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 AE24CC63797 for ; Mon, 6 Feb 2023 17:38:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229957AbjBFRix (ORCPT ); Mon, 6 Feb 2023 12:38:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229571AbjBFRit (ORCPT ); Mon, 6 Feb 2023 12:38:49 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC7E2193E5; Mon, 6 Feb 2023 09:38:47 -0800 (PST) Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 316FPhIV029217; Mon, 6 Feb 2023 17:38:31 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=UyTBehJhGYTfTiCAHUGhkAFh1RJhUqMb5u/ze6LLsT8=; b=liVSF+i/JpGsqLdWVIaUNmoxX8og+EjEI/Q1nOX3GlMKBqfxGbPC6Rs6hruU3jUy2DNZ jAdskr6iUd2MrHnBM+amLCaXRhXx/bsqteEq46pIabd9ZSxc1q/CWEM9HjscH6xVDyqy ika6iKWGkpHA5W10mDfXsSgOoT8/3AugAPP+qvVnEm82KvI2XkkV/6aAHwopaK/LTAAB dhv0vkTx7/3UG5OLIUXulWZFimYlfPui7J36+4Bb3XX2nqVWtF1Q3s2cx3nZ7oWYsOsg QOe8YVLbxwdWG/NGthsAzJfiTR69bb0lqh0JtmdwDSCA7pCkW66ou6a2KYqvD++q6+WD Lg== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3nhff2mak6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 06 Feb 2023 17:38:31 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 316HcUsc011723 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 6 Feb 2023 17:38:30 GMT Received: from [10.134.67.48] (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Mon, 6 Feb 2023 09:38:29 -0800 Message-ID: <873fff36-7556-95f3-19e8-d172e8b4e47d@quicinc.com> Date: Mon, 6 Feb 2023 09:38:29 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH v9 10/27] gunyah: rsc_mgr: Add VM lifecycle RPC To: Alex Elder , Srinivas Kandagatla , Bjorn Andersson , Murali Nalajala CC: Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Prakruthi Deepak Heragu , Dmitry Baryshkov , Arnd Bergmann , "Greg Kroah-Hartman" , Rob Herring , Krzysztof Kozlowski , Jonathan Corbet , Bagas Sanjaya , Catalin Marinas , Will Deacon , Marc Zyngier , Jassi Brar , Sudeep Holla , , , , , References: <20230120224627.4053418-1-quic_eberman@quicinc.com> <20230120224627.4053418-11-quic_eberman@quicinc.com> <4db1c760-10d9-3a22-106a-dda141dd5381@linaro.org> <4a584563-1fb7-22fa-5e16-e0cf5e88b76b@linaro.org> Content-Language: en-US From: Elliot Berman In-Reply-To: <4a584563-1fb7-22fa-5e16-e0cf5e88b76b@linaro.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: dCev1PMDFJFTF0gAvXXNwrKMZTuXYWCH X-Proofpoint-GUID: dCev1PMDFJFTF0gAvXXNwrKMZTuXYWCH X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.122.1 definitions=2023-02-06_07,2023-02-06_03,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 malwarescore=0 spamscore=0 impostorscore=0 priorityscore=1501 bulkscore=0 mlxlogscore=999 suspectscore=0 lowpriorityscore=0 mlxscore=0 phishscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302060153 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/6/2023 7:41 AM, Alex Elder wrote: > On 2/2/23 6:46 AM, Srinivas Kandagatla wrote: >>> +    ret = gh_rm_call(rm, message_id, &req_payload, >>> sizeof(req_payload), &resp, &resp_size); >>> +    if (!ret && resp_size) { >> >> Am struggling to understand these type of checks in success case, when >> a command is not expecting any response why are we checking for >> response here, This sounds like a bug in either RM or hypervisor. >> >> Or Is this something that happens due to some firmware behaviour? >> Could you elobrate on this. > > What I think you're talking about is error checking even when > it's very clear something "can't happen."  It's a pattern I've > seen in Qualcomm downstream code, and I believe sometimes it > is done as "best practice" to avoid warnings from security scans. > (I might be wrong about this though.) That's right reasoning. > > I think your underlying point though is that we can just assume > success means "truly successful," so there's no reason to do any > additional sanity checks.  We *assume* the hardware is doing the > correct thing (if it's not, we might as well assume it does > *nothing* right). > > So as a very general statement, I think all checks of this type > should go away (and I think Srini would agree). > I'll remove the checks.