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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E3A7CCA480 for ; Fri, 24 Jun 2022 14:49:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233235AbiFXOt2 (ORCPT ); Fri, 24 Jun 2022 10:49:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233873AbiFXOtF (ORCPT ); Fri, 24 Jun 2022 10:49:05 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04EE88152F; Fri, 24 Jun 2022 07:44:36 -0700 (PDT) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25ODhpVb031953; Fri, 24 Jun 2022 14:44:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : in-reply-to : references : date : message-id : mime-version : content-type; s=pp1; bh=2pXMCIgHJV6KAGdqoqXTrc497x6cWYzX2MTlOhCHfl4=; b=thakw+/g02odGKiUDC6CL+Mg9JrkCnvzKayejAB6vNlXr0aJHBHlHgaCS9UdPfVWa1O5 pX3eG5XU7hxDB/Gx2yy1LATUvIVqXioy9y8dsDGok8Dkq1rGi6P5j2w2/Nmi8I2heIso 2++bH/7ski2J5YBNeIlX13RFZqIZFYAMaUsGSXI3GMfHXVM9rP6e/7gve50YhsjwZH9A mR/OSiPEeS8faHWWXpfb3M8CGzibS+5q+fOoDe9HDnXBidSh9RUcniwxp8GJjOAAP9BF 6FgGXn5cxdCnwShIX4nfXv19NN5F9Md/WCvufz+T31fSPYB40ynZIQ9cWWYixGd7RqVe fA== Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3gwedesm7c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 24 Jun 2022 14:44:13 +0000 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 25OELiCV009114; Fri, 24 Jun 2022 14:44:12 GMT Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by ppma03dal.us.ibm.com with ESMTP id 3gs6bajnun-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 24 Jun 2022 14:44:12 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08026.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 25OEiBP731719754 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 24 Jun 2022 14:44:11 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4C7C678063; Fri, 24 Jun 2022 14:44:11 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7870E7805E; Fri, 24 Jun 2022 14:44:10 +0000 (GMT) Received: from localhost (unknown [9.65.252.72]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTPS; Fri, 24 Jun 2022 14:44:10 +0000 (GMT) From: Fabiano Rosas To: "Jason A. Donenfeld" , linuxppc-dev@lists.ozlabs.org, LKML , Michael Ellerman Cc: "Jason A. Donenfeld" , stable@vger.kernel.org Subject: Re: [PATCH v2 2/2] powerpc/kvm: don't crash on missing rng, and use darn In-Reply-To: <20220624142322.2049826-3-Jason@zx2c4.com> References: <20220624142322.2049826-1-Jason@zx2c4.com> <20220624142322.2049826-3-Jason@zx2c4.com> Date: Fri, 24 Jun 2022 11:44:08 -0300 Message-ID: <874k0aqfyf.fsf@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: WGq4-4M6-bGPoD6pQDgTmrzJ_4o1fsug X-Proofpoint-GUID: WGq4-4M6-bGPoD6pQDgTmrzJ_4o1fsug X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-06-24_07,2022-06-23_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 adultscore=0 priorityscore=1501 mlxscore=0 malwarescore=0 phishscore=0 bulkscore=0 mlxlogscore=604 spamscore=0 suspectscore=0 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2204290000 definitions=main-2206240056 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org "Jason A. Donenfeld" writes: > On POWER8 systems that don't have ibm,power-rng available, a guest that > ignores the KVM_CAP_PPC_HWRNG flag and calls H_RANDOM anyway will > dereference a NULL pointer. And on machines with darn instead of > ibm,power-rng, H_RANDOM won't work at all. > > This patch kills two birds with one stone, by routing H_RANDOM calls to > ppc_md.get_random_seed, and doing the real mode check inside of it. > > Cc: stable@vger.kernel.org # v4.1+ > Cc: Michael Ellerman > Fixes: e928e9cb3601 ("KVM: PPC: Book3S HV: Add fast real-mode H_RANDOM implementation.") > Signed-off-by: Jason A. Donenfeld Reviewed-by: Fabiano Rosas