From nobody Mon Feb 9 12:15:19 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=huawei.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1635325638931447.88263097721926; Wed, 27 Oct 2021 02:07:18 -0700 (PDT) Received: from localhost ([::1]:38414 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mfetx-0003Zd-Rx for importer@patchew.org; Wed, 27 Oct 2021 05:07:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37100) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mferg-0001NE-9a for qemu-devel@nongnu.org; Wed, 27 Oct 2021 05:04:56 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:2887) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mferQ-00080y-UO for qemu-devel@nongnu.org; Wed, 27 Oct 2021 05:04:56 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4HfN4W36Cqz1DHtg; Wed, 27 Oct 2021 17:02:35 +0800 (CST) Received: from dggema765-chm.china.huawei.com (10.1.198.207) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.15; Wed, 27 Oct 2021 17:04:30 +0800 Received: from DESKTOP-6NKE0BC.china.huawei.com (10.174.185.210) by dggema765-chm.china.huawei.com (10.1.198.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.15; Wed, 27 Oct 2021 17:04:30 +0800 From: Kunkun Jiang To: Alex Williamson , Eric Auger , "open list:All patches CC here" Subject: [PATCH v3 1/2] vfio/pci: Add support for mmapping sub-page MMIO BARs after live migration Date: Wed, 27 Oct 2021 17:04:05 +0800 Message-ID: <20211027090406.761-2-jiangkunkun@huawei.com> X-Mailer: git-send-email 2.26.2.windows.1 In-Reply-To: <20211027090406.761-1-jiangkunkun@huawei.com> References: <20211027090406.761-1-jiangkunkun@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.185.210] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggema765-chm.china.huawei.com (10.1.198.207) X-CFilter-Loop: Reflected Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=45.249.212.255; envelope-from=jiangkunkun@huawei.com; helo=szxga08-in.huawei.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, 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: wanghaibin.wang@huawei.com, Kunkun Jiang , tangnianyao@huawei.com, ganqixin@huawei.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZM-MESSAGEID: 1635325641233100001 Content-Type: text/plain; charset="utf-8" We can expand MemoryRegions of sub-page MMIO BARs in vfio_pci_write_config() to improve IO performance for some devices. However, the MemoryRegions of destination VM are not expanded any more after live migration. Because their addresses have been updated in vmstate_load_state() (vfio_pci_load_config) and vfio_sub_page_bar_update_mapping() will not be called. This may result in poor performance after live migration. So iterate BARs in vfio_pci_load_config() and try to update sub-page BARs. Reported-by: Nianyao Tang Reported-by: Qixin Gan Signed-off-by: Kunkun Jiang --- hw/vfio/pci.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 5cdf1d4298..7b45353ce2 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2453,7 +2453,12 @@ static int vfio_pci_load_config(VFIODevice *vbasedev= , QEMUFile *f) { VFIOPCIDevice *vdev =3D container_of(vbasedev, VFIOPCIDevice, vbasedev= ); PCIDevice *pdev =3D &vdev->pdev; - int ret; + pcibus_t old_addr[PCI_NUM_REGIONS - 1]; + int bar, ret; + + for (bar =3D 0; bar < PCI_ROM_SLOT; bar++) { + old_addr[bar] =3D pdev->io_regions[bar].addr; + } =20 ret =3D vmstate_load_state(f, &vmstate_vfio_pci_config, vdev, 1); if (ret) { @@ -2463,6 +2468,18 @@ static int vfio_pci_load_config(VFIODevice *vbasedev= , QEMUFile *f) vfio_pci_write_config(pdev, PCI_COMMAND, pci_get_word(pdev->config + PCI_COMMAND), 2); =20 + for (bar =3D 0; bar < PCI_ROM_SLOT; bar++) { + /* + * The address may not be changed in some scenarios + * (e.g. the VF driver isn't loaded in VM). + */ + if (old_addr[bar] !=3D pdev->io_regions[bar].addr && + vdev->bars[bar].region.size > 0 && + vdev->bars[bar].region.size < qemu_real_host_page_size) { + vfio_sub_page_bar_update_mapping(pdev, bar); + } + } + if (msi_enabled(pdev)) { vfio_msi_enable(vdev); } else if (msix_enabled(pdev)) { --=20 2.23.0