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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E5942C433E0 for ; Tue, 9 Mar 2021 07:28:51 +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 9690165199 for ; Tue, 9 Mar 2021 07:28:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9690165199 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44608 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJWnS-0005xi-Or for qemu-devel@archiver.kernel.org; Tue, 09 Mar 2021 02:28:50 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34020) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJWlD-00048W-7R; Tue, 09 Mar 2021 02:26:32 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:3558) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJWl5-0006RQ-77; Tue, 09 Mar 2021 02:26:30 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4Dvmtg2wlgzjWbD; Tue, 9 Mar 2021 15:24:43 +0800 (CST) Received: from [10.174.184.135] (10.174.184.135) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.498.0; Tue, 9 Mar 2021 15:26:04 +0800 Subject: Re: [PATCH v3 3/3] vfio: Avoid disabling and enabling vectors repeatedly in VFIO migration To: Alex Williamson , , References: <20210223022225.50-1-lushenming@huawei.com> <20210223022225.50-4-lushenming@huawei.com> <20210302142628.60e0ab6f@omen.home.shazbot.org> From: Shenming Lu Message-ID: <97a3189a-f053-cb77-0ae9-02530fb4ac89@huawei.com> Date: Tue, 9 Mar 2021 15:25:52 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 In-Reply-To: <20210302142628.60e0ab6f@omen.home.shazbot.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.184.135] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.32; envelope-from=lushenming@huawei.com; helo=szxga06-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=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: , Cc: Lorenzo Pieralisi , Neo Jia , Marc Zyngier , Cornelia Huck , qemu-devel@nongnu.org, "Dr . David Alan Gilbert" , Eric Auger , Kirti Wankhede , qemu-arm@nongnu.org, yuzenghui@huawei.com, wanghaibin.wang@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2021/3/3 5:26, Alex Williamson wrote: > > MST/Marcel, > > Do you have an Ack or objection to exporting msix_masked() as below? Or could we use msix_function_masked instead as below? :-) if (!pdev->msix_function_masked) { for (nr = 0; nr < msix_nr_vectors_allocated(pdev); nr++) { if (!msix_is_masked(pdev, nr)) { max_vec = nr; } } } Thanks, Shenming > Thanks, > > Alex > > On Tue, 23 Feb 2021 10:22:25 +0800 > Shenming Lu wrote: > >> In VFIO migration resume phase and some guest startups, there are >> already unmasked vectors in the vector table when calling >> vfio_msix_enable(). So in order to avoid inefficiently disabling >> and enabling vectors repeatedly, let's allocate all needed vectors >> first and then enable these unmasked vectors one by one without >> disabling. >> >> Signed-off-by: Shenming Lu >> --- >> hw/pci/msix.c | 2 +- >> hw/vfio/pci.c | 20 +++++++++++++++++--- >> include/hw/pci/msix.h | 1 + >> 3 files changed, 19 insertions(+), 4 deletions(-) >> >> diff --git a/hw/pci/msix.c b/hw/pci/msix.c >> index ae9331cd0b..e057958fcd 100644 >> --- a/hw/pci/msix.c >> +++ b/hw/pci/msix.c >> @@ -131,7 +131,7 @@ static void msix_handle_mask_update(PCIDevice *dev, int vector, bool was_masked) >> } >> } >> >> -static bool msix_masked(PCIDevice *dev) >> +bool msix_masked(PCIDevice *dev) >> { >> return dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK; >> } >> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c >> index f74be78209..088fd41926 100644 >> --- a/hw/vfio/pci.c >> +++ b/hw/vfio/pci.c >> @@ -569,6 +569,9 @@ static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr) >> >> static void vfio_msix_enable(VFIOPCIDevice *vdev) >> { >> + PCIDevice *pdev = &vdev->pdev; >> + unsigned int nr, max_vec = 0; >> + >> vfio_disable_interrupts(vdev); >> >> vdev->msi_vectors = g_new0(VFIOMSIVector, vdev->msix->entries); >> @@ -587,11 +590,22 @@ static void vfio_msix_enable(VFIOPCIDevice *vdev) >> * triggering to userspace, then immediately release the vector, leaving >> * the physical device with no vectors enabled, but MSI-X enabled, just >> * like the guest view. >> + * If there are already unmasked vectors (in migration resume phase and >> + * some guest startups) which will be enabled soon, we can allocate all >> + * of them here to avoid inefficiently disabling and enabling vectors >> + * repeatedly later. >> */ >> - vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL); >> - vfio_msix_vector_release(&vdev->pdev, 0); >> + if (!msix_masked(pdev)) { >> + for (nr = 0; nr < msix_nr_vectors_allocated(pdev); nr++) { >> + if (!msix_is_masked(pdev, nr)) { >> + max_vec = nr; >> + } >> + } >> + } >> + vfio_msix_vector_do_use(pdev, max_vec, NULL, NULL); >> + vfio_msix_vector_release(pdev, max_vec); >> >> - if (msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use, >> + if (msix_set_vector_notifiers(pdev, vfio_msix_vector_use, >> vfio_msix_vector_release, NULL)) { >> error_report("vfio: msix_set_vector_notifiers failed"); >> } >> diff --git a/include/hw/pci/msix.h b/include/hw/pci/msix.h >> index 4c4a60c739..b3cd88e262 100644 >> --- a/include/hw/pci/msix.h >> +++ b/include/hw/pci/msix.h >> @@ -28,6 +28,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f); >> >> int msix_enabled(PCIDevice *dev); >> int msix_present(PCIDevice *dev); >> +bool msix_masked(PCIDevice *dev); >> >> bool msix_is_masked(PCIDevice *dev, unsigned vector); >> void msix_set_pending(PCIDevice *dev, unsigned vector); > > . >