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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,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 CEAB6C433DB for ; Wed, 13 Jan 2021 14:54:15 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 005D1235FF for ; Wed, 13 Jan 2021 14:54:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 005D1235FF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:41044 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kzhXI-0008Qi-Kz for qemu-devel@archiver.kernel.org; Wed, 13 Jan 2021 09:54:13 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:58880) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzhVY-0007Zc-Im; Wed, 13 Jan 2021 09:52:24 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:60186 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzhVW-0006v6-KT; Wed, 13 Jan 2021 09:52:24 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 10DEVqdG087779; Wed, 13 Jan 2021 09:52:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : reply-to : references : mime-version : content-type : in-reply-to; s=pp1; bh=0hXtwqYjmeFE05CKyDaZmQZWwuJupPxxDfu6SRW9yMs=; b=dNzCYCv/rOcLXuEhW6pIkp0jjk0fbaL9mFcMbyXe1MPJcVTJq+2UhqwOUq/kq70EDLGa JU7qAUF8Y1Z+HUaL8UpgFP/Ywb+PKEwz+NafFocJViGFZYFmMyxJLIv1nzhlR+MIFmoT boX19PM1I/96Xi/w+QsV7dZG8J7fwfcZRYqOkIr/ffS8yFMIcRRLTlM0mt5kjuRVer9u 7PWDY98CH+DJ+w7BtyfQdkYFJP9nAlHRc4cSCVC+fWl2STUFhCLYtDdlT2TDtZ5a8ztS FXWz8vViNCQIJAsnsvzHvPVVhP+1K8iRIJj1rM38RAlp92sB+cviG7uUFvDpuXK+yaFZ YA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 3621ypt7js-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 13 Jan 2021 09:52:14 -0500 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 10DEXAqS096368; Wed, 13 Jan 2021 09:52:14 -0500 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 3621ypt7j5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 13 Jan 2021 09:52:13 -0500 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 10DElJw3018060; Wed, 13 Jan 2021 14:52:12 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma03ams.nl.ibm.com with ESMTP id 35y447w5an-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 13 Jan 2021 14:52:12 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 10DEqAAB35389872 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 Jan 2021 14:52:10 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0FF7B52054; Wed, 13 Jan 2021 14:52:10 +0000 (GMT) Received: from in.ibm.com (unknown [9.85.105.236]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id 0464152051; Wed, 13 Jan 2021 14:52:08 +0000 (GMT) Date: Wed, 13 Jan 2021 20:22:06 +0530 From: Bharata B Rao To: Daniel Henrique Barboza Subject: Re: [RFC PATCH v0 1/1] target/ppc: Support for H_RPT_INVALIDATE hcall Message-ID: <20210113145206.GA2421313@in.ibm.com> References: <20210106085910.2200795-1-bharata@linux.ibm.com> <2fbd70fa-17a0-2776-e4ae-a4b128713921@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2fbd70fa-17a0-2776-e4ae-a4b128713921@gmail.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2021-01-13_07:2021-01-13, 2021-01-13 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 bulkscore=0 clxscore=1015 priorityscore=1501 mlxscore=0 spamscore=0 adultscore=0 impostorscore=0 malwarescore=0 suspectscore=0 mlxlogscore=999 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101130087 Received-SPF: pass client-ip=148.163.158.5; envelope-from=bharata@linux.ibm.com; helo=mx0a-001b2d01.pphosted.com X-Spam_score_int: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: bharata@linux.ibm.com Cc: paulus@ozlabs.org, qemu-ppc@nongnu.org, qemu-devel@nongnu.org, david@gibson.dropbear.id.au Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jan 12, 2021 at 10:16:30AM -0300, Daniel Henrique Barboza wrote: > > > On 1/6/21 5:59 AM, Bharata B Rao wrote: > > If KVM_CAP_RPT_INVALIDATE KVM capability is enabled, then > > > > - indicate the availability of H_RPT_INVALIDATE hcall to the guest via > > ibm,hypertas-functions property. > > - Enable the hcall > > > > Both the above are done only if the new sPAPR machine capability > > cap-rpt-invalidate is set. > > > > Note: The KVM implementation of the hcall has been posted for upstream > > review here: > > https://lore.kernel.org/linuxppc-dev/20210105090557.2150104-1-bharata@linux.ibm.com/T/#t > > > > Update to linux-headers/linux/kvm.h here is temporary, will be > > done via header updates once the kernel change is accepted upstream. > > > > Signed-off-by: Bharata B Rao > > --- > > Code LGTM. > > Reviewed-by: Daniel Henrique Barboza > > > A few questions about the logic: > > - does it work only on Power 9 like you mentioned in the error message > down below? If it's supported on Power 10 as well then we would want the > error message to read "H_RPT_INVALIDATE only supported on POWER9 and newer" > to contemplate it. Making it conditional to Power 9 was an oversight, will remove in the next iteration. > > - Does it make sense to expose "rpt-invalidate" to Libvirt? I see that the > capability is turned off by default, which may indicate that even if kernel > and QEMU support is present the user might want to not enable it. Is there > some sort of drawback/compromise when activating this cap? I have added this to take care of migration compatibility between source and target when hcall is present in target and not present in source or vice versa. I wonder if there is any other preferred method than introducing a new machine capability like cap-rpt-invalidate. Regards, Bharata.