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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2290DC433E0 for ; Tue, 2 Mar 2021 21:34:29 +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 80B4A64F1A for ; Tue, 2 Mar 2021 21:34:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80B4A64F1A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36332 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lHCex-0004hF-5J for qemu-devel@archiver.kernel.org; Tue, 02 Mar 2021 16:34:27 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:55090) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lHCXa-00038N-OA for qemu-devel@nongnu.org; Tue, 02 Mar 2021 16:26:50 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41246) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lHCXY-00053V-2o for qemu-devel@nongnu.org; Tue, 02 Mar 2021 16:26:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614720406; 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=SN+pYTFwW0AI998xEFeXLntBCHMnJo3GWrA7byw4bEg=; b=b0sFBspro6n6gz2XBknfcv+3JhbvjyGX1vpoD/jBrAesaz/Etb8r9W2mPkltgVGvPO5bQ8 Qm+osyiH7S1M+8tXkmA0Z4zlrcQOiydiZARh7yhMhOAcF6ycP6nebwCqpxAxm6dqUtpTDi roM1x1ckAmXl3VsBQqfHvHKNlQI+8U8= 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-415-2AWfUDhjNgm-LMY-ffS8Bg-1; Tue, 02 Mar 2021 16:26:42 -0500 X-MC-Unique: 2AWfUDhjNgm-LMY-ffS8Bg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5E40585EE60; Tue, 2 Mar 2021 21:26:40 +0000 (UTC) Received: from omen.home.shazbot.org (ovpn-112-255.phx2.redhat.com [10.3.112.255]) by smtp.corp.redhat.com (Postfix) with ESMTP id 192246F7E6; Tue, 2 Mar 2021 21:26:28 +0000 (UTC) Date: Tue, 2 Mar 2021 14:26:28 -0700 From: Alex Williamson To: Shenming Lu , , marcel.apfelbaum@gmail.com Subject: Re: [PATCH v3 3/3] vfio: Avoid disabling and enabling vectors repeatedly in VFIO migration Message-ID: <20210302142628.60e0ab6f@omen.home.shazbot.org> In-Reply-To: <20210223022225.50-4-lushenming@huawei.com> References: <20210223022225.50-1-lushenming@huawei.com> <20210223022225.50-4-lushenming@huawei.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=alex.williamson@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=alex.williamson@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, 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" MST/Marcel, Do you have an Ack or objection to exporting msix_masked() as below? 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);