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 1C872C05027 for ; Thu, 9 Feb 2023 10:40:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229515AbjBIKkz (ORCPT ); Thu, 9 Feb 2023 05:40:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbjBIKkw (ORCPT ); Thu, 9 Feb 2023 05:40:52 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B8651B303; Thu, 9 Feb 2023 02:40:39 -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 319AdRaS027930; Thu, 9 Feb 2023 10:40:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=date : from : to : cc : subject : message-id : reply-to : references : mime-version : content-type : in-reply-to; s=qcppdkim1; bh=6t5H1NBBwfJ8HcZ4Okmv8djxDGNqAbuq+Tstxx356Gw=; b=pfW6x1wyQzJVXIxR1b3dM+GU/QsQsjbfg8VrYYsQ7sLQplmQ7KESWSXeX4WvD45Ddc7E G0MQEeAi37hGNQ+9l2S969vqtkOtZBFCTd4dJOxks3LbZk6/mHJZzxnKs7fvaQPSogbF GaPZzXprmJiF3drcE31DUdgOXxgEy3sVQT63uRhEuAbN+4Eet53QvS12BEjp0AqImRu8 gfK4tf9SRyqefGT3Y4mlP/1A423pjZ8D5NOTVFax7vVQFzNw1LbYVdwub/UkPKXba5il w2o9DOMVyQg4OER4kcwRtnDVrX4FVDkHHAeqLwVH6rM5+ODZTZpuFYhPG0SPCublbyZ3 zQ== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3nm8x1ub5h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 09 Feb 2023 10:40:08 +0000 Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 319Ae7lB026875 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 9 Feb 2023 10:40:07 GMT Received: from quicinc.com (10.80.80.8) by nalasex01b.na.qualcomm.com (10.47.209.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Thu, 9 Feb 2023 02:39:59 -0800 Date: Thu, 9 Feb 2023 16:09:55 +0530 From: Srivatsa Vaddagiri To: Elliot Berman CC: Bjorn Andersson , Alex Elder , Murali Nalajala , "Jonathan Corbet" , Catalin Marinas , "Will Deacon" , Trilok Soni , "Carl van Schaik" , Prakruthi Deepak Heragu , Dmitry Baryshkov , Arnd Bergmann , Greg Kroah-Hartman , Rob Herring , "Krzysztof Kozlowski" , Bagas Sanjaya , Marc Zyngier , Jassi Brar , Sudeep Holla , , , , , Subject: Re: [PATCH v9 24/27] virt: gunyah: Add proxy-scheduled vCPUs Message-ID: <20230209103955.GJ332@quicinc.com> Reply-To: Srivatsa Vaddagiri References: <20230120224627.4053418-1-quic_eberman@quicinc.com> <20230120224627.4053418-25-quic_eberman@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: <20230120224627.4053418-25-quic_eberman@quicinc.com> X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01b.na.qualcomm.com (10.47.209.197) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: gFfwHQ0MUSkxHXqstvqoV2olKdGb1RHa X-Proofpoint-ORIG-GUID: gFfwHQ0MUSkxHXqstvqoV2olKdGb1RHa 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=2023-02-09_08,2023-02-08_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 bulkscore=0 mlxscore=0 suspectscore=0 malwarescore=0 mlxlogscore=970 lowpriorityscore=0 spamscore=0 impostorscore=0 adultscore=0 priorityscore=1501 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302090101 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Elliot Berman [2023-01-20 14:46:23]: > +static void gh_handle_mmio_return(struct gunyah_vcpu *vcpu, u64 *state) > +{ > + if (!vcpu->vcpu_run->mmio.is_write) > + memcpy(&state[0], vcpu->vcpu_run->mmio.data, vcpu->vcpu_run->mmio.len); Would be good to do a bound check on length of memcpy I think (in case vcpu_run_resp->state_data[1] is wrong for example). > + > + vcpu->handle_mmio = false; > + vcpu->vcpu_run->exit_reason = GH_VM_EXIT_UNKNOWN; > +} > + // snip > +static int gh_vcpu_run(struct gunyah_vcpu *vcpu) > +{ > + struct gh_hypercall_vcpu_run_resp vcpu_run_resp; > + u64 state_data[3] = { 0 }; > + int ret = 0; > + > + ret = gh_vm_ensure_started(vcpu->ghvm); > + if (ret) > + return ret; Can we move this to VM_START ioctl and avoid this check in fast path? In case VM is not started, then I think gh_hypercall_vcpu_run() will fail which can catch erroneous use of VCPU_RUN w/o a preceding VM_START. Alternately we could use a flag in vcpu struct to check for this case (similar to test for vcpu->rsc below). // snip > + case GH_VCPU_STATE_EXPECTS_WAKEUP: > + case GH_VCPU_STATE_POWERED_OFF: > + ret = wait_for_completion_interruptible(&vcpu->ready); I think we should end this wait in case immediate_exit is set as well. > +static vm_fault_t gh_vcpu_fault(struct vm_fault *vmf) > +{ > + struct gunyah_vcpu *vcpu = vmf->vma->vm_file->private_data; > + struct page *page = NULL; > + > + if (vmf->pgoff == 0) > + page = virt_to_page(vcpu->vcpu_run); > + > + get_page(page); We should avoid get_page in case page is NULL. > + vmf->page = page; > + return 0; > +} > + > +static void gunyah_vcpu_unpopulate(struct gunyah_vm_resource_ticket *ticket, > + struct gunyah_resource *ghrsc) > +{ > + struct gunyah_vcpu *vcpu = container_of(ticket, struct gunyah_vcpu, ticket); > + > + vcpu->vcpu_run->immediate_exit = true; We should poke the vcpu thread as well so that it can notice this. Otherwise it can continue to be in gh_hypercall_vcpu_run() or wait_for_completion_interruptible() for longer time to come. > + mutex_lock(&vcpu->run_lock); > + free_irq(vcpu->rsc->irq, vcpu); > + vcpu->rsc = NULL; > + mutex_unlock(&vcpu->run_lock); > +} > + > +static long gunyah_vcpu_bind(struct gunyah_vm_function *f) > +{ > + struct gunyah_vcpu *vcpu; > + char name[MAX_VCPU_NAME]; > + struct file *file; > + struct page *page; > + int fd; > + long r; > + > + if (!gh_api_has_feature(GH_API_FEATURE_VCPU)) We should test for this feature before registering the function? What's the point in registering a function otherwise if it can't do its work!