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authorXie Yongji <xieyongji@bytedance.com>2021-08-31 13:36:31 +0300
committerMichael S. Tsirkin <mst@redhat.com>2021-09-06 14:20:57 +0300
commitd8945ec411209272bcd4ae9e75ea1b078257e492 (patch)
treeddee9fc4da7335ccdf380c4799b380207d47007f /drivers/vhost
parent22af48cf91aae5f2fd32fe811d9be1c52d7a801b (diff)
downloadlinux-d8945ec411209272bcd4ae9e75ea1b078257e492.tar.xz
vdpa: Support transferring virtual addressing during DMA mapping
This patch introduces an attribute for vDPA device to indicate whether virtual address can be used. If vDPA device driver set it, vhost-vdpa bus driver will not pin user page and transfer userspace virtual address instead of physical address during DMA mapping. And corresponding vma->vm_file and offset will be also passed as an opaque pointer. Suggested-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210831103634.33-11-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/vdpa.c99
1 files changed, 88 insertions, 11 deletions
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index ad50d52d6655..f41d081777f5 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -526,8 +526,28 @@ static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, u64 start, u64 last)
}
}
+static void vhost_vdpa_va_unmap(struct vhost_vdpa *v, u64 start, u64 last)
+{
+ struct vhost_dev *dev = &v->vdev;
+ struct vhost_iotlb *iotlb = dev->iotlb;
+ struct vhost_iotlb_map *map;
+ struct vdpa_map_file *map_file;
+
+ while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
+ map_file = (struct vdpa_map_file *)map->opaque;
+ fput(map_file->file);
+ kfree(map_file);
+ vhost_iotlb_map_free(iotlb, map);
+ }
+}
+
static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
{
+ struct vdpa_device *vdpa = v->vdpa;
+
+ if (vdpa->use_va)
+ return vhost_vdpa_va_unmap(v, start, last);
+
return vhost_vdpa_pa_unmap(v, start, last);
}
@@ -562,21 +582,21 @@ static int perm_to_iommu_flags(u32 perm)
return flags | IOMMU_CACHE;
}
-static int vhost_vdpa_map(struct vhost_vdpa *v,
- u64 iova, u64 size, u64 pa, u32 perm)
+static int vhost_vdpa_map(struct vhost_vdpa *v, u64 iova,
+ u64 size, u64 pa, u32 perm, void *opaque)
{
struct vhost_dev *dev = &v->vdev;
struct vdpa_device *vdpa = v->vdpa;
const struct vdpa_config_ops *ops = vdpa->config;
int r = 0;
- r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
- pa, perm);
+ r = vhost_iotlb_add_range_ctx(dev->iotlb, iova, iova + size - 1,
+ pa, perm, opaque);
if (r)
return r;
if (ops->dma_map) {
- r = ops->dma_map(vdpa, iova, size, pa, perm, NULL);
+ r = ops->dma_map(vdpa, iova, size, pa, perm, opaque);
} else if (ops->set_map) {
if (!v->in_batch)
r = ops->set_map(vdpa, dev->iotlb);
@@ -584,13 +604,15 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
r = iommu_map(v->domain, iova, pa, size,
perm_to_iommu_flags(perm));
}
-
- if (r)
+ if (r) {
vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
- else
+ return r;
+ }
+
+ if (!vdpa->use_va)
atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm);
- return r;
+ return 0;
}
static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
@@ -611,6 +633,56 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
}
}
+static int vhost_vdpa_va_map(struct vhost_vdpa *v,
+ u64 iova, u64 size, u64 uaddr, u32 perm)
+{
+ struct vhost_dev *dev = &v->vdev;
+ u64 offset, map_size, map_iova = iova;
+ struct vdpa_map_file *map_file;
+ struct vm_area_struct *vma;
+ int ret;
+
+ mmap_read_lock(dev->mm);
+
+ while (size) {
+ vma = find_vma(dev->mm, uaddr);
+ if (!vma) {
+ ret = -EINVAL;
+ break;
+ }
+ map_size = min(size, vma->vm_end - uaddr);
+ if (!(vma->vm_file && (vma->vm_flags & VM_SHARED) &&
+ !(vma->vm_flags & (VM_IO | VM_PFNMAP))))
+ goto next;
+
+ map_file = kzalloc(sizeof(*map_file), GFP_KERNEL);
+ if (!map_file) {
+ ret = -ENOMEM;
+ break;
+ }
+ offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
+ map_file->offset = offset;
+ map_file->file = get_file(vma->vm_file);
+ ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
+ perm, map_file);
+ if (ret) {
+ fput(map_file->file);
+ kfree(map_file);
+ break;
+ }
+next:
+ size -= map_size;
+ uaddr += map_size;
+ map_iova += map_size;
+ }
+ if (ret)
+ vhost_vdpa_unmap(v, iova, map_iova - iova);
+
+ mmap_read_unlock(dev->mm);
+
+ return ret;
+}
+
static int vhost_vdpa_pa_map(struct vhost_vdpa *v,
u64 iova, u64 size, u64 uaddr, u32 perm)
{
@@ -677,7 +749,7 @@ static int vhost_vdpa_pa_map(struct vhost_vdpa *v,
csize = PFN_PHYS(last_pfn - map_pfn + 1);
ret = vhost_vdpa_map(v, iova, csize,
PFN_PHYS(map_pfn),
- perm);
+ perm, NULL);
if (ret) {
/*
* Unpin the pages that are left unmapped
@@ -706,7 +778,7 @@ static int vhost_vdpa_pa_map(struct vhost_vdpa *v,
/* Pin the rest chunk */
ret = vhost_vdpa_map(v, iova, PFN_PHYS(last_pfn - map_pfn + 1),
- PFN_PHYS(map_pfn), perm);
+ PFN_PHYS(map_pfn), perm, NULL);
out:
if (ret) {
if (nchunks) {
@@ -739,6 +811,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
struct vhost_iotlb_msg *msg)
{
struct vhost_dev *dev = &v->vdev;
+ struct vdpa_device *vdpa = v->vdpa;
struct vhost_iotlb *iotlb = dev->iotlb;
if (msg->iova < v->range.first || !msg->size ||
@@ -750,6 +823,10 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
msg->iova + msg->size - 1))
return -EEXIST;
+ if (vdpa->use_va)
+ return vhost_vdpa_va_map(v, msg->iova, msg->size,
+ msg->uaddr, msg->perm);
+
return vhost_vdpa_pa_map(v, msg->iova, msg->size, msg->uaddr,
msg->perm);
}