From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E246C46470 for ; Wed, 8 Aug 2018 12:47:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 390B1219E8 for ; Wed, 8 Aug 2018 12:47:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 390B1219E8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727206AbeHHPHM (ORCPT ); Wed, 8 Aug 2018 11:07:12 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58820 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726745AbeHHPHL (ORCPT ); Wed, 8 Aug 2018 11:07:11 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8C23281663D8; Wed, 8 Aug 2018 12:47:38 +0000 (UTC) Received: from gondolin (dhcp-192-215.str.redhat.com [10.33.192.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5293F1C731; Wed, 8 Aug 2018 12:47:35 +0000 (UTC) Date: Wed, 8 Aug 2018 14:47:33 +0200 From: Cornelia Huck To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Heiko Carstens , Martin Schwidefsky , Janosch Frank , Christian Borntraeger , Pierre Morel Subject: Re: [PATCH RFC 2/2] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART Message-ID: <20180808144733.507ba955.cohuck@redhat.com> In-Reply-To: <20180807125131.3606-3-david@redhat.com> References: <20180807125131.3606-1-david@redhat.com> <20180807125131.3606-3-david@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 08 Aug 2018 12:47:38 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 08 Aug 2018 12:47:38 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'cohuck@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 7 Aug 2018 14:51:31 +0200 David Hildenbrand wrote: > When we change the crycb (or execution controls), we also have to make sure > that the vSIE shadow datastructures properly consider the changed > values before rerunning the vSIE. We can achieve that by simply using a > VCPU request now. Is this actually a concrete problem right now, or does this only become a real concern with vfio-ap? > > This has to be a synchronous request (== handled before entering the > (v)SIE again). > > The request will make sure that the vSIE handler is left, and that the > request will be processed (NOP), therefore forcing a reload of all > vSIE data (including rebuilding the crycb) when re-entering the vSIE > interception handler the next time. > > Signed-off-by: David Hildenbrand > --- > arch/s390/include/asm/kvm_host.h | 1 + > arch/s390/kvm/kvm-s390.c | 7 ++++++- > 2 files changed, 7 insertions(+), 1 deletion(-) Reviewed-by: Cornelia Huck