From nobody Thu Dec 18 17:15:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 100B9CDB474 for ; Tue, 17 Oct 2023 00:42:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234233AbjJQAmt (ORCPT ); Mon, 16 Oct 2023 20:42:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232873AbjJQAmr (ORCPT ); Mon, 16 Oct 2023 20:42:47 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26D6B9B for ; Mon, 16 Oct 2023 17:42:46 -0700 (PDT) Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39GKO29L011029; Tue, 17 Oct 2023 00:42:39 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2023-03-30; bh=EDhfB7JA2J6D7sXgXuclzb2hlADtZpOfMMez4ap+xqE=; b=fyR8kgNauCTuMLIiF65GWmNQj7Or2UTtdmYu0wEumqu2er1M6ifjo35zBYk2rVBOKBvE RpwiVpjJlcmaQ4/WSvx25pIi6r9HG6R0qzOhMdxIxzwRsE0Jy/2fw+X1e6fQgsim0ejy salnmQJibZHWzKIIUrayIDC3zma/Rz3+21w4Df2yYab5A2APaWMhZh4rii70C7uvI9Mr ecZ+dINbmDgKbR7VZasYXHiK6+7GW0E9Ht/B/gjxZJ79owr60/TpuPu0s4CToo08AG7L Epg0eIj2QZS9VIlJYZ/AFzmex9q3COcDw+Ib8CK2vPk/Ix8cZxhSmWIO5S6Tdx/Rw97i Dg== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tqjync01q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Oct 2023 00:42:38 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39GNB27I027141; Tue, 17 Oct 2023 00:42:37 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3trg535bja-2; Tue, 17 Oct 2023 00:42:37 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, xuanzhuo@linux.alibaba.com, dtatulea@nvidia.com, sgarzare@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/4] vdpa: introduce .reset_map operation callback Date: Mon, 16 Oct 2023 17:39:54 -0700 Message-Id: <1697503197-15935-2-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> References: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-16_13,2023-10-12_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0 malwarescore=0 suspectscore=0 mlxlogscore=992 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310170003 X-Proofpoint-GUID: 6v4slETenWCoQQ5DyNOOwRHPhACqeQXc X-Proofpoint-ORIG-GUID: 6v4slETenWCoQQ5DyNOOwRHPhACqeQXc Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Device specific IOMMU parent driver who wishes to see mapping to be decoupled from virtio or vdpa device life cycle (device reset) can use it to restore memory mapping in the device IOMMU to the initial or default state. The reset of mapping is done per address space basis. The reason why a separate .reset_map op is introduced is because this allows a simple on-chip IOMMU model without exposing too much device implementation details to the upper vdpa layer. The .dma_map/unmap or .set_map driver API is meant to be used to manipulate the IOTLB mappings, and has been abstracted in a way similar to how a real IOMMU device maps or unmaps pages for certain memory ranges. However, apart from this there also exists other mapping needs, in which case 1:1 passthrough mapping has to be used by other users (read virtio-vdpa). To ease parent/vendor driver implementation and to avoid abusing DMA ops in an unexpacted way, these on-chip IOMMU devices can start with 1:1 passthrough mapping mode initially at the he time of creation. Then the .reset_map op can be used to switch iotlb back to this initial state without having to expose a complex two-dimensional IOMMU device model. The .reset_map is not a MUST for every parent that implements the .dma_map or .set_map API, because there could be software vDPA devices (which has use_va=3Dtrue) that don't have to pin kernel memory so they don't care much about high mapping cost during device reset. And those software devices may have also implemented their own DMA ops, so don't have to use .reset_map to achieve a simple IOMMU device model for 1:1 passthrough mapping, either. Signed-off-by: Si-Wei Liu Acked-by: Eugenio P=C3=A9rez Acked-by: Jason Wang --- include/linux/vdpa.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index d376309b99cf..26ae6ae1eac3 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -327,6 +327,15 @@ struct vdpa_map_file { * @iova: iova to be unmapped * @size: size of the area * Returns integer: success (0) or error (< 0) + * @reset_map: Reset device memory mapping to the default + * state (optional) + * Needed for devices that are using device + * specific DMA translation and prefer mapping + * to be decoupled from the virtio life cycle, + * i.e. device .reset op does not reset mapping + * @vdev: vdpa device + * @asid: address space identifier + * Returns integer: success (0) or error (< 0) * @get_vq_dma_dev: Get the dma device for a specific * virtqueue (optional) * @vdev: vdpa device @@ -405,6 +414,7 @@ struct vdpa_config_ops { u64 iova, u64 size, u64 pa, u32 perm, void *opaque); int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid, u64 iova, u64 size); + int (*reset_map)(struct vdpa_device *vdev, unsigned int asid); int (*set_group_asid)(struct vdpa_device *vdev, unsigned int group, unsigned int asid); struct device *(*get_vq_dma_dev)(struct vdpa_device *vdev, u16 idx); --=20 2.39.3 From nobody Thu Dec 18 17:15:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E354CDB465 for ; Tue, 17 Oct 2023 00:42:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234270AbjJQAmv (ORCPT ); Mon, 16 Oct 2023 20:42:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233634AbjJQAms (ORCPT ); Mon, 16 Oct 2023 20:42:48 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B51B0AB for ; Mon, 16 Oct 2023 17:42:46 -0700 (PDT) Received: from pps.filterd (m0333520.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39GKO4wl027744; Tue, 17 Oct 2023 00:42:40 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2023-03-30; bh=IDcJMsPyKM2GyU6ZB9/xv6m5PTlDgNod8sH4SwkNOK4=; b=IekHjyXEpcAYb1ceZF8zo28I0mdCseO++R85dOjDSLbZnbTsRhb4+fpjmAS4fCNykMk0 vYgKBoRiA846OIpdDKECrwawdAKrZfE3QsoBw82IMSGePiX2aF2acIZ7yozO/xnvWgNA d/pbgMTC7b1XBxMM231CJJbRcXjekXV9ZC/TcVgodYyWRIdL7bFOB4apOEBUcBUbGtYN wUaiR3q1UfzW2YHcDQrBqmQoyoQ+4HNUusaRgLL8OAU/HpCj7ZEhOTnWp681q/yZiuMZ GV5neI1FH3lntyoAyk7iKDBHGQkSaT3KAEKPgKHQMuL2eVBkTshahlRoMtuc15UQ2YBS sQ== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tqk1cc1s5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Oct 2023 00:42:39 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39GNB27J027141; Tue, 17 Oct 2023 00:42:38 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3trg535bja-3; Tue, 17 Oct 2023 00:42:38 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, xuanzhuo@linux.alibaba.com, dtatulea@nvidia.com, sgarzare@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/4] vhost-vdpa: reset vendor specific mapping to initial state in .release Date: Mon, 16 Oct 2023 17:39:55 -0700 Message-Id: <1697503197-15935-3-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> References: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-16_13,2023-10-12_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0 malwarescore=0 suspectscore=0 mlxlogscore=999 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310170003 X-Proofpoint-ORIG-GUID: 4TVzLTo0akgalRbDmG5s7ktKewo1HLu_ X-Proofpoint-GUID: 4TVzLTo0akgalRbDmG5s7ktKewo1HLu_ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Devices with on-chip IOMMU or vendor specific IOTLB implementation may need to restore iotlb mapping to the initial or default state using the .reset_map op, as it's desirable for some parent devices to solely manipulate mappings by its own, independent of virtio device state. For instance, device reset does not cause mapping go away on such IOTLB model in need of persistent mapping. Before vhost-vdpa is going away, give them a chance to reset iotlb back to the initial state in vhost_vdpa_cleanup(). Signed-off-by: Si-Wei Liu Acked-by: Eugenio P=C3=A9rez --- drivers/vhost/vdpa.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 851535f57b95..a3f8160c9807 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -131,6 +131,15 @@ static struct vhost_vdpa_as *vhost_vdpa_find_alloc_as(= struct vhost_vdpa *v, return vhost_vdpa_alloc_as(v, asid); } =20 +static void vhost_vdpa_reset_map(struct vhost_vdpa *v, u32 asid) +{ + struct vdpa_device *vdpa =3D v->vdpa; + const struct vdpa_config_ops *ops =3D vdpa->config; + + if (ops->reset_map) + ops->reset_map(vdpa, asid); +} + static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid) { struct vhost_vdpa_as *as =3D asid_to_as(v, asid); @@ -140,6 +149,13 @@ static int vhost_vdpa_remove_as(struct vhost_vdpa *v, = u32 asid) =20 hlist_del(&as->hash_link); vhost_vdpa_iotlb_unmap(v, &as->iotlb, 0ULL, 0ULL - 1, asid); + /* + * Devices with vendor specific IOMMU may need to restore + * iotlb to the initial or default state which is not done + * through device reset, as the IOTLB mapping manipulation + * could be decoupled from the virtio device life cycle. + */ + vhost_vdpa_reset_map(v, asid); kfree(as); =20 return 0; --=20 2.39.3 From nobody Thu Dec 18 17:15:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83FC2CDB465 for ; Tue, 17 Oct 2023 00:42:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234307AbjJQAm4 (ORCPT ); Mon, 16 Oct 2023 20:42:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234245AbjJQAmu (ORCPT ); Mon, 16 Oct 2023 20:42:50 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77FC09B for ; Mon, 16 Oct 2023 17:42:48 -0700 (PDT) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39GKO8bX014418; Tue, 17 Oct 2023 00:42:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2023-03-30; bh=KrpapIJ3BkNAXiuqRX7bRQLsn2/RQH2+BsvlPVXHXNA=; b=glPMvXzHavU3wJJTbXGlGb60s2ADRLv3I12Yb/1hQXGoSjh88YfThCFrU0jPLObxTdTb ZR9KV2ISQvZkCxJXcIy5NxXGbT2WGQZnX3a4ZlG7/WbLd6CqVJAYE3YsuEmTUq5zpSpN jCdDZpiTkM3S4/ry17/uCTR6xBTjkaR/IId/4NYNalFV9W8qAgplwjS7+BehB55vHFM2 QeZ2l7rJdAcvLMjRUxb+ssuDQcH7lCm39mUYluBVbO6WjoX8MuJlx5qn3XDRGZEdEbxH LAP6H8E7v07CtmMNZ+Y/y22q0hWdckxF00RiTqEs9Ogft57DkDMX+3VV4EFIgvt3L8xq Zg== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tqk1bkxsn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Oct 2023 00:42:40 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39GNB27K027141; Tue, 17 Oct 2023 00:42:39 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3trg535bja-4; Tue, 17 Oct 2023 00:42:39 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, xuanzhuo@linux.alibaba.com, dtatulea@nvidia.com, sgarzare@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/4] vhost-vdpa: introduce IOTLB_PERSIST backend feature bit Date: Mon, 16 Oct 2023 17:39:56 -0700 Message-Id: <1697503197-15935-4-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> References: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-16_13,2023-10-12_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0 malwarescore=0 suspectscore=0 mlxlogscore=999 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310170003 X-Proofpoint-GUID: Evj-k7e-lxAQDDNY1nc-XlkIMSEyxO8b X-Proofpoint-ORIG-GUID: Evj-k7e-lxAQDDNY1nc-XlkIMSEyxO8b Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Userspace needs this feature flag to distinguish if vhost-vdpa iotlb in the kernel can be trusted to persist IOTLB mapping across vDPA reset. Without it, userspace has no way to tell apart if it's running on an older kernel, which could silently drop all iotlb mapping across vDPA reset, especially with broken parent driver implementation for the .reset driver op. The broken driver may incorrectly drop all mappings of its own as part of .reset, which inadvertently ends up with corrupted mapping state between vhost-vdpa userspace and the kernel. As a workaround, to make the mapping behaviour predictable across reset, userspace has to pro-actively remove all mappings before vDPA reset, and then restore all the mappings afterwards. This workaround is done unconditionally on top of all parent drivers today, due to the parent driver implementation issue and no means to differentiate. This workaround had been utilized in QEMU since day one when the corresponding vhost-vdpa userspace backend came to the world. There are 3 cases that backend may claim this feature bit on for: - parent device that has to work with platform IOMMU - parent device with on-chip IOMMU that has the expected .reset_map support in driver - parent device with vendor specific IOMMU implementation with persistent IOTLB mapping already that has to specifically declare this backend feature The reason why .reset_map is being one of the pre-condition for persistent iotlb is because without it, vhost-vdpa can't switch back iotlb to the initial state later on, especially for the on-chip IOMMU case which starts with identity mapping at device creation. virtio-vdpa requires on-chip IOMMU to perform 1:1 passthrough translation from PA to IOVA as-is to begin with, and .reset_map is the only means to turn back iotlb to the identity mapping mode after vhost-vdpa is gone. The difference in behavior did not matter as QEMU unmaps all the memory unregistering the memory listener at vhost_vdpa_dev_start( started =3D false), but the backend acknowledging this feature flag allows QEMU to make sure it is safe to skip this unmap & map in the case of vhost stop & start cycle. In that sense, this feature flag is actually a signal for userspace to know that the driver bug has been solved. Not offering it indicates that userspace cannot trust the kernel will retain the maps. Signed-off-by: Si-Wei Liu Acked-by: Eugenio P=C3=A9rez --- drivers/vhost/vdpa.c | 15 +++++++++++++++ include/uapi/linux/vhost_types.h | 2 ++ 2 files changed, 17 insertions(+) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index a3f8160c9807..9202986a7d81 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -438,6 +438,15 @@ static u64 vhost_vdpa_get_backend_features(const struc= t vhost_vdpa *v) return ops->get_backend_features(vdpa); } =20 +static bool vhost_vdpa_has_persistent_map(const struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa =3D v->vdpa; + const struct vdpa_config_ops *ops =3D vdpa->config; + + return (!ops->set_map && !ops->dma_map) || ops->reset_map || + vhost_vdpa_get_backend_features(v) & BIT_ULL(VHOST_BACKEND_F_IOTLB= _PERSIST); +} + static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *feat= urep) { struct vdpa_device *vdpa =3D v->vdpa; @@ -725,6 +734,7 @@ static long vhost_vdpa_unlocked_ioctl(struct file *file= p, return -EFAULT; if (features & ~(VHOST_VDPA_BACKEND_FEATURES | BIT_ULL(VHOST_BACKEND_F_DESC_ASID) | + BIT_ULL(VHOST_BACKEND_F_IOTLB_PERSIST) | BIT_ULL(VHOST_BACKEND_F_SUSPEND) | BIT_ULL(VHOST_BACKEND_F_RESUME) | BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK))) @@ -741,6 +751,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *file= p, if ((features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) && !vhost_vdpa_has_desc_group(v)) return -EOPNOTSUPP; + if ((features & BIT_ULL(VHOST_BACKEND_F_IOTLB_PERSIST)) && + !vhost_vdpa_has_persistent_map(v)) + return -EOPNOTSUPP; vhost_set_backend_features(&v->vdev, features); return 0; } @@ -796,6 +809,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *file= p, features |=3D BIT_ULL(VHOST_BACKEND_F_RESUME); if (vhost_vdpa_has_desc_group(v)) features |=3D BIT_ULL(VHOST_BACKEND_F_DESC_ASID); + if (vhost_vdpa_has_persistent_map(v)) + features |=3D BIT_ULL(VHOST_BACKEND_F_IOTLB_PERSIST); features |=3D vhost_vdpa_get_backend_features(v); if (copy_to_user(featurep, &features, sizeof(features))) r =3D -EFAULT; diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_ty= pes.h index 18ad6ae7ab5c..d7656908f730 100644 --- a/include/uapi/linux/vhost_types.h +++ b/include/uapi/linux/vhost_types.h @@ -190,5 +190,7 @@ struct vhost_vdpa_iova_range { * buffers may reside. Requires VHOST_BACKEND_F_IOTLB_ASID. */ #define VHOST_BACKEND_F_DESC_ASID 0x7 +/* IOTLB don't flush memory mapping across device reset */ +#define VHOST_BACKEND_F_IOTLB_PERSIST 0x8 =20 #endif --=20 2.39.3 From nobody Thu Dec 18 17:15:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3650CDB465 for ; Tue, 17 Oct 2023 00:43:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234349AbjJQAnE (ORCPT ); Mon, 16 Oct 2023 20:43:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234261AbjJQAmu (ORCPT ); Mon, 16 Oct 2023 20:42:50 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 842EC92 for ; Mon, 16 Oct 2023 17:42:49 -0700 (PDT) Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39GKO4BI011132; Tue, 17 Oct 2023 00:42:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2023-03-30; bh=WEr4JGhEt6neFXoJwZaO0Xs8r8Ued1/sBS5Auy1yR+s=; b=tbhvgKGsUaqzEyNd9PBKXWXchCJVKq2RvEbxJvZRgB2VhRbhVDiaW+rmfJzcPoTqnYyk 4fz9RZ22UFZnnY7vIZDJNAdFOaMX7CLNky/wNnrbiqxe65Nlood4CuvmmzCQLS/vxrVX qLotEBJwDW4BArKR6p8ZQdr8fWseSXRYOd8bp3rwNzZZSswJUMKraze1ErLs31q+4e/3 /b9IBT2RpvIj5lvIGcCUTxPN9SGHU9YFRACv69hkL4/zp4dFJ8SaysoAhWUWeDSrrN7i 4dOfe8y6xbJ21zGeU8Sxtkc508O6XmBxgzheEHShTiIMrL68tPAiRhkl7ZMvpUstsQ9A Bw== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tqjync01u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Oct 2023 00:42:41 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39GNB27L027141; Tue, 17 Oct 2023 00:42:40 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3trg535bja-5; Tue, 17 Oct 2023 00:42:40 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, xuanzhuo@linux.alibaba.com, dtatulea@nvidia.com, sgarzare@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 4/4] vdpa/mlx5: implement .reset_map driver op Date: Mon, 16 Oct 2023 17:39:57 -0700 Message-Id: <1697503197-15935-5-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> References: <1697503197-15935-1-git-send-email-si-wei.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-16_13,2023-10-12_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0 malwarescore=0 suspectscore=0 mlxlogscore=999 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310170003 X-Proofpoint-GUID: -pbDF6oNQ7-PqtuDB7Ak_yjYkgTYxiAW X-Proofpoint-ORIG-GUID: -pbDF6oNQ7-PqtuDB7Ak_yjYkgTYxiAW Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit 6f5312f80183 ("vdpa/mlx5: Add support for running with virtio_vdpa"), mlx5_vdpa starts with preallocate 1:1 DMA MR at device creation time. This 1:1 DMA MR will be implicitly destroyed while the first .set_map call is invoked, in which case callers like vhost-vdpa will start to set up custom mappings. When the .reset callback is invoked, the custom mappings will be cleared and the 1:1 DMA MR will be re-created. In order to reduce excessive memory mapping cost in live migration, it is desirable to decouple the vhost-vdpa IOTLB abstraction from the virtio device life cycle, i.e. mappings can be kept around intact across virtio device reset. Leverage the .reset_map callback, which is meant to destroy the regular MR on the given ASID and recreate the initial DMA mapping. That way, the device .reset op can run free from having to maintain and clean up memory mappings by itself. The cvq mapping also needs to be cleared if is in the given ASID. Co-developed-by: Dragos Tatulea Signed-off-by: Dragos Tatulea Signed-off-by: Si-Wei Liu Acked-by: Eugenio P=C3=A9rez --- drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 + drivers/vdpa/mlx5/core/mr.c | 17 +++++++++++++++++ drivers/vdpa/mlx5/net/mlx5_vnet.c | 18 +++++++++++++----- 3 files changed, 31 insertions(+), 5 deletions(-) diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/ml= x5_vdpa.h index db988ced5a5d..84547d998bcf 100644 --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h @@ -127,6 +127,7 @@ int mlx5_vdpa_update_cvq_iotlb(struct mlx5_vdpa_dev *mv= dev, struct vhost_iotlb *iotlb, unsigned int asid); int mlx5_vdpa_create_dma_mr(struct mlx5_vdpa_dev *mvdev); +int mlx5_vdpa_reset_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid); =20 #define mlx5_vdpa_warn(__dev, format, ...) = \ dev_warn((__dev)->mdev->device, "%s:%d:(pid %d) warning: " format, __func= __, __LINE__, \ diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c index 66530e28f327..2197c46e563a 100644 --- a/drivers/vdpa/mlx5/core/mr.c +++ b/drivers/vdpa/mlx5/core/mr.c @@ -645,3 +645,20 @@ int mlx5_vdpa_create_dma_mr(struct mlx5_vdpa_dev *mvde= v) =20 return mlx5_vdpa_update_cvq_iotlb(mvdev, NULL, 0); } + +int mlx5_vdpa_reset_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid) +{ + if (asid >=3D MLX5_VDPA_NUM_AS) + return -EINVAL; + + mlx5_vdpa_destroy_mr(mvdev, mvdev->mr[asid]); + + if (asid =3D=3D 0 && MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) { + if (mlx5_vdpa_create_dma_mr(mvdev)) + mlx5_vdpa_warn(mvdev, "create DMA MR failed\n"); + } else { + mlx5_vdpa_update_cvq_iotlb(mvdev, NULL, asid); + } + + return 0; +} diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5= _vnet.c index 6abe02310f2b..928e71bc5571 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2838,7 +2838,6 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) unregister_link_notifier(ndev); teardown_driver(ndev); clear_vqs_ready(ndev); - mlx5_vdpa_destroy_mr_resources(&ndev->mvdev); ndev->mvdev.status =3D 0; ndev->mvdev.suspended =3D false; ndev->cur_num_vqs =3D 0; @@ -2849,10 +2848,6 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) init_group_to_asid_map(mvdev); ++mvdev->generation; =20 - if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) { - if (mlx5_vdpa_create_dma_mr(mvdev)) - mlx5_vdpa_warn(mvdev, "create MR failed\n"); - } up_write(&ndev->reslock); =20 return 0; @@ -2932,6 +2927,18 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vde= v, unsigned int asid, return err; } =20 +static int mlx5_vdpa_reset_map(struct vdpa_device *vdev, unsigned int asid) +{ + struct mlx5_vdpa_dev *mvdev =3D to_mvdev(vdev); + struct mlx5_vdpa_net *ndev =3D to_mlx5_vdpa_ndev(mvdev); + int err; + + down_write(&ndev->reslock); + err =3D mlx5_vdpa_reset_mr(mvdev, asid); + up_write(&ndev->reslock); + return err; +} + static struct device *mlx5_get_vq_dma_dev(struct vdpa_device *vdev, u16 id= x) { struct mlx5_vdpa_dev *mvdev =3D to_mvdev(vdev); @@ -3199,6 +3206,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops =3D= { .set_config =3D mlx5_vdpa_set_config, .get_generation =3D mlx5_vdpa_get_generation, .set_map =3D mlx5_vdpa_set_map, + .reset_map =3D mlx5_vdpa_reset_map, .set_group_asid =3D mlx5_set_group_asid, .get_vq_dma_dev =3D mlx5_get_vq_dma_dev, .free =3D mlx5_vdpa_free, --=20 2.39.3