa6b4@kaod.org> <06b7c4d2-72ba-ca4f-aded-789280798136@kaod.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="d6d1KVhp94hk3Jrm" Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org To: =?iso-8859-1?Q?C=E9dric?= Le Goater Return-path: Content-Disposition: inline In-Reply-To: <06b7c4d2-72ba-ca4f-aded-789280798136@kaod.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" List-Id: kvm.vger.kernel.org --d6d1KVhp94hk3Jrm Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jan 26, 2019 at 09:25:04AM +0100, C=E9dric Le Goater wrote: > Was there a crashing.org shutdown ?=20 >=20 > Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) > by in5.mail.ovh.net (Postfix) with ESMTPS id 43mYnj0nrlz1N7KC > for ; Fri, 25 Jan 2019 22:38:00 +0000 (UTC) > Received: from localhost (localhost.localdomain [127.0.0.1]) > by gate.crashing.org (8.14.1/8.14.1) with ESMTP id x0NLZf4K021092; > Wed, 23 Jan 2019 15:35:43 -0600 >=20 >=20 > On 1/23/19 10:35 PM, Benjamin Herrenschmidt wrote: > > On Wed, 2019-01-23 at 20:07 +0100, C=E9dric Le Goater wrote: > >> Event Assignment Structure, a.k.a IVE (Interrupt Virtualization Entry) > >> > >> All the names changed somewhere between XIVE v1 and XIVE v2. OPAL and > >> Linux should be adjusted ... > >=20 > > All the names changed between the HW design and the "architecture" > > document. The HW guys use the old names, the architecture the new > > names, and Linux & OPAL mostly use the old ones because frankly the new > > names suck big time. >=20 > Well, It does not make XIVE any clearer ... I did prefer the v1 names > but there was some naming overlap in the concepts.=20 >=20 > >> It would be good to talk a little about the nested support (offline=20 > >> may be) to make sure that we are not missing some major interface that= =20 > >> would require a lot of change. If we need to prepare ground, I think > >> the timing is good. > >> > >> The size of the IRQ number space might be a problem. It seems we=20 > >> would need to increase it considerably to support multiple nested=20 > >> guests. That said I haven't look much how nested is designed. =20 > >=20 > > The size of the VP space is a bigger concern. Even today. We really > > need qemu to tell the max #cpu to KVM so we can allocate less of them. >=20 > ah yes. we would also need to reduce the number of available priorities= =20 > per CPU to have more EQ descriptors available if I recall well.=20 >=20 > > As for nesting, I suggest for the foreseeable future we stick to XICS > > emulation in nested guests. >=20 > ok. so no kernel_irqchip at all. hmm. =20 That would certainly be step 0, making sure the capability advertises this correctly. I think we do want to make XICs-on-XIVE emulation work in a KVM L1 (so we'd need to have it make XIVE hcalls to the L0 instead of OPAL calls). XIVE-on-XIVE for L1 would be nice too, which would mean implementing the XIVE hcalls from the L2 in terms of XIVE hcalls to the L0. I think it's ok to delay this indefinitely as long as the caps advertise correctly so that qemu will use userspace emulation until its ready. > I was wondering how possible it was to have L2 initialize the underlying= =20 > OPAL structures in the L0 hypervisor. May be with a sort of proxy hcall= =20 > which would perform the initialization in QEMU L1 on behalf of L2. >=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 --d6d1KVhp94hk3Jrm Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAlxXz0oACgkQbDjKyiDZ s5IIqQ//T4mY2mR8V5zvfzz59IoHL4G1+V97HmzSqSWOQxYe+W4V4+9/tjvCPlF2 aUY8VZP6IDrZjND4GWk8mx1YMZ+aHYwf2sB6tNnUnXykBVfwOQMPSBKsNJB20TM6 IRSnyP6VFFbMM5c2fmNVhyt3l6iWvcxvsC3f9TonoGDB9xAETr9fg+P4kTnbExXg uZYbuh+Plam1fncLzaxXiAvLrmA4nHt7sjRB6DAMjOEfWY7M4xfySl27zDLDBBFg TSYhOfVP1TEkP2ML6126BW1FPdS7uBxwZd/cM/m95rLOiZrSGEqATPZrCZiB/GYa WHH2Vy/UOOEEfbHGDEKjgl5H0oVf86g8AeRgJJ8F0t2S+08QzTQVpWiHCJDjrOAp 6YjmdmPmgo3DATWvZADBx97Wc+j9FT5YENlh3L9GtvTMp96OUhv3jIQL96O1U+Ck FZ2Q0RMJh9iT9qJpSzIcAfON04WZhYTN+D5EI76RyXcv9lA/1/u0lSbv/Zn304cG QQXhrYrsZSpHXL0vD+NTA39UnERKNpFICcNADpExFwGZloJaGKBTR0p3bLLP8GeA e8t0PtrOJPOp0kQAc6BxO8QQKXdrmSjE5RoygC7czzvAj3cyn8JoOz4XquQ2J9Fs 4x+NwDNxkMnJzT/9S8VYe5+t+P2pPAKb0/wakmDORSVCb83Jq7s= =w1Yu -----END PGP SIGNATURE----- --d6d1KVhp94hk3Jrm--