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 9AF95EB64D9 for ; Fri, 7 Jul 2023 08:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231616AbjGGInd (ORCPT ); Fri, 7 Jul 2023 04:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229642AbjGGInc (ORCPT ); Fri, 7 Jul 2023 04:43:32 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EABCBF5 for ; Fri, 7 Jul 2023 01:43:31 -0700 (PDT) Received: from pps.filterd (m0353728.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3678dMOj020310; Fri, 7 Jul 2023 08:43:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : reply-to : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=F+nMelXtWH0QuLZZqfIic7T5LDe1tQRdK5LmBmr8xe0=; b=XXb8ScKb/tJUnCw3dDUNCwMe8XpUwa6nDJV1a9LrkB5nIBi7LvYWBFiNTRD0ANk3/A3P tq+BNIxV0rD32fS5G1d1isFPOoKgKNdlFl0C0ggM4QCtuT4FI2AHFRqfK6Q128fAt4yg WEoktWaSqbhuemV6TwmoL8gHYhjiFkKfzLRjTkzk+UqnrpgjufjnZyqnL5g3KIpZP14g ET6mOY+bC0WLNxI07pw9fa+7meus+EvTBCST3PTgTd/v/J2mINizMMJuhFnmAO3FLOqG 4qu0v0HdBcT5vKOzHpLp00xLnM083YJ6gRKNPGYXSkorqV7TzZzqiIpsLYPUNdiCrDpf hg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3rpf2a8ee2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Jul 2023 08:43:03 +0000 Received: from m0353728.ppops.net (m0353728.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3678f5nd025883; Fri, 7 Jul 2023 08:43:03 GMT Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3rpf2a8eck-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Jul 2023 08:43:03 +0000 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3677w31h024382; Fri, 7 Jul 2023 08:43:00 GMT Received: from smtprelay06.fra02v.mail.ibm.com ([9.218.2.230]) by ppma06fra.de.ibm.com (PPS) with ESMTPS id 3rjbddtuv2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Jul 2023 08:43:00 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay06.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3678gwB827263440 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 7 Jul 2023 08:42:58 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4C63520043; Fri, 7 Jul 2023 08:42:58 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A8E1F2004B; Fri, 7 Jul 2023 08:42:55 +0000 (GMT) Received: from [9.43.6.151] (unknown [9.43.6.151]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Fri, 7 Jul 2023 08:42:55 +0000 (GMT) Message-ID: Date: Fri, 7 Jul 2023 14:12:54 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH v5 3/3] ppc: Enable 2nd DAWR support on p10 Content-Language: en-US To: David Gibson Cc: qemu-ppc@nongnu.org, mikey@neuling.org, kvm@vger.kernel.org, mst@redhat.com, mpe@ellerman.id.au, cohuck@redhat.com, qemu-devel@nongnu.org, groug@kaod.org, paulus@samba.org, clg@kaod.org, pbonzini@redhat.com, ravi.bangoria@amd.com References: <20210412114433.129702-1-ravi.bangoria@linux.ibm.com> <20210412114433.129702-4-ravi.bangoria@linux.ibm.com> From: Shivaprasad G Bhat Reply-To: YJIyCnVYohsdKLvf@yekko.fra02v.mail.ibm.com In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: GH0cxobMMVQVYaXnGAqgR_Uu3zFDWWzt X-Proofpoint-ORIG-GUID: qKGIMe0_oXr0HA773PwGY1RG_epAtZTm X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-07-07_05,2023-07-06_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 mlxscore=0 mlxlogscore=699 spamscore=0 malwarescore=0 adultscore=0 lowpriorityscore=0 impostorscore=0 suspectscore=0 phishscore=0 clxscore=1011 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2307070078 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hi David, All, I am revisiting/reviving this patch. On 5/5/21 11:20, David Gibson wrote: > On Wed, Apr 21, 2021 at 11:50:40AM +0530, Ravi Bangoria wrote: >> Hi David, >> >> On 4/19/21 10:23 AM, David Gibson wrote: >>> On Mon, Apr 12, 2021 at 05:14:33PM +0530, Ravi Bangoria wrote: >>> > Since we have released versions with POWER10 support, but no DAWR1, in > theory we need a capability so new qemu with old machine types don't > gain guest visible features that the same machine types on older qemus > had. > > Except.. there's a loophole we might use to sidestep that. The > current POWER10 CPU modelled in qemu is a DD1 - which I strongly > suspect will never appear outside of IBM. I'm pretty sure we want to > replace that with a DD2. > > While the modelled CPU is DD1, I think it's pretty reasonable to say > our POWER10 support hasn't yet stabilized, and it would therefore be > ok to simply add DAWR1 on POWER10 unconditionally, as long as we do it > before we switch over to DD2. As POWER10 DD2 switch over has already happened, the need for new/separate capability for dawr1 still holds. So, I am keeping it as is. Posting the next version after rebase. Thanks, Shivaprasad >>> I'm wondering if we're actually just better off setting the pa feature >>> just based on the guest CPU model. TCG will be broken if you try to >>> use it, but then, it already is. AFAIK there's no inherent reason we >>> couldn't implement DAWR support in TCG, it's just never been worth the >>> trouble. >> Correct. Probably there is no practical usecase for DAWR in TCG mode. >> >> Thanks, >> Ravi >>