From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] kvm-s390: userspace access to guest storage keys Date: Mon, 09 May 2011 14:20:35 +0300 Message-ID: <4DC7CE03.1070008@redhat.com> References: <4DC3CC83.4080405@de.ibm.com> <4DC7A918.6050807@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Carsten Otte , KVM list , Christian Borntraeger , Martin Schwidefsky , Jens Freimann To: Alexander Graf Return-path: Received: from mx1.redhat.com ([209.132.183.28]:10533 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752205Ab1EILUp (ORCPT ); Mon, 9 May 2011 07:20:45 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 05/09/2011 01:11 PM, Alexander Graf wrote: > > > > And not in main memory, either? > > Nope - storage keys are only accessible using special instructions. They're not in RAM (visible to a guest) :). > Interesting, so where are they kept? An on-chip memory? That would limit the amount of main memory to that indexed by the chip. Extra off-chip memory? Asking purely out of interest, this has no bearing on the patch. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.