? 2021/6/3 ??3:38, Eli Cohen ??:> On Thu, Jun 03, 2021 at 03:11:51PM +0800, Jason Wang wrote:
>> ? 2021/6/2 ??5:53, Eli Cohen ??:
>>> Implement mlx5_get_vq_notification() to return the doorbell
address.
>>> Since the notification area is mapped to userspace, make sure that
the
>>> BAR size is at least PAGE_SIZE large.
>>>
>>> Signed-off-by: Eli Cohen <elic at nvidia.com>
>>> ---
>>> v0 --> v1:
>>> Make sure SF bar size is not smaller than PAGE_SIZE
>>>
>>> drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 +
>>> drivers/vdpa/mlx5/core/resources.c | 1 +
>>> drivers/vdpa/mlx5/net/mlx5_vnet.c | 17 +++++++++++++++++
>>> 3 files changed, 19 insertions(+)
>>>
>>> diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
>>> index 09a16a3d1b2a..0002b2136b48 100644
>>> --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
>>> +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
>>> @@ -42,6 +42,7 @@ struct mlx5_vdpa_resources {
>>> u32 pdn;
>>> struct mlx5_uars_page *uar;
>>> void __iomem *kick_addr;
>>> + u64 phys_kick_addr;
>>> u16 uid;
>>> u32 null_mkey;
>>> bool valid;
>>> diff --git a/drivers/vdpa/mlx5/core/resources.c
b/drivers/vdpa/mlx5/core/resources.c
>>> index 836ab9ef0fa6..d4606213f88a 100644
>>> --- a/drivers/vdpa/mlx5/core/resources.c
>>> +++ b/drivers/vdpa/mlx5/core/resources.c
>>> @@ -253,6 +253,7 @@ int mlx5_vdpa_alloc_resources(struct
mlx5_vdpa_dev *mvdev)
>>> goto err_key;
>>> kick_addr = mdev->bar_addr + offset;
>>> + res->phys_kick_addr = kick_addr;
>>> res->kick_addr = ioremap(kick_addr, PAGE_SIZE);
>>> if (!res->kick_addr) {
>>> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>>> index 5500bcfe84b4..1936039e05bd 100644
>>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
>>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>>> @@ -1871,8 +1871,25 @@ static void mlx5_vdpa_free(struct
vdpa_device *vdev)
>>> static struct vdpa_notification_area
mlx5_get_vq_notification(struct vdpa_device *vdev, u16 idx)
>>> {
>>> + struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
>>> struct vdpa_notification_area ret = {};
>>> + struct mlx5_vdpa_net *ndev;
>>> + phys_addr_t addr;
>>> +
>>> + /* If SF BAR size is smaller than PAGE_SIZE, do not use direct
>>> + * notification to avoid the risk of mapping pages that contain
BAR of more
>>> + * than one SF
>>> + */
>>> + if (MLX5_CAP_GEN(mvdev->mdev, log_min_sf_size) + 12 <
PAGE_SHIFT)
>>> + return ret;
>>> +
>>> + ndev = to_mlx5_vdpa_ndev(mvdev);
>>> + addr = (phys_addr_t)ndev->mvdev.res.phys_kick_addr;
>>> + if (addr & ~PAGE_MASK)
>>> + return ret;
>>
>> This has been checked by vhost-vDPA, and it's better to leave those
policy
>> checking to them driver instead of checking it in the parent.
>>
> Not in all invocations of get_vq_notification(). For example, in
> vhost_vdpa_fault() you call remap_pfn_range() with notify.addr >>
> PAGE_SHIFT so it it was not aligned you mask this misalignment.
In order to have vhost_vdpa_fault() works, it should first pass the
check of vhost_vdpa_mmap().
Othewise we won't install vma->vm_ops so there won't be a page fault
for
the doorbell.
Thanks
>
>> Thanks
>>
>>
>>> + ret.addr = (phys_addr_t)ndev->mvdev.res.phys_kick_addr;
>>> + ret.size = PAGE_SIZE;
>>> return ret;
>>> }