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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8DF78C432C3 for ; Fri, 15 Nov 2019 09:03:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65C5120733 for ; Fri, 15 Nov 2019 09:03:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="M0Aac7RW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727073AbfKOJDI (ORCPT ); Fri, 15 Nov 2019 04:03:08 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:41082 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727059AbfKOJDI (ORCPT ); Fri, 15 Nov 2019 04:03:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573808586; 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=4Ylzuw0MFzogSbNwyDr1XDn1X0CmhhzBiYdtRVmGClw=; b=M0Aac7RWuAAdtcaBSU47WcOmtpiP//TtXQa7YMTADpIk70cS085XjR6vlnykEoLhTMBtur tuLh2a0d8QM4znQ5lmTYeOpaJ7mJYAFI0pWbAn1MU1IY7S9hcVkO0LVy7aDHf/a/biC6gJ /aW+RTul3aPsNT5GW4qG2YBfVM2GMNQ= 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-244-eff2Ar84M_-bnxma5jABhg-1; Fri, 15 Nov 2019 04:03:03 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B1D1A8048E5; Fri, 15 Nov 2019 09:03:01 +0000 (UTC) Received: from localhost.localdomain (ovpn-117-14.ams2.redhat.com [10.36.117.14]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4D7D55E264; Fri, 15 Nov 2019 09:02:57 +0000 (UTC) Subject: Re: [RFC 26/37] KVM: s390: protvirt: Only sync fmt4 registers To: Janosch Frank , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, david@redhat.com, borntraeger@de.ibm.com, imbrenda@linux.ibm.com, mihajlov@linux.ibm.com, mimu@linux.ibm.com, cohuck@redhat.com, gor@linux.ibm.com References: <20191024114059.102802-1-frankja@linux.ibm.com> <20191024114059.102802-27-frankja@linux.ibm.com> From: Thomas Huth Message-ID: <197c1218-3171-3e22-caf8-47cdab58caf8@redhat.com> Date: Fri, 15 Nov 2019 10:02:55 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <20191024114059.102802-27-frankja@linux.ibm.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: eff2Ar84M_-bnxma5jABhg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 24/10/2019 13.40, Janosch Frank wrote: > A lot of the registers are controlled by the Ultravisor and never > visible to KVM. Also some registers are overlayed, like gbea is with > sidad, which might leak data to userspace. >=20 > Hence we sync a minimal set of registers for both SIE formats and then > check and sync format 2 registers if necessary. >=20 > Also we disable set/get one reg for the same reason. It's an old > interface anyway. >=20 > Signed-off-by: Janosch Frank > --- > arch/s390/kvm/kvm-s390.c | 138 +++++++++++++++++++++++---------------- > 1 file changed, 82 insertions(+), 56 deletions(-) >=20 > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c > index 17a78774c617..f623c64aeade 100644 > --- a/arch/s390/kvm/kvm-s390.c > +++ b/arch/s390/kvm/kvm-s390.c > @@ -2997,7 +2997,8 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_= vcpu *vcpu) > =09/* make sure the new fpc will be lazily loaded */ > =09save_fpu_regs(); > =09current->thread.fpu.fpc =3D 0; > -=09vcpu->arch.sie_block->gbea =3D 1; > +=09if (!kvm_s390_pv_is_protected(vcpu->kvm)) > +=09=09vcpu->arch.sie_block->gbea =3D 1; > =09vcpu->arch.sie_block->pp =3D 0; > =09vcpu->arch.sie_block->fpf &=3D ~FPF_BPBC; > =09vcpu->arch.pfault_token =3D KVM_S390_PFAULT_TOKEN_INVALID; > @@ -3367,6 +3368,10 @@ static int kvm_arch_vcpu_ioctl_get_one_reg(struct = kvm_vcpu *vcpu, > =09=09=09 (u64 __user *)reg->addr); > =09=09break; > =09case KVM_REG_S390_GBEA: > +=09=09if (kvm_s390_pv_is_protected(vcpu->kvm)) { > +=09=09=09r =3D 0; > +=09=09=09break; > +=09=09} > =09=09r =3D put_user(vcpu->arch.sie_block->gbea, > =09=09=09 (u64 __user *)reg->addr); > =09=09break; > @@ -3420,6 +3425,10 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct = kvm_vcpu *vcpu, > =09=09=09 (u64 __user *)reg->addr); > =09=09break; > =09case KVM_REG_S390_GBEA: > +=09=09if (kvm_s390_pv_is_protected(vcpu->kvm)) { > +=09=09=09r =3D 0; > +=09=09=09break; > +=09=09} Wouldn't it be better to return EINVAL in this case? ... the callers definitely do not get what they expected here... Thomas