On 2021/1/20 ??3:10, Yongji Xie wrote:> On Wed, Jan 20, 2021 at 1:55 PM Jason Wang <jasowang at redhat.com>
wrote:
>>
>> On 2021/1/19 ??12:59, Xie Yongji wrote:
>>> This patches introduces SVA (Shared Virtual Addressing)
>>> support for vDPA device. During vDPA device allocation,
>>> vDPA device driver needs to indicate whether SVA is
>>> supported by the device. Then vhost-vdpa bus driver
>>> will not pin user page and transfer userspace virtual
>>> address instead of physical address during DMA mapping.
>>>
>>> Suggested-by: Jason Wang <jasowang at redhat.com>
>>> Signed-off-by: Xie Yongji <xieyongji at bytedance.com>
>>> ---
>>> drivers/vdpa/ifcvf/ifcvf_main.c | 2 +-
>>> drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
>>> drivers/vdpa/vdpa.c | 5 ++++-
>>> drivers/vdpa/vdpa_sim/vdpa_sim.c | 3 ++-
>>> drivers/vhost/vdpa.c | 35
+++++++++++++++++++++++------------
>>> include/linux/vdpa.h | 10 +++++++---
>>> 6 files changed, 38 insertions(+), 19 deletions(-)
>>>
>>> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c
b/drivers/vdpa/ifcvf/ifcvf_main.c
>>> index 23474af7da40..95c4601f82f5 100644
>>> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
>>> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
>>> @@ -439,7 +439,7 @@ 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 77595c81488d..05988d6907f2 100644
>>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
>>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>>> @@ -1959,7 +1959,7 @@ 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 32bd48baffab..50cab930b2e5 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.
>>> + * @sva: indicate whether SVA (Shared Virtual Addressing) is
supported
>>> *
>>> * 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 sva)
>>> {
>>> struct vdpa_device *vdev;
>>> int err = -EINVAL;
>>> @@ -108,6 +110,7 @@ struct vdpa_device *__vdpa_alloc_device(struct
device *parent,
>>> vdev->config = config;
>>> vdev->features_valid = false;
>>> vdev->nvqs = nvqs;
>>> + vdev->sva = sva;
>>>
>>> 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 85776e4e6749..03c796873a6b 100644
>>> --- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
>>> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
>>> @@ -367,7 +367,8 @@ static struct vdpasim *vdpasim_create(const
char *name)
>>> else
>>> ops = &vdpasim_net_config_ops;
>>>
>>> - vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
VDPASIM_VQ_NUM, name);
>>> + vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
>>> + VDPASIM_VQ_NUM, name, false);
>>> if (!vdpasim)
>>> goto err_alloc;
>>>
>>> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
>>> index 4a241d380c40..36b6950ba37f 100644
>>> --- a/drivers/vhost/vdpa.c
>>> +++ b/drivers/vhost/vdpa.c
>>> @@ -486,21 +486,25 @@ 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 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->sva) {
>>> + 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);
>>> }
>>> - atomic64_sub(map->size >> PAGE_SHIFT,
&dev->mm->pinned_vm);
>>> vhost_iotlb_map_free(iotlb, map);
>>> }
>>> }
>>> @@ -558,13 +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->sva)
>>> 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)
>>> @@ -589,6 +595,7 @@ 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;
>>> struct page **page_list;
>>> unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
>>> @@ -607,6 +614,10 @@ static int
vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
>>> msg->iova + msg->size -
1))
>>> return -EEXIST;
>>>
>>> + if (vdpa->sva)
>>> + return vhost_vdpa_map(v, msg->iova, msg->size,
>>> + msg->uaddr, msg->perm);
>>> +
>>> /* Limit the use of memory for bookkeeping */
>>> page_list = (struct page **) __get_free_page(GFP_KERNEL);
>>> if (!page_list)
>>> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
>>> index cb5a3d847af3..f86869651614 100644
>>> --- a/include/linux/vdpa.h
>>> +++ b/include/linux/vdpa.h
>>> @@ -44,6 +44,7 @@ struct vdpa_parent_dev;
>>> * @config: the configuration ops for this device.
>>> * @index: device index
>>> * @features_valid: were features initialized? for legacy guests
>>> + * @sva: indicate whether SVA (Shared Virtual Addressing) is
supported
>>
>> Rethink about this. I think we probably need a better name other than
>> "sva" since kernel already use that for shared virtual
address space.
>> But actually we don't the whole virtual address space.
>>
> This flag is used to tell vhost-vdpa bus driver to transfer virtual
> addresses instead of physical addresses. So how about "use_va?,
> ?need_va" or "va??
I think "use_va" or "need_va" should be fine.
Thanks
>
>> And I guess this can not work for the device that use platform IOMMU,
so
>> we should check and fail if sva && !(dma_map || set_map).
>>
> Agree.
>
> Thanks,
> Yongji
>