From patchwork Fri Jul 24 02:57:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 11681921 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 10B0C722 for ; Fri, 24 Jul 2020 02:57:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAAAF206C1 for ; Fri, 24 Jul 2020 02:57:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="pSuzO9oG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726891AbgGXC55 (ORCPT ); Thu, 23 Jul 2020 22:57:57 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:51671 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726814AbgGXC5w (ORCPT ); Thu, 23 Jul 2020 22:57:52 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 4BCYlw2nzSz9sTT; Fri, 24 Jul 2020 12:57:48 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1595559468; bh=/o46AHd29VbcsNq9WcZf6nE94CsdYc+R5nZVL/Rr/HI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pSuzO9oG4N0zQaZIvbeJU7FN70QP4ZKEEpvcOr/jb4KRvrGtL4GgERFkyKACeAnXN C3V2s+HwQakiko3lp4TBXkrCi7CoBZhihn8CuBdR0/9T1ELAjFSeGV7tcu2j5wPuxC 6hX7tzTwsR/GqgVUfC1xdRMGLpbwYxSnB6k/qEEE= From: David Gibson To: dgilbert@redhat.com, frankja@linux.ibm.com, pair@us.ibm.com, qemu-devel@nongnu.org, pbonzini@redhat.com, brijesh.singh@amd.com Cc: ehabkost@redhat.com, marcel.apfelbaum@gmail.com, "Michael S. Tsirkin" , qemu-ppc@nongnu.org, kvm@vger.kernel.org, pasic@linux.ibm.com, qemu-s390x@nongnu.org, David Gibson , David Hildenbrand , Christian Borntraeger , Richard Henderson , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , mdroth@linux.vnet.ibm.com, Thomas Huth , Cornelia Huck Subject: [for-5.2 v4 10/10] s390: Recognize host-trust-limitation option Date: Fri, 24 Jul 2020 12:57:44 +1000 Message-Id: <20200724025744.69644-11-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200724025744.69644-1-david@gibson.dropbear.id.au> References: <20200724025744.69644-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org At least some s390 cpu models support "Protected Virtualization" (PV), a mechanism to protect guests from eavesdropping by a compromised hypervisor. This is similar in function to other mechanisms like AMD's SEV and POWER's PEF, which are controlled bythe "host-trust-limitation" machine option. s390 is a slightly special case, because we already supported PV, simply by using a CPU model with the required feature (S390_FEAT_UNPACK). To integrate this with the option used by other platforms, we implement the following compromise: - When the host-trust-limitation option is set, s390 will recognize it, verify that the CPU can support PV (failing if not) and set virtio default options necessary for encrypted or protected guests, as on other platforms. i.e. if host-trust-limitation is set, we will either create a guest capable of entering PV mode, or fail outright - If host-trust-limitation is not set, guest's might still be able to enter PV mode, if the CPU has the right model. This may be a little surprising, but shouldn't actually be harmful. To start a guest supporting Protected Virtualization using the new option use the command line arguments: -object s390-pv-guest,id=pv0 -machine host-trust-limitation=pv0 Signed-off-by: David Gibson Signed-off-by: Halil Pasic --- hw/s390x/pv.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/hw/s390x/pv.c b/hw/s390x/pv.c index ab3a2482aa..4bf3b345b6 100644 --- a/hw/s390x/pv.c +++ b/hw/s390x/pv.c @@ -14,8 +14,11 @@ #include #include "cpu.h" +#include "qapi/error.h" #include "qemu/error-report.h" #include "sysemu/kvm.h" +#include "qom/object_interfaces.h" +#include "exec/host-trust-limitation.h" #include "hw/s390x/ipl.h" #include "hw/s390x/pv.h" @@ -111,3 +114,61 @@ void s390_pv_inject_reset_error(CPUState *cs) /* Report that we are unable to enter protected mode */ env->regs[r1 + 1] = DIAG_308_RC_INVAL_FOR_PV; } + +#define TYPE_S390_PV_GUEST "s390-pv-guest" +#define S390_PV_GUEST(obj) \ + OBJECT_CHECK(S390PVGuestState, (obj), TYPE_S390_PV_GUEST) + +typedef struct S390PVGuestState S390PVGuestState; + +/** + * S390PVGuestState: + * + * The S390PVGuestState object is basically a dummy used to tell the + * host trust limitation system to use s390's PV mechanism. guest. + * + * # $QEMU \ + * -object s390-pv-guest,id=pv0 \ + * -machine ...,host-trust-limitation=pv0 + */ +struct S390PVGuestState { + Object parent_obj; +}; + +static int s390_pv_kvm_init(HostTrustLimitation *gmpo, Error **errp) +{ + if (!s390_has_feat(S390_FEAT_UNPACK)) { + error_setg(errp, + "CPU model does not support Protected Virtualization"); + return -1; + } + + return 0; +} + +static void s390_pv_guest_class_init(ObjectClass *oc, void *data) +{ + HostTrustLimitationClass *gmpc = HOST_TRUST_LIMITATION_CLASS(oc); + + gmpc->kvm_init = s390_pv_kvm_init; +} + +static const TypeInfo s390_pv_guest_info = { + .parent = TYPE_OBJECT, + .name = TYPE_S390_PV_GUEST, + .instance_size = sizeof(S390PVGuestState), + .class_init = s390_pv_guest_class_init, + .interfaces = (InterfaceInfo[]) { + { TYPE_HOST_TRUST_LIMITATION }, + { TYPE_USER_CREATABLE }, + { } + } +}; + +static void +s390_pv_register_types(void) +{ + type_register_static(&s390_pv_guest_info); +} + +type_init(s390_pv_register_types);