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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 E98FEC54E8D for ; Tue, 12 May 2020 03:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C55B320733 for ; Tue, 12 May 2020 03:41:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dvQmfIU5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728864AbgELDl0 (ORCPT ); Mon, 11 May 2020 23:41:26 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:34822 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728787AbgELDlZ (ORCPT ); Mon, 11 May 2020 23:41:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589254883; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1WZWZXE1nGez71XEyOueHoIOeCX5yLfPNsW+lHVCAeg=; b=dvQmfIU5iN43c1nkWKKXfauMYytRj1EWN0/h5JEVXU1pjmimb0By/zkBuelbPb93Uz16Fq RTbdFxlG772iEomHmL5bzTYG5q0H1mzxoY9Ci3mnWo0PqJ5/JMntZL3LlObW/0XvlZTjoJ iU+0KeSitadpoVacO8CFZmX5u/wadpY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-507-0-PIybqDMpSy_6h9ah9lWg-1; Mon, 11 May 2020 23:41:19 -0400 X-MC-Unique: 0-PIybqDMpSy_6h9ah9lWg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0B3C18005B7; Tue, 12 May 2020 03:41:18 +0000 (UTC) Received: from [10.72.13.96] (ovpn-13-96.pek2.redhat.com [10.72.13.96]) by smtp.corp.redhat.com (Postfix) with ESMTP id D00F761988; Tue, 12 May 2020 03:41:11 +0000 (UTC) Subject: Re: [PATCH] ifcvf: move IRQ request/free to status change handlers To: Francesco Lavra , Zhu Lingshan , mst@redhat.com, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: lulu@redhat.com, dan.daly@intel.com, cunming.liang@intel.com References: <1589181563-38400-1-git-send-email-lingshan.zhu@intel.com> <22d9dcdb-e790-0a68-ba41-b9530b2bf9fd@redhat.com> From: Jason Wang Message-ID: <289e3487-7ecc-6b82-35d5-3037e34c8e31@redhat.com> Date: Tue, 12 May 2020 11:41:10 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020/5/11 下午6:18, Francesco Lavra wrote: > On 5/11/20 11:26 AM, Jason Wang wrote: >> >> On 2020/5/11 下午3:19, Zhu Lingshan wrote: >>> This commit move IRQ request and free operations from probe() >>> to VIRTIO status change handler to comply with VIRTIO spec. >>> >>> VIRTIO spec 1.1, section 2.1.2 Device Requirements: Device Status Field >>> The device MUST NOT consume buffers or send any used buffer >>> notifications to the driver before DRIVER_OK. >> >> >> My previous explanation might be wrong here. It depends on how you >> implement your hardware, if you hardware guarantee that no interrupt >> will be triggered before DRIVER_OK, then it's fine. >> >> And the main goal for this patch is to allocate the interrupt on demand. >> >> >>> >>> Signed-off-by: Zhu Lingshan >>> --- >>>   drivers/vdpa/ifcvf/ifcvf_main.c | 119 >>> ++++++++++++++++++++++++---------------- >>>   1 file changed, 73 insertions(+), 46 deletions(-) >>> >>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c >>> b/drivers/vdpa/ifcvf/ifcvf_main.c >>> index abf6a061..4d58bf2 100644 >>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c >>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c >>> @@ -28,6 +28,60 @@ static irqreturn_t ifcvf_intr_handler(int irq, >>> void *arg) >>>       return IRQ_HANDLED; >>>   } >>> +static void ifcvf_free_irq_vectors(void *data) >>> +{ >>> +    pci_free_irq_vectors(data); >>> +} >>> + >>> +static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues) >>> +{ >>> +    struct pci_dev *pdev = adapter->pdev; >>> +    struct ifcvf_hw *vf = &adapter->vf; >>> +    int i; >>> + >>> + >>> +    for (i = 0; i < queues; i++) >>> +        devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]); >>> + >>> +    ifcvf_free_irq_vectors(pdev); >>> +} >>> + >>> +static int ifcvf_request_irq(struct ifcvf_adapter *adapter) >>> +{ >>> +    struct pci_dev *pdev = adapter->pdev; >>> +    struct ifcvf_hw *vf = &adapter->vf; >>> +    int vector, i, ret, irq; >>> + >>> +    ret = pci_alloc_irq_vectors(pdev, IFCVF_MAX_INTR, >>> +                    IFCVF_MAX_INTR, PCI_IRQ_MSIX); >>> +    if (ret < 0) { >>> +        IFCVF_ERR(pdev, "Failed to alloc IRQ vectors\n"); >>> +        return ret; >>> +    } >>> + >>> +    for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) { >>> +        snprintf(vf->vring[i].msix_name, 256, "ifcvf[%s]-%d\n", >>> +             pci_name(pdev), i); >>> +        vector = i + IFCVF_MSI_QUEUE_OFF; >>> +        irq = pci_irq_vector(pdev, vector); >>> +        ret = devm_request_irq(&pdev->dev, irq, >>> +                       ifcvf_intr_handler, 0, >>> +                       vf->vring[i].msix_name, >>> +                       &vf->vring[i]); >>> +        if (ret) { >>> +            IFCVF_ERR(pdev, >>> +                  "Failed to request irq for vq %d\n", i); >>> +            ifcvf_free_irq(adapter, i); >> >> >> I'm not sure this unwind is correct. It looks like we should loop and >> call devm_free_irq() for virtqueue [0, i); > > That's exactly what the code does: ifcvf_free_irq() contains a (i = 0; > i < queues; i++) loop, and here the function is called with the > `queues` argument set to `i`. > Oh right. Thanks