On 2021/2/23 7:50 下午, Xie Yongji wrote:
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 <jasow...@redhat.com>
Signed-off-by: Xie Yongji <xieyon...@bytedance.com>
---
drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
drivers/vdpa/vdpa.c | 9 +++-
drivers/vdpa/vdpa_sim/vdpa_sim.c | 2 +-
drivers/vhost/vdpa.c | 104 +++++++++++++++++++++++++++++++-------
include/linux/vdpa.h | 20 ++++++--
6 files changed, 113 insertions(+), 26 deletions(-)
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 7c8bbfcf6c3e..228b9f920fea 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -432,7 +432,7 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct
pci_device_id *id)
adapter = vdpa_alloc_device(struct ifcvf_adapter, vdpa,
dev, &ifc_vdpa_ops,
- IFCVF_MAX_QUEUE_PAIRS * 2, NULL);
+ IFCVF_MAX_QUEUE_PAIRS * 2, NULL, false);
if (adapter == NULL) {
IFCVF_ERR(pdev, "Failed to allocate vDPA structure");
return -ENOMEM;
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 029822060017..54290438da28 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1964,7 +1964,7 @@ static int mlx5v_probe(struct auxiliary_device *adev,
max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);
ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mlx5_vdpa_ops,
- 2 * mlx5_vdpa_max_qps(max_vqs), NULL);
+ 2 * mlx5_vdpa_max_qps(max_vqs), NULL, false);
if (IS_ERR(ndev))
return PTR_ERR(ndev);
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 9700a0adcca0..fafc0ee5eb05 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -72,6 +72,7 @@ static void vdpa_release_dev(struct device *d)
* @nvqs: number of virtqueues supported by this device
* @size: size of the parent structure that contains private data
* @name: name of the vdpa device; optional.
+ * @use_va: indicate whether virtual address can be used by this device
I think "use_va" means va must be used instead of "can be" here.
*
* Driver should use vdpa_alloc_device() wrapper macro instead of
* using this directly.
@@ -81,7 +82,8 @@ static void vdpa_release_dev(struct device *d)
*/
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
- int nvqs, size_t size, const char *name)
+ int nvqs, size_t size, const char *name,
+ bool use_va)
{
struct vdpa_device *vdev;
int err = -EINVAL;
@@ -92,6 +94,10 @@ struct vdpa_device *__vdpa_alloc_device(struct device
*parent,
if (!!config->dma_map != !!config->dma_unmap)
goto err;
+ /* It should only work for the device that use on-chip IOMMU */
+ if (use_va && !(config->dma_map || config->set_map))
+ goto err;
+
err = -ENOMEM;
vdev = kzalloc(size, GFP_KERNEL);
if (!vdev)
@@ -108,6 +114,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device
*parent,
vdev->config = config;
vdev->features_valid = false;
vdev->nvqs = nvqs;
+ vdev->use_va = use_va;
if (name)
err = dev_set_name(&vdev->dev, "%s", name);
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 5cfc262ce055..3a9a2dd4e987 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -235,7 +235,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr
*dev_attr)
ops = &vdpasim_config_ops;
vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
- dev_attr->nvqs, dev_attr->name);
+ dev_attr->nvqs, dev_attr->name, false);
if (!vdpasim)
goto err_alloc;
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 70857fe3263c..93769ace34df 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -480,21 +480,31 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
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_map *map;
+ struct vdpa_map_file *map_file;
struct page *page;
unsigned long pfn, pinned;
while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
- pinned = map->size >> PAGE_SHIFT;
- for (pfn = map->addr >> PAGE_SHIFT;
- pinned > 0; pfn++, pinned--) {
- page = pfn_to_page(pfn);
- if (map->perm & VHOST_ACCESS_WO)
- set_page_dirty_lock(page);
- unpin_user_page(page);
+ if (!vdpa->use_va) {
+ pinned = map->size >> PAGE_SHIFT;
+ for (pfn = map->addr >> PAGE_SHIFT;
+ pinned > 0; pfn++, pinned--) {
+ page = pfn_to_page(pfn);
+ if (map->perm & VHOST_ACCESS_WO)
+ set_page_dirty_lock(page);
+ unpin_user_page(page);
+ }
+ atomic64_sub(map->size >> PAGE_SHIFT,
+ &dev->mm->pinned_vm);
+ } else {
+ map_file = (struct vdpa_map_file *)map->opaque;
+ if (map_file->file)
+ fput(map_file->file);
+ kfree(map_file);
}
- atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
vhost_iotlb_map_free(iotlb, map);
}
}
@@ -530,21 +540,21 @@ 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);
@@ -552,13 +562,15 @@ 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(size >> PAGE_SHIFT, &dev->mm->pinned_vm);
- return r;
+ return 0;
}
static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
@@ -579,10 +591,60 @@ 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;
+ goto err;
+ }
+ map_size = min(size, vma->vm_end - uaddr);
+ offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
+ map_file = kzalloc(sizeof(*map_file), GFP_KERNEL);
+ if (!map_file) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ if (vma->vm_file && (vma->vm_flags & VM_SHARED) &&
+ !(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
+ map_file->file = get_file(vma->vm_file);
+ map_file->offset = offset;
+ }
I think it's better to do the flag check right after find_vma(), this
can avoid things like kfree etc (e.g the code will still call
vhost_vdpa_map() even if the flag is not expected now).
+ ret = vhost_vdpa_map(v, map_iova, map_size, uaddr,
+ perm, map_file);
+ if (ret) {
+ if (map_file->file)
+ fput(map_file->file);
+ kfree(map_file);
+ goto err;
+ }
+ size -= map_size;
+ uaddr += map_size;
+ map_iova += map_size;
+ }
+ mmap_read_unlock(dev->mm);
+
+ 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)
{
struct vhost_dev *dev = &v->vdev;
+ struct vdpa_device *vdpa = v->vdpa;
struct vhost_iotlb *iotlb = dev->iotlb;
struct page **page_list;
unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
@@ -601,6 +663,10 @@ 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);
If possible, I would like to factor out the pa map below into a
something like vhost_vdpa_pa_map() first with a separated patch. Then
introduce vhost_vdpa_va_map().
Thanks
+
/* Limit the use of memory for bookkeeping */
page_list = (struct page **) __get_free_page(GFP_KERNEL);
if (!page_list)
@@ -654,7 +720,7 @@ 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
@@ -683,7 +749,7 @@ 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/include/linux/vdpa.h b/include/linux/vdpa.h
index 93dca2c328ae..bfae6d780c38 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -44,6 +44,7 @@ struct vdpa_mgmt_dev;
* @config: the configuration ops for this device.
* @index: device index
* @features_valid: were features initialized? for legacy guests
+ * @use_va: indicate whether virtual address can be used by this device
* @nvqs: maximum number of supported virtqueues
* @mdev: management device pointer; caller must setup when registering
device as part
* of dev_add() mgmtdev ops callback before invoking
_vdpa_register_device().
@@ -54,6 +55,7 @@ struct vdpa_device {
const struct vdpa_config_ops *config;
unsigned int index;
bool features_valid;
+ bool use_va;
int nvqs;
struct vdpa_mgmt_dev *mdev;
};
@@ -69,6 +71,16 @@ struct vdpa_iova_range {
};
/**
+ * Corresponding file area for device memory mapping
+ * @file: vma->vm_file for the mapping
+ * @offset: mapping offset in the vm_file
+ */
+struct vdpa_map_file {
+ struct file *file;
+ u64 offset;
+};
+
+/**
* vDPA_config_ops - operations for configuring a vDPA device.
* Note: vDPA device drivers are required to implement all of the
* operations unless it is mentioned to be optional in the following
@@ -250,14 +262,16 @@ struct vdpa_config_ops {
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
- int nvqs, size_t size, const char
*name);
+ int nvqs, size_t size,
+ const char *name, bool use_va);
-#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs, name) \
+#define vdpa_alloc_device(dev_struct, member, parent, config, \
+ nvqs, name, use_va) \
container_of(__vdpa_alloc_device( \
parent, config, nvqs, \
sizeof(dev_struct) + \
BUILD_BUG_ON_ZERO(offsetof( \
- dev_struct, member)), name), \
+ dev_struct, member)), name, use_va), \
dev_struct, member)
int vdpa_register_device(struct vdpa_device *vdev);
