Re: [PATCH net-next 08/11] sfc: implement device status related vdpa config operations
From: Jason Wang
Date: Wed Dec 14 2022 - 01:47:11 EST
On Wed, Dec 7, 2022 at 10:57 PM Gautam Dawar <gautam.dawar@xxxxxxx> wrote:
>
> vDPA config opertions to handle get/set device status and device
> reset have been implemented.
>
> Signed-off-by: Gautam Dawar <gautam.dawar@xxxxxxx>
> ---
> drivers/net/ethernet/sfc/ef100_vdpa.c | 7 +-
> drivers/net/ethernet/sfc/ef100_vdpa.h | 1 +
> drivers/net/ethernet/sfc/ef100_vdpa_ops.c | 133 ++++++++++++++++++++++
> 3 files changed, 140 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.c b/drivers/net/ethernet/sfc/ef100_vdpa.c
> index 04d64bfe3c93..80bca281a748 100644
> --- a/drivers/net/ethernet/sfc/ef100_vdpa.c
> +++ b/drivers/net/ethernet/sfc/ef100_vdpa.c
> @@ -225,9 +225,14 @@ static int vdpa_allocate_vis(struct efx_nic *efx, unsigned int *allocated_vis)
>
> static void ef100_vdpa_delete(struct efx_nic *efx)
> {
> + struct vdpa_device *vdpa_dev;
> +
> if (efx->vdpa_nic) {
> + vdpa_dev = &efx->vdpa_nic->vdpa_dev;
> + ef100_vdpa_reset(vdpa_dev);
Any reason we need to reset during delete?
> +
> /* replace with _vdpa_unregister_device later */
> - put_device(&efx->vdpa_nic->vdpa_dev.dev);
> + put_device(&vdpa_dev->dev);
> efx->vdpa_nic = NULL;
> }
> efx_mcdi_free_vis(efx);
> diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.h b/drivers/net/ethernet/sfc/ef100_vdpa.h
> index a33edd6dda12..1b0bbba88154 100644
> --- a/drivers/net/ethernet/sfc/ef100_vdpa.h
> +++ b/drivers/net/ethernet/sfc/ef100_vdpa.h
> @@ -186,6 +186,7 @@ int ef100_vdpa_add_filter(struct ef100_vdpa_nic *vdpa_nic,
> enum ef100_vdpa_mac_filter_type type);
> int ef100_vdpa_irq_vectors_alloc(struct pci_dev *pci_dev, u16 nvqs);
> void ef100_vdpa_irq_vectors_free(void *data);
> +int ef100_vdpa_reset(struct vdpa_device *vdev);
>
> static inline bool efx_vdpa_is_little_endian(struct ef100_vdpa_nic *vdpa_nic)
> {
> diff --git a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
> index 132ddb4a647b..718b67f6da90 100644
> --- a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
> +++ b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
> @@ -251,6 +251,62 @@ static bool is_qid_invalid(struct ef100_vdpa_nic *vdpa_nic, u16 idx,
> return false;
> }
>
> +static void ef100_reset_vdpa_device(struct ef100_vdpa_nic *vdpa_nic)
> +{
> + int i;
> +
> + WARN_ON(!mutex_is_locked(&vdpa_nic->lock));
> +
> + if (!vdpa_nic->status)
> + return;
> +
> + vdpa_nic->vdpa_state = EF100_VDPA_STATE_INITIALIZED;
> + vdpa_nic->status = 0;
> + vdpa_nic->features = 0;
> + for (i = 0; i < (vdpa_nic->max_queue_pairs * 2); i++)
> + reset_vring(vdpa_nic, i);
> +}
> +
> +/* May be called under the rtnl lock */
> +int ef100_vdpa_reset(struct vdpa_device *vdev)
> +{
> + struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> + /* vdpa device can be deleted anytime but the bar_config
> + * could still be vdpa and hence efx->state would be STATE_VDPA.
> + * Accordingly, ensure vdpa device exists before reset handling
> + */
> + if (!vdpa_nic)
> + return -ENODEV;
> +
> + mutex_lock(&vdpa_nic->lock);
> + ef100_reset_vdpa_device(vdpa_nic);
> + mutex_unlock(&vdpa_nic->lock);
> + return 0;
> +}
> +
> +static int start_vdpa_device(struct ef100_vdpa_nic *vdpa_nic)
> +{
> + int rc = 0;
> + int i, j;
> +
> + for (i = 0; i < (vdpa_nic->max_queue_pairs * 2); i++) {
> + if (can_create_vring(vdpa_nic, i)) {
> + rc = create_vring(vdpa_nic, i);
So I think we can safely remove the create_vring() in set_vq_ready()
since it's undefined behaviour if set_vq_ready() is called after
DRIVER_OK.
> + if (rc)
> + goto clear_vring;
> + }
> + }
> + vdpa_nic->vdpa_state = EF100_VDPA_STATE_STARTED;
> + return rc;
> +
> +clear_vring:
> + for (j = 0; j < i; j++)
> + if (vdpa_nic->vring[j].vring_created)
> + delete_vring(vdpa_nic, j);
> + return rc;
> +}
> +
> static int ef100_vdpa_set_vq_address(struct vdpa_device *vdev,
> u16 idx, u64 desc_area, u64 driver_area,
> u64 device_area)
> @@ -568,6 +624,80 @@ static u32 ef100_vdpa_get_vendor_id(struct vdpa_device *vdev)
> return EF100_VDPA_VENDOR_ID;
> }
>
> +static u8 ef100_vdpa_get_status(struct vdpa_device *vdev)
> +{
> + struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> + u8 status;
> +
> + mutex_lock(&vdpa_nic->lock);
> + status = vdpa_nic->status;
> + mutex_unlock(&vdpa_nic->lock);
> + return status;
> +}
> +
> +static void ef100_vdpa_set_status(struct vdpa_device *vdev, u8 status)
> +{
> + struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> + u8 new_status;
> + int rc;
> +
> + mutex_lock(&vdpa_nic->lock);
> + if (!status) {
> + dev_info(&vdev->dev,
> + "%s: Status received is 0. Device reset being done\n",
> + __func__);
> + ef100_reset_vdpa_device(vdpa_nic);
> + goto unlock_return;
> + }
> + new_status = status & ~vdpa_nic->status;
> + if (new_status == 0) {
> + dev_info(&vdev->dev,
> + "%s: New status same as current status\n", __func__);
> + goto unlock_return;
> + }
> + if (new_status & VIRTIO_CONFIG_S_FAILED) {
> + ef100_reset_vdpa_device(vdpa_nic);
> + goto unlock_return;
> + }
> +
> + if (new_status & VIRTIO_CONFIG_S_ACKNOWLEDGE &&
> + vdpa_nic->vdpa_state == EF100_VDPA_STATE_INITIALIZED) {
As replied before, I think there's no need to check
EF100_VDPA_STATE_INITIALIZED, otherwise it could be a bug somewhere.
> + vdpa_nic->status |= VIRTIO_CONFIG_S_ACKNOWLEDGE;
> + new_status &= ~VIRTIO_CONFIG_S_ACKNOWLEDGE;
> + }
> + if (new_status & VIRTIO_CONFIG_S_DRIVER &&
> + vdpa_nic->vdpa_state == EF100_VDPA_STATE_INITIALIZED) {
> + vdpa_nic->status |= VIRTIO_CONFIG_S_DRIVER;
> + new_status &= ~VIRTIO_CONFIG_S_DRIVER;
> + }
> + if (new_status & VIRTIO_CONFIG_S_FEATURES_OK &&
> + vdpa_nic->vdpa_state == EF100_VDPA_STATE_INITIALIZED) {
> + vdpa_nic->status |= VIRTIO_CONFIG_S_FEATURES_OK;
> + vdpa_nic->vdpa_state = EF100_VDPA_STATE_NEGOTIATED;
I think we can simply map EF100_VDPA_STATE_NEGOTIATED to
VIRTIO_CONFIG_S_FEATURES_OK.
E.g the code doesn't fail the feature negotiation by clearing the
VIRTIO_CONFIG_S_FEATURES_OK when ef100_vdpa_set_driver_feature fails?
Thanks