From nobody Wed Dec 17 04:37:11 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 EFB10C25B6B for ; Thu, 26 Oct 2023 07:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344361AbjJZHRj (ORCPT ); Thu, 26 Oct 2023 03:17:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344159AbjJZHRd (ORCPT ); Thu, 26 Oct 2023 03:17:33 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15179129 for ; Thu, 26 Oct 2023 00:17:32 -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 39Q3FQZP004619; Thu, 26 Oct 2023 07:17:27 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=9BXLcHlC+mpIFJm+VhDktZctOK6MnG2fZvm6HmvyjLg=; b=Rs3lqwAo8Be3B4aEEFM9rMNfoKIV486hCTweqP6nrCkz4e8FgmE/a7lr26SNqfDobjY/ W8YOmplnAw/v4QXV+57QrxcVaWv6+mYyUx+8oB404zKvoTCh3NIdG10QhaR2pQjHTJIy Hof4uaWs1gT19s/TZ7PfRyUo2co+HNr7LKxgW8Iam+PVGlcDbwau5BYSc6uCON64BPF8 SUZfUF3JddMeGbzDt0QYBsoaz5GJZnKwwyJrumsthWZYyfV890sq2DKFXpxNqTzRpS6S jQeVcc00ZGvS1jEqwzLVsfQcbKvNmGWtOiw3f2Ke0bnR1iXUN0xds/CgDc+O0d7+wW8U cQ== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tv5e3a9uw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Oct 2023 07:17:27 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAF015200; Thu, 26 Oct 2023 07:17:26 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-2; Thu, 26 Oct 2023 07:17:26 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 1/7] vdpa: introduce .reset_map operation callback Date: Thu, 26 Oct 2023 00:14:34 -0700 Message-Id: <1698304480-18463-2-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-GUID: iH73BH5elrVY7zO4KmEbsp8tRo1wmiLL X-Proofpoint-ORIG-GUID: iH73BH5elrVY7zO4KmEbsp8tRo1wmiLL Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some device specific IOMMU parent drivers have long standing bogus behavior that mistakenly clean up the maps during .reset. By definition, this is violation to the on-chip IOMMU ops (i.e. .set_map, or .dma_map & .dma_unmap) in those offending drivers, as the removal of internal maps is completely agnostic to the upper layer, causing inconsistent view between the userspace and the kernel. Some userspace app like QEMU gets around of this brokenness by proactively removing and adding back all the maps around vdpa device reset, but such workaround actually penalize other well-behaved driver setup, where vdpa reset always comes with the associated mapping cost, especially for kernel vDPA devices (use_va=3Dfalse) that have high cost on pinning. It's imperative to rectify this behavior and remove the problematic code from all those non-compliant parent drivers. 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 detail 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 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 device may work with DMA ops directly by implement their own to manipulate system memory mappings, so don't have to use .reset_map to achieve a simple IOMMU device model for 1:1 passthrough mapping. 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 Wed Dec 17 04:37:11 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 E1998C25B70 for ; Thu, 26 Oct 2023 07:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344410AbjJZHRm (ORCPT ); Thu, 26 Oct 2023 03:17:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229518AbjJZHRf (ORCPT ); Thu, 26 Oct 2023 03:17:35 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71298129 for ; Thu, 26 Oct 2023 00:17:33 -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 39Q3IwDq026220; Thu, 26 Oct 2023 07:17:28 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=XMke14vYG8UhRAuK8/FbiZ7AEIT4nF/4fIUeZ85zpTE=; b=Xa7jnPMrl+wrKfOMrQoVQyn9TCLQsA/mT++ti49h5mvKvibcatJgSbr3TY67ee8gR0CT P3qc6+Eam036bKuprn7oHovMjGeFqLuOjaRV+BrixkZSxVBH2yBqQk716Ezm9N+Luu97 0DvzISsJZS+AMEfqyfO+okqMPBcQmUy4puSlmcJTIln4xIUZ8OW6jYTQLla5Ap/yw2VH uRPaCR5IpPoIHuLTWwX57X0UO5uDfB621UH1Nr/86o4AFjAsYdyhXUPdFEiCUcaYee5x fMGNWl6tBVuW1SjgChcdvT+fjFZQlM+e0D0dfRmtOcr/AfF5Q9esnzvzyKN62ol5HWm9 wQ== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tv52e2bvx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Oct 2023 07:17:28 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAG015200; Thu, 26 Oct 2023 07:17:27 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-3; Thu, 26 Oct 2023 07:17:27 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 2/7] vhost-vdpa: reset vendor specific mapping to initial state in .release Date: Thu, 26 Oct 2023 00:14:35 -0700 Message-Id: <1698304480-18463-3-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-ORIG-GUID: fzDfqj1sz6XISLEWFKDdIR-3bLDD2bz7 X-Proofpoint-GUID: fzDfqj1sz6XISLEWFKDdIR-3bLDD2bz7 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 not work with DMA ops and maintain a simple IOMMU model with .reset_map. In particular, device reset should not cause mapping to go away on such IOTLB model, so persistent mapping is implied across reset. Before the userspace process using vhost-vdpa is gone, give it 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 | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 851535f57b95..c6bfe9bdde42 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 +149,14 @@ 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 cannot be + * cleaned up in the all range unmap call above. Give them + * a chance to clean up or reset the map to the desired + * state. + */ + vhost_vdpa_reset_map(v, asid); kfree(as); =20 return 0; --=20 2.39.3 From nobody Wed Dec 17 04:37:11 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 1957FC25B48 for ; Thu, 26 Oct 2023 07:17:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344322AbjJZHRs (ORCPT ); Thu, 26 Oct 2023 03:17:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230478AbjJZHRg (ORCPT ); Thu, 26 Oct 2023 03:17:36 -0400 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4458E18D for ; Thu, 26 Oct 2023 00:17:34 -0700 (PDT) Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q4AI4s026233; Thu, 26 Oct 2023 07:17:29 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=9k2d/53CGD70zPcIiDbCkVndsu3gKKkDw/PStLhE0u4=; b=APLFxUnmOrelaS9ysC8XnbAioRzcNiv1psfx5r9Lyr5u9hVIErjHc6Ik9Ha6YqsComEG tiCm+TpoxV6KxsZlBN8PjsFY0eTCFRNJ7Q+xw4d+ocS3jyjiZZ0haRxF/s3ZaPgpGSkP hh3NJfXj7Jd4QRrvYJymwzWW121PrPGGwbHkgx3oSV+3BGfDl0m6UNwYW6oPU3ZNmo6L yJifVSzYwh5fndavK6Sf8CaV+RjPBjF+j9bd35rfoDURNHcz2/ggGfKe0YUrYX+dK1oY 2iUJJalyvP+A03DXaF+0pb7DKy1LtzdkvS3wn6UNAMro0GmlMXA8eppLQc/4Qeqh6n72 MA== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tv76uaaqp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Oct 2023 07:17:29 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAI015200; Thu, 26 Oct 2023 07:17:29 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-4; Thu, 26 Oct 2023 07:17:28 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 3/7] vhost-vdpa: introduce IOTLB_PERSIST backend feature bit Date: Thu, 26 Oct 2023 00:14:36 -0700 Message-Id: <1698304480-18463-4-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-GUID: XAkapsrx_IZ8HuZxS0pHMfK541Vslfz2 X-Proofpoint-ORIG-GUID: XAkapsrx_IZ8HuZxS0pHMfK541Vslfz2 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 c6bfe9bdde42..acc7c74ba7d6 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -439,6 +439,15 @@ 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; @@ -726,6 +735,7 @@ 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))) @@ -742,6 +752,9 @@ 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; } @@ -797,6 +810,8 @@ 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 Wed Dec 17 04:37:11 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 CD446C25B48 for ; Thu, 26 Oct 2023 07:17:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344435AbjJZHRp (ORCPT ); Thu, 26 Oct 2023 03:17:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344229AbjJZHRg (ORCPT ); Thu, 26 Oct 2023 03:17:36 -0400 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 050F118F for ; Thu, 26 Oct 2023 00:17:35 -0700 (PDT) Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q3lOxJ006422; Thu, 26 Oct 2023 07:17:31 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; s=corp-2023-03-30; bh=rQlggAy4pN3gnMyAshWWZTOLkhIWgVAQ+BfTTFPvYKY=; b=daRW5WBTqGlQmcgY331Z9u0A5CNfagRyBb7fBhI8U7B6p5Jsfa9pCxGlSeZJGyLbR5IG UA/GFeGriJA82tgPblW3DUbEeh77GHsmp6dL8srAhNUgWZqtSux0WgP/BzwT8llilTRQ 59UkcD7Ja5WVP9Z597dnBzrFIwDmdtmOUAYNAs8Uf1F1yRFyGQov3Jnx6HM1h6d18Fc6 D+g9IQQGkjLOrmY7DYdN1Pjv33zC/95mP94f2rjY/bbt7k+4NVpNsdbmwoz8ElbPNI/j 1xc/V3Zry+yHstjSSlvfqAsrEpNeskZyaIwh2p4TtwBXqPUJdl9nFcXwHvMq4wOhRHGu 6Q== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tv581tau1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Oct 2023 07:17:30 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAJ015200; Thu, 26 Oct 2023 07:17:30 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-5; Thu, 26 Oct 2023 07:17:30 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 4/7] vdpa: introduce .compat_reset operation callback Date: Thu, 26 Oct 2023 00:14:37 -0700 Message-Id: <1698304480-18463-5-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> 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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-GUID: 6_9-eNJDoV-zs31ISSPnoNnTXGyRyCcj X-Proofpoint-ORIG-GUID: 6_9-eNJDoV-zs31ISSPnoNnTXGyRyCcj Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Some device specific IOMMU parent drivers have long standing bogus behaviour that mistakenly clean up the maps during .reset. By definition, this is violation to the on-chip IOMMU ops (i.e. .set_map, or .dma_map & .dma_unmap) in those offending drivers, as the removal of internal maps is completely agnostic to the upper layer, causing inconsistent view between the userspace and the kernel. Some userspace app like QEMU gets around of this brokenness by proactively removing and adding back all the maps around vdpa device reset, but such workaround actually penaltize other well-behaved driver setup, where vdpa reset always comes with the associated mapping cost, especially for kernel vDPA devices (use_va=3Dfalse) that have high cost on pinning. It's imperative to rectify this behaviour and remove the problematic code from all those non-compliant parent drivers. However, we cannot unconditionally remove the bogus map-cleaning code from the buggy .reset implementation, as there might exist userspace apps that already rely on the behaviour on some setup. Introduce a .compat_reset driver op to keep compatibility with older userspace. New and well behaved parent driver should not bother to implement such op, but only those drivers that are doing or used to do non-compliant map-cleaning reset will have to. Signed-off-by: Si-Wei Liu --- include/linux/vdpa.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index 26ae6ae1eac3..6b8cbf75712d 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -252,6 +252,17 @@ struct vdpa_map_file { * @reset: Reset device * @vdev: vdpa device * Returns integer: success (0) or error (< 0) + * @compat_reset: Reset device with compatibility quirks to + * accommodate older userspace. Only needed by + * parent driver which used to have bogus reset + * behaviour, and has to maintain such behaviour + * for compatibility with older userspace. + * Historically compliant driver only has to + * implement .reset, Historically non-compliant + * driver should implement both. + * @vdev: vdpa device + * @flags: compatibility quirks for reset + * Returns integer: success (0) or error (< 0) * @suspend: Suspend the device (optional) * @vdev: vdpa device * Returns integer: success (0) or error (< 0) @@ -393,6 +404,8 @@ struct vdpa_config_ops { u8 (*get_status)(struct vdpa_device *vdev); void (*set_status)(struct vdpa_device *vdev, u8 status); int (*reset)(struct vdpa_device *vdev); + int (*compat_reset)(struct vdpa_device *vdev, u32 flags); +#define VDPA_RESET_F_CLEAN_MAP 1 int (*suspend)(struct vdpa_device *vdev); int (*resume)(struct vdpa_device *vdev); size_t (*get_config_size)(struct vdpa_device *vdev); --=20 2.39.3 From nobody Wed Dec 17 04:37:11 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 E1131C25B6B for ; Thu, 26 Oct 2023 07:17:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344485AbjJZHRv (ORCPT ); Thu, 26 Oct 2023 03:17:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344370AbjJZHRj (ORCPT ); Thu, 26 Oct 2023 03:17:39 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B0E9129 for ; Thu, 26 Oct 2023 00:17:37 -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 39Q3mvbF004657; Thu, 26 Oct 2023 07:17:32 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; s=corp-2023-03-30; bh=iL+GGI9lnqphQGpGgu+EO6uIkX+l48HLl5Adt3nu9dI=; b=a+36HKk20oSIoM9/1HIRu8lWJPCsRjni/9LbxBkI6jQ4scvh9Bmiv0sXq5sgoKrd3VZF LP/Cdwx+pnSWA69yaeyfWJ9KACFRfhd/1FVUubeXz+RJVYW1XwL23aJ1ib7Ljcm4cefE JPhLr3yGST/eneUWHmXSzVqnIL4ZzSsGZqcsqoLxqIwMHM+yh5bprvVdHLM2016CXSkI MoZb8AWFMeOZcK3K7osgwvcvHeqPucVRv5+KMeoonfMH+nmGcuxfJvxuNB+Qk/KcVNTT FZIiF7se1Yu1AsqucXmLH6YprnGXjbgSs5BNenZ5qKqobGJCMFZkfb9Z/HeGH4rdZvtl mA== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tv5e3a9v7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 26 Oct 2023 07:17:32 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAK015200; Thu, 26 Oct 2023 07:17:31 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-6; Thu, 26 Oct 2023 07:17:31 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 5/7] vhost-vdpa: clean iotlb map during reset for older userspace Date: Thu, 26 Oct 2023 00:14:38 -0700 Message-Id: <1698304480-18463-6-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> 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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=966 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-GUID: TdFbP2b_FDK7GJTHhaF0eCwLPiYKBicx X-Proofpoint-ORIG-GUID: TdFbP2b_FDK7GJTHhaF0eCwLPiYKBicx Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Using .compat_reset op from the previous patch, the buggy .reset behaviour can be kept as-is on older userspace apps, which don't ack the IOTLB_PERSIST backend feature. As this compatibility quirk is limited to those drivers that used to be buggy in the past, it won't affect change the behaviour or affect ABI on the setups with API compliant driver. The separation of .compat_reset from the regular .reset allows vhost-vdpa able to know which driver had broken behaviour before, so it can apply the corresponding compatibility quirk to the individual driver whenever needed. Compared to overloading the existing .reset with flags, .compat_reset won't cause any extra burden to the implementation of every compliant driver. Signed-off-by: Si-Wei Liu Tested-by: Dragos Tatulea Tested-by: Lei Yang --- drivers/vhost/vdpa.c | 20 ++++++++++++++++---- drivers/virtio/virtio_vdpa.c | 2 +- include/linux/vdpa.h | 7 +++++-- 3 files changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index acc7c74ba7d6..30df5c58db73 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -227,13 +227,24 @@ static void vhost_vdpa_unsetup_vq_irq(struct vhost_vd= pa *v, u16 qid) irq_bypass_unregister_producer(&vq->call_ctx.producer); } =20 -static int vhost_vdpa_reset(struct vhost_vdpa *v) +static int _compat_vdpa_reset(struct vhost_vdpa *v) { struct vdpa_device *vdpa =3D v->vdpa; + u32 flags =3D 0; =20 - v->in_batch =3D 0; + if (v->vdev.vqs) { + flags |=3D !vhost_backend_has_feature(v->vdev.vqs[0], + VHOST_BACKEND_F_IOTLB_PERSIST) ? + VDPA_RESET_F_CLEAN_MAP : 0; + } + + return vdpa_reset(vdpa, flags); +} =20 - return vdpa_reset(vdpa); +static int vhost_vdpa_reset(struct vhost_vdpa *v) +{ + v->in_batch =3D 0; + return _compat_vdpa_reset(v); } =20 static long vhost_vdpa_bind_mm(struct vhost_vdpa *v) @@ -312,7 +323,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v,= u8 __user *statusp) vhost_vdpa_unsetup_vq_irq(v, i); =20 if (status =3D=3D 0) { - ret =3D vdpa_reset(vdpa); + ret =3D _compat_vdpa_reset(v); if (ret) return ret; } else @@ -1344,6 +1355,7 @@ static void vhost_vdpa_cleanup(struct vhost_vdpa *v) vhost_vdpa_free_domain(v); vhost_dev_cleanup(&v->vdev); kfree(v->vdev.vqs); + v->vdev.vqs =3D NULL; } =20 static int vhost_vdpa_open(struct inode *inode, struct file *filep) diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c index 06ce6d8c2e00..8d63e5923d24 100644 --- a/drivers/virtio/virtio_vdpa.c +++ b/drivers/virtio/virtio_vdpa.c @@ -100,7 +100,7 @@ static void virtio_vdpa_reset(struct virtio_device *vde= v) { struct vdpa_device *vdpa =3D vd_get_vdpa(vdev); =20 - vdpa_reset(vdpa); + vdpa_reset(vdpa, 0); } =20 static bool virtio_vdpa_notify(struct virtqueue *vq) diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index 6b8cbf75712d..db15ac07f8a6 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -519,14 +519,17 @@ static inline struct device *vdpa_get_dma_dev(struct = vdpa_device *vdev) return vdev->dma_dev; } =20 -static inline int vdpa_reset(struct vdpa_device *vdev) +static inline int vdpa_reset(struct vdpa_device *vdev, u32 flags) { const struct vdpa_config_ops *ops =3D vdev->config; int ret; =20 down_write(&vdev->cf_lock); vdev->features_valid =3D false; - ret =3D ops->reset(vdev); + if (ops->compat_reset && flags) + ret =3D ops->compat_reset(vdev, flags); + else + ret =3D ops->reset(vdev); up_write(&vdev->cf_lock); return ret; } --=20 2.39.3 From nobody Wed Dec 17 04:37:11 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 22D99C25B6B for ; Thu, 26 Oct 2023 07:17:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344495AbjJZHRy (ORCPT ); Thu, 26 Oct 2023 03:17:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344159AbjJZHRk (ORCPT ); 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Thu, 26 Oct 2023 07:17:33 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAL015200; Thu, 26 Oct 2023 07:17:32 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-7; Thu, 26 Oct 2023 07:17:32 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 6/7] vdpa/mlx5: implement .reset_map driver op Date: Thu, 26 Oct 2023 00:14:39 -0700 Message-Id: <1698304480-18463-7-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> 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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-ORIG-GUID: BHJUXJLEQ3LETPBUsG9ZNfDyrohSFrXd X-Proofpoint-GUID: BHJUXJLEQ3LETPBUsG9ZNfDyrohSFrXd Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 (including cvq mapping) on the given ASID and recreate the initial DMA mapping. That way, the device .reset op runs free from having to maintain and clean up memory mappings by itself. Additionally, implement .compat_reset to cater for older userspace, which may wish to see mapping to be cleared during reset. Co-developed-by: Dragos Tatulea Signed-off-by: Dragos Tatulea Signed-off-by: Si-Wei Liu --- drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 + drivers/vdpa/mlx5/core/mr.c | 17 +++++++++++++++++ drivers/vdpa/mlx5/net/mlx5_vnet.c | 27 ++++++++++++++++++++++++--- 3 files changed, 42 insertions(+), 3 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 f4516a2d5bb0..12ac3397f39b 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2876,7 +2876,7 @@ static void init_group_to_asid_map(struct mlx5_vdpa_d= ev *mvdev) mvdev->group2asid[i] =3D 0; } =20 -static int mlx5_vdpa_reset(struct vdpa_device *vdev) +static int mlx5_vdpa_compat_reset(struct vdpa_device *vdev, u32 flags) { struct mlx5_vdpa_dev *mvdev =3D to_mvdev(vdev); struct mlx5_vdpa_net *ndev =3D to_mlx5_vdpa_ndev(mvdev); @@ -2888,7 +2888,8 @@ 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); + if (flags & VDPA_RESET_F_CLEAN_MAP) + mlx5_vdpa_destroy_mr_resources(&ndev->mvdev); ndev->mvdev.status =3D 0; ndev->mvdev.suspended =3D false; ndev->cur_num_vqs =3D 0; @@ -2899,7 +2900,8 @@ 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 ((flags & VDPA_RESET_F_CLEAN_MAP) && + MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) { if (mlx5_vdpa_create_dma_mr(mvdev)) mlx5_vdpa_warn(mvdev, "create MR failed\n"); } @@ -2908,6 +2910,11 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) return 0; } =20 +static int mlx5_vdpa_reset(struct vdpa_device *vdev) +{ + return mlx5_vdpa_compat_reset(vdev, 0); +} + static size_t mlx5_vdpa_get_config_size(struct vdpa_device *vdev) { return sizeof(struct virtio_net_config); @@ -2987,6 +2994,18 @@ 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); @@ -3250,11 +3269,13 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = =3D { .get_status =3D mlx5_vdpa_get_status, .set_status =3D mlx5_vdpa_set_status, .reset =3D mlx5_vdpa_reset, + .compat_reset =3D mlx5_vdpa_compat_reset, .get_config_size =3D mlx5_vdpa_get_config_size, .get_config =3D mlx5_vdpa_get_config, .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 From nobody Wed Dec 17 04:37:11 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 6331FC25B48 for ; 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Thu, 26 Oct 2023 07:17:34 +0000 Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39Q6tbAM015200; Thu, 26 Oct 2023 07:17:34 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3tv537t53r-8; Thu, 26 Oct 2023 07:17:33 +0000 From: Si-Wei Liu To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, sgarzare@redhat.com, dtatulea@nvidia.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 7/7] vdpa_sim: implement .reset_map support Date: Thu, 26 Oct 2023 00:14:40 -0700 Message-Id: <1698304480-18463-8-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> References: <1698304480-18463-1-git-send-email-si-wei.liu@oracle.com> 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=2023-10-26_04,2023-10-25_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2310170001 definitions=main-2310260060 X-Proofpoint-GUID: ns7Xgnqd1tnkq0TphvnSZV7OgdBphbST X-Proofpoint-ORIG-GUID: ns7Xgnqd1tnkq0TphvnSZV7OgdBphbST Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" In order to reduce excessive memory mapping cost in live migration and VM reboot, it is desirable to decouple the vhost-vdpa IOTLB abstraction from the virtio device life cycle, i.e. mappings can be kept intact across virtio device reset. Leverage the .reset_map callback, which is meant to destroy the iotlb on the given ASID and recreate the 1:1 passthrough/identity mapping. To be consistent, the mapping on device creation is initiailized to passthrough/identity with PA 1:1 mapped as IOVA. With this the device .reset op doesn't have to maintain and clean up memory mappings by itself. Additionally, implement .compat_reset to cater for older userspace, which may wish to see mapping to be cleared during reset. Signed-off-by: Si-Wei Liu Tested-by: Stefano Garzarella --- drivers/vdpa/vdpa_sim/vdpa_sim.c | 52 ++++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 9 deletions(-) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_= sim.c index 76d41058add9..be2925d0d283 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -139,7 +139,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim, vq->vring.notify =3D NULL; } =20 -static void vdpasim_do_reset(struct vdpasim *vdpasim) +static void vdpasim_do_reset(struct vdpasim *vdpasim, u32 flags) { int i; =20 @@ -151,11 +151,13 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim) &vdpasim->iommu_lock); } =20 - for (i =3D 0; i < vdpasim->dev_attr.nas; i++) { - vhost_iotlb_reset(&vdpasim->iommu[i]); - vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX, - 0, VHOST_MAP_RW); - vdpasim->iommu_pt[i] =3D true; + if (flags & VDPA_RESET_F_CLEAN_MAP) { + for (i =3D 0; i < vdpasim->dev_attr.nas; i++) { + vhost_iotlb_reset(&vdpasim->iommu[i]); + vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX, + 0, VHOST_MAP_RW); + vdpasim->iommu_pt[i] =3D true; + } } =20 vdpasim->running =3D true; @@ -259,8 +261,12 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr= *dev_attr, if (!vdpasim->iommu_pt) goto err_iommu; =20 - for (i =3D 0; i < vdpasim->dev_attr.nas; i++) + for (i =3D 0; i < vdpasim->dev_attr.nas; i++) { vhost_iotlb_init(&vdpasim->iommu[i], max_iotlb_entries, 0); + vhost_iotlb_add_range(&vdpasim->iommu[i], 0, ULONG_MAX, 0, + VHOST_MAP_RW); + vdpasim->iommu_pt[i] =3D true; + } =20 for (i =3D 0; i < dev_attr->nvqs; i++) vringh_set_iotlb(&vdpasim->vqs[i].vring, &vdpasim->iommu[0], @@ -480,18 +486,23 @@ static void vdpasim_set_status(struct vdpa_device *vd= pa, u8 status) mutex_unlock(&vdpasim->mutex); } =20 -static int vdpasim_reset(struct vdpa_device *vdpa) +static int vdpasim_compat_reset(struct vdpa_device *vdpa, u32 flags) { struct vdpasim *vdpasim =3D vdpa_to_sim(vdpa); =20 mutex_lock(&vdpasim->mutex); vdpasim->status =3D 0; - vdpasim_do_reset(vdpasim); + vdpasim_do_reset(vdpasim, flags); mutex_unlock(&vdpasim->mutex); =20 return 0; } =20 +static int vdpasim_reset(struct vdpa_device *vdpa) +{ + return vdpasim_compat_reset(vdpa, 0); +} + static int vdpasim_suspend(struct vdpa_device *vdpa) { struct vdpasim *vdpasim =3D vdpa_to_sim(vdpa); @@ -637,6 +648,25 @@ static int vdpasim_set_map(struct vdpa_device *vdpa, u= nsigned int asid, return ret; } =20 +static int vdpasim_reset_map(struct vdpa_device *vdpa, unsigned int asid) +{ + struct vdpasim *vdpasim =3D vdpa_to_sim(vdpa); + + if (asid >=3D vdpasim->dev_attr.nas) + return -EINVAL; + + spin_lock(&vdpasim->iommu_lock); + if (vdpasim->iommu_pt[asid]) + goto out; + vhost_iotlb_reset(&vdpasim->iommu[asid]); + vhost_iotlb_add_range(&vdpasim->iommu[asid], 0, ULONG_MAX, + 0, VHOST_MAP_RW); + vdpasim->iommu_pt[asid] =3D true; +out: + spin_unlock(&vdpasim->iommu_lock); + return 0; +} + static int vdpasim_bind_mm(struct vdpa_device *vdpa, struct mm_struct *mm) { struct vdpasim *vdpasim =3D vdpa_to_sim(vdpa); @@ -749,6 +779,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = =3D { .get_status =3D vdpasim_get_status, .set_status =3D vdpasim_set_status, .reset =3D vdpasim_reset, + .compat_reset =3D vdpasim_compat_reset, .suspend =3D vdpasim_suspend, .resume =3D vdpasim_resume, .get_config_size =3D vdpasim_get_config_size, @@ -759,6 +790,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = =3D { .set_group_asid =3D vdpasim_set_group_asid, .dma_map =3D vdpasim_dma_map, .dma_unmap =3D vdpasim_dma_unmap, + .reset_map =3D vdpasim_reset_map, .bind_mm =3D vdpasim_bind_mm, .unbind_mm =3D vdpasim_unbind_mm, .free =3D vdpasim_free, @@ -787,6 +819,7 @@ static const struct vdpa_config_ops vdpasim_batch_confi= g_ops =3D { .get_status =3D vdpasim_get_status, .set_status =3D vdpasim_set_status, .reset =3D vdpasim_reset, + .compat_reset =3D vdpasim_compat_reset, .suspend =3D vdpasim_suspend, .resume =3D vdpasim_resume, .get_config_size =3D vdpasim_get_config_size, @@ -796,6 +829,7 @@ static const struct vdpa_config_ops vdpasim_batch_confi= g_ops =3D { .get_iova_range =3D vdpasim_get_iova_range, .set_group_asid =3D vdpasim_set_group_asid, .set_map =3D vdpasim_set_map, + .reset_map =3D vdpasim_reset_map, .bind_mm =3D vdpasim_bind_mm, .unbind_mm =3D vdpasim_unbind_mm, .free =3D vdpasim_free, --=20 2.39.3