From patchwork Wed Nov 3 08:16:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Longpeng(Mike)" X-Patchwork-Id: 12600341 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5F2BC433F5 for ; Wed, 3 Nov 2021 08:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B83FF60F5A for ; Wed, 3 Nov 2021 08:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231775AbhKCITx (ORCPT ); Wed, 3 Nov 2021 04:19:53 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:14709 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231512AbhKCITr (ORCPT ); Wed, 3 Nov 2021 04:19:47 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4HkfhR5F61zZcXL; Wed, 3 Nov 2021 16:15:03 +0800 (CST) Received: from dggpeml100016.china.huawei.com (7.185.36.216) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Wed, 3 Nov 2021 16:17:08 +0800 Received: from DESKTOP-27KDQMV.china.huawei.com (10.174.148.223) by dggpeml100016.china.huawei.com (7.185.36.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Wed, 3 Nov 2021 16:17:08 +0800 From: "Longpeng(Mike)" To: , CC: , , , "Longpeng(Mike)" Subject: [PATCH v5 5/6] Revert "vfio: Avoid disabling and enabling vectors repeatedly in VFIO migration" Date: Wed, 3 Nov 2021 16:16:56 +0800 Message-ID: <20211103081657.1945-6-longpeng2@huawei.com> X-Mailer: git-send-email 2.25.0.windows.1 In-Reply-To: <20211103081657.1945-1-longpeng2@huawei.com> References: <20211103081657.1945-1-longpeng2@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.148.223] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml100016.china.huawei.com (7.185.36.216) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Commit ecebe53fe993 ("vfio: Avoid disabling and enabling vectors repeatedly in VFIO migration") avoids inefficiently disabling and enabling vectors repeatedly and lets the unmasked vectors be enabled one by one. But we want to batch multiple routes and defer the commit, and only commit once outside the loop of setting vector notifiers, so we cannot enable the vectors one by one in the loop now. Revert that commit and we will take another way in the next patch, it can not only avoid disabling/enabling vectors repeatedly, but also satisfy our requirement of defer to commit. Signed-off-by: Longpeng(Mike) --- hw/vfio/pci.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 1ff84e6..69ad081 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -569,9 +569,6 @@ 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); @@ -590,22 +587,11 @@ 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. */ - if (!pdev->msix_function_masked) { - 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); + vfio_msix_vector_do_use(&vdev->pdev, 0, NULL, NULL); + vfio_msix_vector_release(&vdev->pdev, 0); - if (msix_set_vector_notifiers(pdev, vfio_msix_vector_use, + if (msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use, vfio_msix_vector_release, NULL)) { error_report("vfio: msix_set_vector_notifiers failed"); }