From nobody Thu Jan 1 22:04:37 2026 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 455FFCDB47E for ; Thu, 19 Oct 2023 01:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232421AbjJSBN0 (ORCPT ); Wed, 18 Oct 2023 21:13:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232304AbjJSBNN (ORCPT ); Wed, 18 Oct 2023 21:13:13 -0400 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0491187 for ; Wed, 18 Oct 2023 18:13:07 -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 39IIp6GW018161; Thu, 19 Oct 2023 01:13:01 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=yqGkLUNZfGgGhNcNWbKwVR1zZTQ3CSwQRCGc1fCis9U=; b=k/BctANu2LWe8QIrsW808QpPS/5fAaWTY9cgPOYJnwKMA+Zn2fGb1VE9LRcGM8KTHBoG Qc/pcbi41iN3th0PY0sHMMFRA/r6EG3FrJbJ4suphem9FUHpiYXOX7b5CDqsemSz8PcV PWq7bjbNV2wr9wWDEKlzNCmUfDc8VVc/nS9BRMDqB/5C4KLzB047vN2C+qIr2WPQ/1fQ pQGGIouQu3zX/YMwPAmFNtDsiHpIVFbpizPhVgMlB+BLor9RfLtvPumT/L1pcCHA6Ucd JpWjce27vlMv9sZh7ZNm+Uc167KQ7brzahNtWWHhwg0aVUP3dqA0cZKRf4NCzhl8gnbs bg== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3tqkhu95n2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 19 Oct 2023 01:13:01 +0000 Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 39J0UpS4015251; Thu, 19 Oct 2023 01:13:00 GMT Received: from ban25x6uut24.us.oracle.com (ban25x6uut24.us.oracle.com [10.153.73.24]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3trg1h8w2d-6; Thu, 19 Oct 2023 01:12:59 +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 v3 5/5] vdpa_sim: implement .reset_map support Date: Wed, 18 Oct 2023 18:10:18 -0700 Message-Id: <1697677818-11371-6-git-send-email-si-wei.liu@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1697677818-11371-1-git-send-email-si-wei.liu@oracle.com> References: <1697677818-11371-1-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=2023-10-19_01,2023-10-18_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 phishscore=0 suspectscore=0 mlxscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310190007 X-Proofpoint-GUID: NRw35eenR4tsRlNH_2X-m5JRqgZD1vFm X-Proofpoint-ORIG-GUID: NRw35eenR4tsRlNH_2X-m5JRqgZD1vFm 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. Add a module paramemter, iotlb_persist, 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 | 58 ++++++++++++++++++++++++++------ 1 file changed, 47 insertions(+), 11 deletions(-) diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_= sim.c index 76d41058add9..74506636375f 100644 --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -40,6 +40,10 @@ static bool use_va =3D true; module_param(use_va, bool, 0444); MODULE_PARM_DESC(use_va, "Enable/disable the device's ability to use VA"); =20 +static bool iotlb_persist =3D true; +module_param(iotlb_persist, bool, 0444); +MODULE_PARM_DESC(iotlb_persist, "Enable/disable persistent iotlb across re= set: 1 to keep maps, 0 to clear"); + #define VDPASIM_QUEUE_ALIGN PAGE_SIZE #define VDPASIM_QUEUE_MAX 256 #define VDPASIM_VENDOR_ID 0 @@ -151,11 +155,13 @@ 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 (unlikely(!iotlb_persist)) { + 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; @@ -166,8 +172,8 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim) ++vdpasim->generation; } =20 -static const struct vdpa_config_ops vdpasim_config_ops; -static const struct vdpa_config_ops vdpasim_batch_config_ops; +static struct vdpa_config_ops vdpasim_config_ops; +static struct vdpa_config_ops vdpasim_batch_config_ops; =20 static void vdpasim_work_fn(struct kthread_work *work) { @@ -191,7 +197,7 @@ static void vdpasim_work_fn(struct kthread_work *work) struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, const struct vdpa_dev_set_config *config) { - const struct vdpa_config_ops *ops; + struct vdpa_config_ops *ops; struct vdpa_device *vdpa; struct vdpasim *vdpasim; struct device *dev; @@ -213,6 +219,9 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr = *dev_attr, else ops =3D &vdpasim_config_ops; =20 + if (unlikely(!iotlb_persist)) + ops->reset_map =3D NULL; + vdpa =3D __vdpa_alloc_device(NULL, ops, dev_attr->ngroups, dev_attr->nas, dev_attr->alloc_size, @@ -259,8 +268,14 @@ 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); + if (likely(iotlb_persist)) { + 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], @@ -637,6 +652,25 @@ 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); @@ -726,7 +760,7 @@ static void vdpasim_free(struct vdpa_device *vdpa) kfree(vdpasim->config); } =20 -static const struct vdpa_config_ops vdpasim_config_ops =3D { +static struct vdpa_config_ops vdpasim_config_ops =3D { .set_vq_address =3D vdpasim_set_vq_address, .set_vq_num =3D vdpasim_set_vq_num, .kick_vq =3D vdpasim_kick_vq, @@ -759,12 +793,13 @@ static const struct vdpa_config_ops vdpasim_config_op= s =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, }; =20 -static const struct vdpa_config_ops vdpasim_batch_config_ops =3D { +static struct vdpa_config_ops vdpasim_batch_config_ops =3D { .set_vq_address =3D vdpasim_set_vq_address, .set_vq_num =3D vdpasim_set_vq_num, .kick_vq =3D vdpasim_kick_vq, @@ -796,6 +831,7 @@ 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