From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH/RFC 5/9] KVM: s390: introduce post handlers for STSI Date: Mon, 16 Mar 2015 13:22:53 +0100 Message-ID: <5506CB1D.7030509@redhat.com> References: <1426495905-17531-1-git-send-email-borntraeger@de.ibm.com> <1426495905-17531-6-git-send-email-borntraeger@de.ibm.com> <5506C4C4.3050507@redhat.com> <5506CA1B.5000605@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , Alexander Graf , Cornelia Huck , Jens Freimann , Ekaterina Tumanova To: Christian Borntraeger , KVM Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34514 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750948AbbCPMXI (ORCPT ); Mon, 16 Mar 2015 08:23:08 -0400 In-Reply-To: <5506CA1B.5000605@de.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On 16/03/2015 13:18, Christian Borntraeger wrote: > Its up to a page and the content depends on the function code, selector1 > and selector2. > See arch/s390/kernel/sysinfo.c for the details or zarchitecture principles of > opration the STSI instruction. > > > Some time ago we had patches that passed the guest name > and UUID into the kernel - then Alex Graf asked, why we cant do that in > userspace. > https://lists.nongnu.org/archive/html/qemu-devel/2014-04/msg00094.html > > Now, stsi also gives the bare information as provides by upper > layers: e.g. 2.2.2 gives basic LPAR information. When doing that under > KVM or z/VM, KVM or z/VM will pass that information along to the underlying > LPAR hypervisor and give the result back to the guest. > > So I came up with the idea to let KVM do what it needs but also allow > QEMU to override (3.2.2 - this 2nd level hypervisor) If it's up to a page it definitely makes sense to do it this way. Thanks, Paolo