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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 14A05C352A1 for ; Wed, 5 Feb 2020 14:42:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E066E218AC for ; Wed, 5 Feb 2020 14:42:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QZoNCucj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726950AbgBEOms (ORCPT ); Wed, 5 Feb 2020 09:42:48 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:41954 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726308AbgBEOms (ORCPT ); Wed, 5 Feb 2020 09:42:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580913767; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SjPSSuVkfj1bPqFrA3edTkwRFepWFmIr8RSbFmPzoeU=; b=QZoNCucjGhRpdISGos0Z8h2jcbFWP4E+CBxKnnJX7jF2lgsy3E9SPmSaFIWmq6h41EOOFJ VciN6Ra3oUwjY/wZbHt1JUe1GHa/u6RJOBE0O8vWhkR14BdfP+pvjJR+JXt3y7dBCZdpS3 zMnfM63gRN1l+mP30qheSvFveZEil3Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-220-zWZSeWJYMO26wEVCbxo5bg-1; Wed, 05 Feb 2020 09:42:43 -0500 X-MC-Unique: zWZSeWJYMO26wEVCbxo5bg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 56F6F800D6C; Wed, 5 Feb 2020 14:42:42 +0000 (UTC) Received: from gondolin (dhcp-192-195.str.redhat.com [10.33.192.195]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4A8171001B05; Wed, 5 Feb 2020 14:42:38 +0000 (UTC) Date: Wed, 5 Feb 2020 15:42:35 +0100 From: Cornelia Huck To: Christian Borntraeger Cc: Janosch Frank , KVM , David Hildenbrand , Thomas Huth , Ulrich Weigand , Claudio Imbrenda , Andrea Arcangeli Subject: Re: [RFCv2 26/37] KVM: s390: protvirt: disallow one_reg Message-ID: <20200205154235.13255eb3.cohuck@redhat.com> In-Reply-To: <20200203131957.383915-27-borntraeger@de.ibm.com> References: <20200203131957.383915-1-borntraeger@de.ibm.com> <20200203131957.383915-27-borntraeger@de.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, 3 Feb 2020 08:19:46 -0500 Christian Borntraeger wrote: > From: Janosch Frank > > A lot of the registers are controlled by the Ultravisor and never > visible to KVM. Some fields in the sie control block are overlayed, > like gbea. As no userspace uses the ONE_REG interface on s390 it is safe > to disable this for protected guests. Hm, QEMU seems to fall back to ONE_REG if sync regs are not available, doesn't it? So maybe it would be better to word this as "As no known userspace uses the ONE_REG interface on s390 if sync regs are available, no functionality is lost if it is disabled for protected guests." ? > > Signed-off-by: Janosch Frank > --- > arch/s390/kvm/kvm-s390.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 6e74c7afae3a..b9692d722c1e 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -4641,6 +4641,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp, > case KVM_SET_ONE_REG: > case KVM_GET_ONE_REG: { > struct kvm_one_reg reg; > + r = -EINVAL; > + if (kvm_s390_pv_is_protected(vcpu->kvm)) > + break; > r = -EFAULT; > if (copy_from_user(®, argp, sizeof(reg))) > break; Reviewed-by: Cornelia Huck