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: Wed, 6 Feb 2019 12:18:00 +1100 Message-ID: <20190206011800.GN22661@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> <20190204053610.GK1927@umbus.fritz.box> <20190205221315.GB29038@blackberry> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="o+ZCuNqY+dEAKBWl" Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, =?iso-8859-1?Q?C=E9dric?= Le Goater , linuxppc-dev@lists.ozlabs.org To: Paul Mackerras Return-path: Content-Disposition: inline In-Reply-To: <20190205221315.GB29038@blackberry> 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 --o+ZCuNqY+dEAKBWl Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 06, 2019 at 09:13:15AM +1100, Paul Mackerras wrote: > On Tue, Feb 05, 2019 at 12:31:28PM +0100, C=E9dric Le Goater wrote: > > >>> As for nesting, I suggest for the foreseeable future we stick to XI= CS > > >>> emulation in nested guests. > > >> > > >> ok. so no kernel_irqchip at all. hmm.=20 > >=20 > > I was confused with what Paul calls 'XICS emulation'. It's not the QEMU > > XICS emulated device but the XICS-over-XIVE KVM device, the KVM XICS=20 > > device KVM uses when under a P9 processor.=20 >=20 > Actually there are two separate implementations of XICS emulation in > KVM. The first (older) one is almost entirely a software emulation > but does have some cases where it accesses an underlying XICS device > in order to make some things faster (IPIs and pass-through of a device > interrupt to a guest). The other, newer one is the XICS-on-XIVE > emulation that Ben wrote, which uses the XIVE hardware pretty heavily. > My patch was about making the the older code work when there is no > XICS available to the host. Ah, right. To clarify my earlier statements in light of this: * We definitely want some sort of kernel-XICS available in a nested guest. AIUI, this is now accomplished, so, Yay! * Implementing the L2 XICS in terms of L1's PAPR-XIVE would be a bonus, but it's a much lower priority. --=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 --o+ZCuNqY+dEAKBWl Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAlxaNcYACgkQbDjKyiDZ s5KMFA/9Ea25W4mwq61gaNMyUtvsa8KqPjL4f5PryrwBCsCXdxwnV+gyiT/mCOdC djMYoagDTYGqbk5y2I4XDODaF9znNDirLIGOEZPtB1KNzPsK65BOvNaSiGNFXJW+ ZQ6aNEQX1xaoGwqXZ2MAcuMLQtYrD4RAZ+HwHY15unnd1JMecOCbWsDRYF+/hjq9 AOi3Rb+K7Z2vQb8rr+kgzMFyxCVx6gD0G9oTX283RhWjliqom2wXlTpCv5cd1aAK mNeJzNVoPFblIH0B/hj/aXWaTInRmkPtuV28nFCRaNROZNkYh/LweOdHGvdo5/E8 A+4Yzsmn2IUILglriy/I3JF2MhCaIReXLBCXct3mQKOsPGSmUPGfS7iCHfYAA5b2 6eiqkN4gUplxtOuyVIHj/bNgnfVgeJUkWVF67RDfw26FS0EumPb/Hl247c+6W+LS U1fS9+0TgDUCjDn33zZuTJT5NrXjOeCzYtap3x8LbbtIykugBQUN6E4vlh2rYCON +oOyZK3ETZ4tqjYhajzdoBQOehGIDvntg6m8/Jqncf+0lVVF3wJHBCwwqxSzUnRj mzRlxUNJA16Wn0q+ZUFu0USbuJletsfqIZmhT45G+Fls51BidrQMu+gp+y0T9eem KXAIwlOKCtQ4BQirKplzXuHKRJU/3qUKlSWcjwY6OO9/5Yih8Rs= =gIj3 -----END PGP SIGNATURE----- --o+ZCuNqY+dEAKBWl--