From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:42528 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726473AbfKNQDa (ORCPT ); Thu, 14 Nov 2019 11:03:30 -0500 Date: Thu, 14 Nov 2019 17:03:13 +0100 From: Cornelia Huck Subject: Re: [RFC 17/37] DOCUMENTATION: protvirt: Instruction emulation Message-ID: <20191114170313.3606d554.cohuck@redhat.com> In-Reply-To: References: <20191024114059.102802-1-frankja@linux.ibm.com> <20191024114059.102802-18-frankja@linux.ibm.com> <20191114161526.1100f4fe.cohuck@redhat.com> <20191114162024.13f17aa9@p-imbrenda.boeblingen.de.ibm.com> <20191114164136.0be3f058.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/7N204=Db5u+575pzVvjR10_"; protocol="application/pgp-signature"; micalg=pgp-sha256 Sender: linux-s390-owner@vger.kernel.org List-ID: To: Janosch Frank Cc: Claudio Imbrenda , kvm@vger.kernel.org, linux-s390@vger.kernel.org, thuth@redhat.com, david@redhat.com, borntraeger@de.ibm.com, mihajlov@linux.ibm.com, mimu@linux.ibm.com, gor@linux.ibm.com --Sig_/7N204=Db5u+575pzVvjR10_ Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 14 Nov 2019 16:55:46 +0100 Janosch Frank wrote: > On 11/14/19 4:41 PM, Cornelia Huck wrote: > > On Thu, 14 Nov 2019 16:20:24 +0100 > > Claudio Imbrenda wrote: > > =20 > >> On Thu, 14 Nov 2019 16:15:26 +0100 > >> Cornelia Huck wrote: > >> =20 > >>> On Thu, 24 Oct 2019 07:40:39 -0400 > >>> Janosch Frank wrote: > >>>> +The Secure Instruction Data Area contains instruction storage > >>>> +data. Data for diag 500 is exempt from that and has to be moved > >>>> +through shared buffers to KVM. =20 > >>> > >>> I find this paragraph a bit confusing. What does that imply for diag > >>> 500 interception? Data is still present in gprs 1-4? =20 > >> > >> no registers are leaked in the registers. registers are always only > >> exposed through the state description. =20 > >=20 > > So, what is so special about diag 500, then? =20 >=20 > That's mostly a confusion on my side. > The SIDAD is 4k max, so we can only move IO "management" data over it > like ORBs and stuff. My intention was to point out, that the data which > is to be transferred (disk contents, etc.) can't go over the SIDAD but > needs to be in a shared page. >=20 > diag500 was mostly a notification mechanism without a lot of data, right? Yes; the main information in there are the schid identifying the subchannel, the virtqueue number, and a cookie value, all of which fit into the registers. So this goes via the sidad as well? --Sig_/7N204=Db5u+575pzVvjR10_ Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEw9DWbcNiT/aowBjO3s9rk8bwL68FAl3NesIACgkQ3s9rk8bw L6992A//R5paNyASTYTl6I+duLvHrUaIGbDYOWp7fkUDxgSrF5yYNi4CxEgRmcOV 4fGfXW7pv5j3w9nUTPWEFBraTw/ROJLVoZZJ2Y4yS2Ssg7NBJI2L6Z1V1FqHencc rEoV6isH/ZunVP4ulrJsmXwheQilH988Flok3etzZWhuglLUzmjSTDIknjmH//iX 0jv4JI/Hvwa61DXstSvGaaosGt57VpFPb0VQtA9gre8nj4s985Eydbh1qulSABjn wVI54UG0VoMr4waTbPHXRMDDlKgjUQ/6snw4SYZnUQEzucaRfExJKAB4AOzivaO5 Q/HdxQXdJxqwTPXtGv/nXNu4zndYe7go0K0oLrNpAAN8RQGvk9kZk+RrkKJQvvhE F2rU4894FZoFbbmvpQe7bNGzcICyt2dBMqVrk5V5JDAhk9/DkMKJ7wFH7/EpWRPv OpvIF/YrEdWYaWOpgZwpT3905jF45u+2+KN/apcA7SH+tU0C0C3saNcJtzSGN4fw thJObx6aa+V6txBUgLwWPjFo+AscyxDTlzu+IMv9PSk5dNeKFw4R0MTK0hLnwl8o 8kypQfjKh6/WNAx7xc9fM/oZEnv7Gy0bpVKLdVrZxaOerPjaRuMt4PgzeRQFTlBw N087qidV+XBOeJGbJhaa00XTG3YmqofdO3/6yQVlUH21bhmrKcw= =F00O -----END PGP SIGNATURE----- --Sig_/7N204=Db5u+575pzVvjR10_--