From 86f6c224c97911b4392cb7b402e6a4ed323a449e Mon Sep 17 00:00:00 2001 From: Si-Wei Liu Date: Sat, 21 Oct 2023 02:25:19 -0700 Subject: vdpa_sim: implement .reset_map support 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 Message-Id: <1697880319-4937-8-git-send-email-si-wei.liu@oracle.com> Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang --- drivers/vdpa/vdpa_sim/vdpa_sim.c | 52 +++++++++++++++++++++++++++++++++------- 1 file changed, 43 insertions(+), 9 deletions(-) (limited to 'drivers/vdpa/vdpa_sim') 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 = NULL; } -static void vdpasim_do_reset(struct vdpasim *vdpasim) +static void vdpasim_do_reset(struct vdpasim *vdpasim, u32 flags) { int i; @@ -151,11 +151,13 @@ static void vdpasim_do_reset(struct vdpasim *vdpasim) &vdpasim->iommu_lock); } - for (i = 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] = true; + if (flags & VDPA_RESET_F_CLEAN_MAP) { + for (i = 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] = true; + } } vdpasim->running = true; @@ -259,8 +261,12 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr, if (!vdpasim->iommu_pt) goto err_iommu; - for (i = 0; i < vdpasim->dev_attr.nas; i++) + for (i = 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] = true; + } for (i = 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 *vdpa, u8 status) mutex_unlock(&vdpasim->mutex); } -static int vdpasim_reset(struct vdpa_device *vdpa) +static int vdpasim_compat_reset(struct vdpa_device *vdpa, u32 flags) { struct vdpasim *vdpasim = vdpa_to_sim(vdpa); mutex_lock(&vdpasim->mutex); vdpasim->status = 0; - vdpasim_do_reset(vdpasim); + vdpasim_do_reset(vdpasim, flags); mutex_unlock(&vdpasim->mutex); return 0; } +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 = vdpa_to_sim(vdpa); @@ -637,6 +648,25 @@ err: return ret; } +static int vdpasim_reset_map(struct vdpa_device *vdpa, unsigned int asid) +{ + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); + + if (asid >= 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] = 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 = vdpa_to_sim(vdpa); @@ -749,6 +779,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = { .get_status = vdpasim_get_status, .set_status = vdpasim_set_status, .reset = vdpasim_reset, + .compat_reset = vdpasim_compat_reset, .suspend = vdpasim_suspend, .resume = vdpasim_resume, .get_config_size = vdpasim_get_config_size, @@ -759,6 +790,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = { .set_group_asid = vdpasim_set_group_asid, .dma_map = vdpasim_dma_map, .dma_unmap = vdpasim_dma_unmap, + .reset_map = vdpasim_reset_map, .bind_mm = vdpasim_bind_mm, .unbind_mm = vdpasim_unbind_mm, .free = vdpasim_free, @@ -787,6 +819,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = { .get_status = vdpasim_get_status, .set_status = vdpasim_set_status, .reset = vdpasim_reset, + .compat_reset = vdpasim_compat_reset, .suspend = vdpasim_suspend, .resume = vdpasim_resume, .get_config_size = vdpasim_get_config_size, @@ -796,6 +829,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = { .get_iova_range = vdpasim_get_iova_range, .set_group_asid = vdpasim_set_group_asid, .set_map = vdpasim_set_map, + .reset_map = vdpasim_reset_map, .bind_mm = vdpasim_bind_mm, .unbind_mm = vdpasim_unbind_mm, .free = vdpasim_free, -- cgit v1.2.3