On 2021/1/19 下午12:59, Xie Yongji wrote:
Add an opaque pointer for vhost IOTLB to store the
corresponding vma->vm_file and offset on the DMA mapping.
Let's split the patch into two.
1) opaque pointer
2) vma stuffs
It will be used in VDUSE case later.
Suggested-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
---
drivers/vdpa/vdpa_sim/vdpa_sim.c | 11 ++++---
drivers/vhost/iotlb.c | 5 ++-
drivers/vhost/vdpa.c | 66 +++++++++++++++++++++++++++++++++++-----
drivers/vhost/vhost.c | 4 +--
include/linux/vdpa.h | 3 +-
include/linux/vhost_iotlb.h | 8 ++++-
6 files changed, 79 insertions(+), 18 deletions(-)
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 03c796873a6b..1ffcef67954f 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -279,7 +279,7 @@ static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
*/
spin_lock(&vdpasim->iommu_lock);
ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
- pa, dir_to_perm(dir));
+ pa, dir_to_perm(dir), NULL);
Maybe its better to introduce
vhost_iotlb_add_range_ctx() which can accepts the opaque (context). And
let vhost_iotlb_add_range() just call that.
spin_unlock(&vdpasim->iommu_lock);
if (ret)
return DMA_MAPPING_ERROR;
@@ -317,7 +317,7 @@ static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
ret = vhost_iotlb_add_range(iommu, (u64)pa,
(u64)pa + size - 1,
- pa, VHOST_MAP_RW);
+ pa, VHOST_MAP_RW, NULL);
if (ret) {
*dma_addr = DMA_MAPPING_ERROR;
kfree(addr);
@@ -625,7 +625,8 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
map = vhost_iotlb_itree_next(map, start, last)) {
ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
- map->last, map->addr, map->perm);
+ map->last, map->addr,
+ map->perm, NULL);
if (ret)
goto err;
}
@@ -639,14 +640,14 @@ static int vdpasim_set_map(struct vdpa_device *vdpa,
}
static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
- u64 pa, u32 perm)
+ u64 pa, u32 perm, void *opaque)
{
struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
int ret;
spin_lock(&vdpasim->iommu_lock);
ret = vhost_iotlb_add_range(vdpasim->iommu, iova, iova + size - 1, pa,
- perm);
+ perm, NULL);
spin_unlock(&vdpasim->iommu_lock);
return ret;
diff --git a/drivers/vhost/iotlb.c b/drivers/vhost/iotlb.c
index 0fd3f87e913c..3bd5bd06cdbc 100644
--- a/drivers/vhost/iotlb.c
+++ b/drivers/vhost/iotlb.c
@@ -42,13 +42,15 @@ EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);
* @last: last of IOVA range
* @addr: the address that is mapped to @start
* @perm: access permission of this range
+ * @opaque: the opaque pointer for the IOTLB mapping
*
* Returns an error last is smaller than start or memory allocation
* fails
*/
int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
u64 start, u64 last,
- u64 addr, unsigned int perm)
+ u64 addr, unsigned int perm,
+ void *opaque)
{
struct vhost_iotlb_map *map;
@@ -71,6 +73,7 @@ int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,
map->last = last;
map->addr = addr;
map->perm = perm;
+ map->opaque = opaque;
iotlb->nmaps++;
vhost_iotlb_itree_insert(map, &iotlb->root);
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 36b6950ba37f..e83e5be7cec8 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -488,6 +488,7 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
struct vhost_dev *dev = &v->vdev;
struct vdpa_device *vdpa = v->vdpa;
struct vhost_iotlb *iotlb = dev->iotlb;
+ struct vhost_iotlb_file *iotlb_file;
struct vhost_iotlb_map *map;
struct page *page;
unsigned long pfn, pinned;
@@ -504,6 +505,10 @@ static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
}
atomic64_sub(map->size >> PAGE_SHIFT,
&dev->mm->pinned_vm);
+ } else if (map->opaque) {
+ iotlb_file = (struct vhost_iotlb_file *)map->opaque;
+ fput(iotlb_file->file);
+ kfree(iotlb_file);
}
vhost_iotlb_map_free(iotlb, map);
}
@@ -540,8 +545,8 @@ 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;
@@ -549,12 +554,12 @@ static int vhost_vdpa_map(struct vhost_vdpa *v,
int r = 0;
r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
- pa, perm);
+ pa, perm, opaque);
if (r)
return r;
if (ops->dma_map) {
- r = ops->dma_map(vdpa, iova, size, pa, perm);
+ 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);
@@ -591,6 +596,51 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
}
}
+static int vhost_vdpa_sva_map(struct vhost_vdpa *v,
+ u64 iova, u64 size, u64 uaddr, u32 perm)
+{
+ u64 offset, map_size, map_iova = iova;
+ struct vhost_iotlb_file *iotlb_file;
+ struct vm_area_struct *vma;
+ int ret;
Lacking mmap_read_lock().
+
+ while (size) {
+ vma = find_vma(current->mm, uaddr);
+ if (!vma) {
+ ret = -EINVAL;
+ goto err;
+ }
+ map_size = min(size, vma->vm_end - uaddr);
+ offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
+ iotlb_file = NULL;
+ if (vma->vm_file && (vma->vm_flags & VM_SHARED)) {
I wonder if we need more strict check here. When developing vhost-vdpa,
I try hard to make sure the map can only work for user pages.
So the question is: do we need to exclude MMIO area or only allow shmem
to work here?
+ iotlb_file = kmalloc(sizeof(*iotlb_file), GFP_KERNEL);
+ if (!iotlb_file) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ iotlb_file->file = get_file(vma->vm_file);
+ iotlb_file->offset = offset;
+ }
I wonder if it's better to allocate iotlb_file and make iotlb_file->file
= NULL && iotlb_file->offset = 0. This can force a consistent code for
the vDPA parents.
Or we can simply fail the map without a file as backend.
+ ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
+ perm, iotlb_file);
+ if (ret) {
+ if (iotlb_file) {
+ fput(iotlb_file->file);
+ kfree(iotlb_file);
+ }
+ goto err;
+ }
+ size -= map_size;
+ uaddr += map_size;
+ map_iova += map_size;
+ }
+ return 0;
+err:
+ vhost_vdpa_unmap(v, iova, map_iova - iova);
+ return ret;
+}
+
static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
struct vhost_iotlb_msg *msg)
{
@@ -615,8 +665,8 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
return -EEXIST;
if (vdpa->sva)
- return vhost_vdpa_map(v, msg->iova, msg->size,
- msg->uaddr, msg->perm);
+ return vhost_vdpa_sva_map(v, msg->iova, msg->size,
+ msg->uaddr, msg->perm);
So I think it's better squash vhost_vdpa_sva_map() and related changes
into previous patch.
/* Limit the use of memory for bookkeeping */
page_list = (struct page **) __get_free_page(GFP_KERNEL);
@@ -671,7 +721,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
ret = vhost_vdpa_map(v, iova, csize,
map_pfn << PAGE_SHIFT,
- msg->perm);
+ msg->perm, NULL);
if (ret) {
/*
* Unpin the pages that are left unmapped
@@ -700,7 +750,7 @@ static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
/* Pin the rest chunk */
ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
- map_pfn << PAGE_SHIFT, msg->perm);
+ map_pfn << PAGE_SHIFT, msg->perm, NULL);
out:
if (ret) {
if (nchunks) {
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index a262e12c6dc2..120dd5b3c119 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1104,7 +1104,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
vhost_vq_meta_reset(dev);
if (vhost_iotlb_add_range(dev->iotlb, msg->iova,
msg->iova + msg->size - 1,
- msg->uaddr, msg->perm)) {
+ msg->uaddr, msg->perm, NULL)) {
ret = -ENOMEM;
break;
}
@@ -1450,7 +1450,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
region->guest_phys_addr +
region->memory_size - 1,
region->userspace_addr,
- VHOST_MAP_RW))
+ VHOST_MAP_RW, NULL))
goto err;
}
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index f86869651614..b264c627e94b 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -189,6 +189,7 @@ struct vdpa_iova_range {
* @size: size of the area
* @pa: physical address for the map
* @perm: device access permission (VHOST_MAP_XX)
+ * @opaque: the opaque pointer for the mapping
* Returns integer: success (0) or error (< 0)
* @dma_unmap: Unmap an area of IOVA (optional but
* must be implemented with dma_map)
@@ -243,7 +244,7 @@ struct vdpa_config_ops {
/* DMA ops */
int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
- u64 pa, u32 perm);
+ u64 pa, u32 perm, void *opaque);
int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);
/* Free device resources */
diff --git a/include/linux/vhost_iotlb.h b/include/linux/vhost_iotlb.h
index 6b09b786a762..66a50c11c8ca 100644
--- a/include/linux/vhost_iotlb.h
+++ b/include/linux/vhost_iotlb.h
@@ -4,6 +4,11 @@
#include <linux/interval_tree_generic.h>
+struct vhost_iotlb_file {
+ struct file *file;
+ u64 offset;
+};
I think we'd better either:
1) simply use struct vhost_iotlb_file * instead of void *opaque for
vhost_iotlb_map
or
2)rename and move the vhost_iotlb_file to vdpa
2) looks better since we want to let vhost iotlb to carry any type of
context (opaque pointer)
And if we do this, the modification of vdpa_config_ops deserves a
separate patch.
Thanks
+
struct vhost_iotlb_map {
struct rb_node rb;
struct list_head link;
@@ -17,6 +22,7 @@ struct vhost_iotlb_map {
u32 perm;
u32 flags_padding;
u64 __subtree_last;
+ void *opaque;
};
#define VHOST_IOTLB_FLAG_RETIRE 0x1
@@ -30,7 +36,7 @@ struct vhost_iotlb {
};
int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, u64 start, u64 last,
- u64 addr, unsigned int perm);
+ u64 addr, unsigned int perm, void *opaque);
void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last);
struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags);
