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References: <20221207145428.31544-1-gautam.dawar@amd.com> <20221207145428.31544-7-gautam.dawar@amd.com>
In-Reply-To: <20221207145428.31544-7-gautam.dawar@amd.com>
From:   Jason Wang <jasowang@redhat.com>
Date:   Wed, 14 Dec 2022 14:45:00 +0800
Message-ID: <CACGkMEvPK+hkF9WU8_EenRQ5fufFqedrHtiPmeks_FFF6NAEmg@mail.gmail.com>
Subject: Re: [PATCH net-next 06/11] sfc: implement vdpa vring config operations
To:     Gautam Dawar <gautam.dawar@amd.com>
Cc:     linux-net-drivers@amd.com, netdev@vger.kernel.org,
        eperezma@redhat.com, tanuj.kamde@amd.com, Koushik.Dutta@amd.com,
        harpreet.anand@amd.com, Edward Cree <ecree.xilinx@gmail.com>,
        Martin Habets <habetsm.xilinx@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, Dec 7, 2022 at 10:56 PM Gautam Dawar <gautam.dawar@amd.com> wrote:
>
> This patch implements the vDPA config operations related to
> virtqueues or vrings. These include setting vring address,
> getting vq state, operations to enable/disable a vq etc.
> The resources required for vring operations eg. VI, interrupts etc.
> are also allocated.
>
> Signed-off-by: Gautam Dawar <gautam.dawar@amd.com>
> ---
>  drivers/net/ethernet/sfc/ef100_vdpa.c     |  58 ++-
>  drivers/net/ethernet/sfc/ef100_vdpa.h     |  55 +++
>  drivers/net/ethernet/sfc/ef100_vdpa_ops.c | 449 +++++++++++++++++++++-
>  3 files changed, 560 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.c b/drivers/net/ethernet/sfc/ef100_vdpa.c
> index ff4bb61e598e..41eb7aef6798 100644
> --- a/drivers/net/ethernet/sfc/ef100_vdpa.c
> +++ b/drivers/net/ethernet/sfc/ef100_vdpa.c
> @@ -15,6 +15,7 @@
>  #include "ef100_vdpa.h"
>  #include "mcdi_vdpa.h"
>  #include "mcdi_filters.h"
> +#include "mcdi_functions.h"
>  #include "ef100_netdev.h"
>
>  static struct virtio_device_id ef100_vdpa_id_table[] = {
> @@ -48,6 +49,24 @@ int ef100_vdpa_init(struct efx_probe_data *probe_data)
>         return rc;
>  }
>
> +static int vdpa_allocate_vis(struct efx_nic *efx, unsigned int *allocated_vis)
> +{
> +       /* The first VI is reserved for MCDI
> +        * 1 VI each for rx + tx ring
> +        */
> +       unsigned int max_vis = 1 + EF100_VDPA_MAX_QUEUES_PAIRS;
> +       unsigned int min_vis = 1 + 1;
> +       int rc;
> +
> +       rc = efx_mcdi_alloc_vis(efx, min_vis, max_vis,
> +                               NULL, allocated_vis);
> +       if (!rc)
> +               return rc;
> +       if (*allocated_vis < min_vis)
> +               return -ENOSPC;
> +       return 0;
> +}
> +
>  static void ef100_vdpa_delete(struct efx_nic *efx)
>  {
>         if (efx->vdpa_nic) {
> @@ -55,6 +74,7 @@ static void ef100_vdpa_delete(struct efx_nic *efx)
>                 put_device(&efx->vdpa_nic->vdpa_dev.dev);
>                 efx->vdpa_nic = NULL;
>         }
> +       efx_mcdi_free_vis(efx);
>  }
>
>  void ef100_vdpa_fini(struct efx_probe_data *probe_data)
> @@ -106,10 +126,20 @@ static struct ef100_vdpa_nic *ef100_vdpa_create(struct efx_nic *efx,
>  {
>         struct ef100_nic_data *nic_data = efx->nic_data;
>         struct ef100_vdpa_nic *vdpa_nic;
> +       unsigned int allocated_vis;
>         struct device *dev;
>         int rc;
> +       u8 i;
>
>         nic_data->vdpa_class = dev_type;
> +       rc = vdpa_allocate_vis(efx, &allocated_vis);
> +       if (rc) {
> +               pci_err(efx->pci_dev,
> +                       "%s Alloc VIs failed for vf:%u error:%d\n",
> +                        __func__, nic_data->vf_index, rc);
> +               return ERR_PTR(rc);
> +       }
> +
>         vdpa_nic = vdpa_alloc_device(struct ef100_vdpa_nic,
>                                      vdpa_dev, &efx->pci_dev->dev,
>                                      &ef100_vdpa_config_ops,
> @@ -120,7 +150,8 @@ static struct ef100_vdpa_nic *ef100_vdpa_create(struct efx_nic *efx,
>                         "vDPA device allocation failed for vf: %u\n",
>                         nic_data->vf_index);
>                 nic_data->vdpa_class = EF100_VDPA_CLASS_NONE;
> -               return ERR_PTR(-ENOMEM);
> +               rc = -ENOMEM;
> +               goto err_alloc_vis_free;
>         }
>
>         mutex_init(&vdpa_nic->lock);
> @@ -129,6 +160,7 @@ static struct ef100_vdpa_nic *ef100_vdpa_create(struct efx_nic *efx,
>         vdpa_nic->vdpa_dev.dma_dev = &efx->pci_dev->dev;
>         vdpa_nic->vdpa_dev.mdev = efx->mgmt_dev;
>         vdpa_nic->efx = efx;
> +       vdpa_nic->max_queue_pairs = allocated_vis - 1;
>         vdpa_nic->pf_index = nic_data->pf_index;
>         vdpa_nic->vf_index = nic_data->vf_index;
>         vdpa_nic->vdpa_state = EF100_VDPA_STATE_INITIALIZED;
> @@ -136,6 +168,27 @@ static struct ef100_vdpa_nic *ef100_vdpa_create(struct efx_nic *efx,
>         ether_addr_copy(vdpa_nic->mac_address, mac);
>         vdpa_nic->mac_configured = true;
>
> +       for (i = 0; i < (2 * vdpa_nic->max_queue_pairs); i++)
> +               vdpa_nic->vring[i].irq = -EINVAL;
> +
> +       rc = ef100_vdpa_irq_vectors_alloc(efx->pci_dev,
> +                                         vdpa_nic->max_queue_pairs * 2);
> +       if (rc < 0) {
> +               pci_err(efx->pci_dev,
> +                       "vDPA IRQ alloc failed for vf: %u err:%d\n",
> +                       nic_data->vf_index, rc);
> +               goto err_put_device;
> +       }

Is it possible to move irq allocation/free to set_status()? This is
what other vDPA drivers did and it helped to save resources.

> +
> +       rc = devm_add_action_or_reset(&efx->pci_dev->dev,
> +                                     ef100_vdpa_irq_vectors_free,
> +                                     efx->pci_dev);
> +       if (rc) {
> +               pci_err(efx->pci_dev,
> +                       "Failed adding devres for freeing irq vectors\n");
> +               goto err_put_device;
> +       }
> +
>         rc = get_net_config(vdpa_nic);
>         if (rc)
>                 goto err_put_device;
> @@ -147,6 +200,9 @@ static struct ef100_vdpa_nic *ef100_vdpa_create(struct efx_nic *efx,
>  err_put_device:
>         /* put_device invokes ef100_vdpa_free */
>         put_device(&vdpa_nic->vdpa_dev.dev);
> +
> +err_alloc_vis_free:
> +       efx_mcdi_free_vis(efx);
>         return ERR_PTR(rc);
>  }
>
> diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.h b/drivers/net/ethernet/sfc/ef100_vdpa.h
> index be7650c3166a..3cc33daa0431 100644
> --- a/drivers/net/ethernet/sfc/ef100_vdpa.h
> +++ b/drivers/net/ethernet/sfc/ef100_vdpa.h
> @@ -33,6 +33,20 @@
>  /* Alignment requirement of the Virtqueue */
>  #define EF100_VDPA_VQ_ALIGN 4096
>
> +/* Vring configuration definitions */
> +#define EF100_VRING_ADDRESS_CONFIGURED 0x1
> +#define EF100_VRING_SIZE_CONFIGURED 0x10
> +#define EF100_VRING_READY_CONFIGURED 0x100
> +#define EF100_VRING_CONFIGURED (EF100_VRING_ADDRESS_CONFIGURED | \
> +                               EF100_VRING_SIZE_CONFIGURED | \
> +                               EF100_VRING_READY_CONFIGURED)
> +
> +/* Maximum size of msix name */
> +#define EF100_VDPA_MAX_MSIX_NAME_SIZE 256
> +
> +/* Default high IOVA for MCDI buffer */
> +#define EF100_VDPA_IOVA_BASE_ADDR 0x20000000000
> +
>  /**
>   * enum ef100_vdpa_nic_state - possible states for a vDPA NIC
>   *
> @@ -58,6 +72,43 @@ enum ef100_vdpa_vq_type {
>         EF100_VDPA_VQ_NTYPES
>  };
>
> +/**
> + * struct ef100_vdpa_vring_info - vDPA vring data structure
> + *
> + * @desc: Descriptor area address of the vring
> + * @avail: Available area address of the vring
> + * @used: Device area address of the vring
> + * @size: Number of entries in the vring
> + * @vring_state: bit map to track vring configuration
> + * @vring_created: set to true when vring is created.

I wonder if we can merge vring_created into one bit of the vring_state.

> + * @last_avail_idx: last available index of the vring
> + * @last_used_idx: last used index of the vring
> + * @doorbell_offset: doorbell offset
> + * @doorbell_offset_valid: true if @doorbell_offset is updated
> + * @vring_type: type of vring created
> + * @vring_ctx: vring context information
> + * @msix_name: device name for vring irq handler
> + * @irq: irq number for vring irq handler
> + * @cb: callback for vring interrupts
> + */
> +struct ef100_vdpa_vring_info {
> +       dma_addr_t desc;
> +       dma_addr_t avail;
> +       dma_addr_t used;
> +       u32 size;
> +       u16 vring_state;
> +       bool vring_created;
> +       u32 last_avail_idx;
> +       u32 last_used_idx;
> +       u32 doorbell_offset;
> +       bool doorbell_offset_valid;
> +       enum ef100_vdpa_vq_type vring_type;
> +       struct efx_vring_ctx *vring_ctx;
> +       char msix_name[EF100_VDPA_MAX_MSIX_NAME_SIZE];
> +       u32 irq;
> +       struct vdpa_callback cb;
> +};
> +
>  /**
>   *  struct ef100_vdpa_nic - vDPA NIC data structure
>   *
> @@ -71,6 +122,7 @@ enum ef100_vdpa_vq_type {
>   * @features: negotiated feature bits
>   * @max_queue_pairs: maximum number of queue pairs supported
>   * @net_config: virtio_net_config data
> + * @vring: vring information of the vDPA device.
>   * @mac_address: mac address of interface associated with this vdpa device
>   * @mac_configured: true after MAC address is configured
>   * @cfg_cb: callback for config change
> @@ -87,6 +139,7 @@ struct ef100_vdpa_nic {
>         u64 features;
>         u32 max_queue_pairs;
>         struct virtio_net_config net_config;
> +       struct ef100_vdpa_vring_info vring[EF100_VDPA_MAX_QUEUES_PAIRS * 2];
>         u8 *mac_address;
>         bool mac_configured;
>         struct vdpa_callback cfg_cb;
> @@ -96,6 +149,8 @@ int ef100_vdpa_init(struct efx_probe_data *probe_data);
>  void ef100_vdpa_fini(struct efx_probe_data *probe_data);
>  int ef100_vdpa_register_mgmtdev(struct efx_nic *efx);
>  void ef100_vdpa_unregister_mgmtdev(struct efx_nic *efx);
> +int ef100_vdpa_irq_vectors_alloc(struct pci_dev *pci_dev, u16 nvqs);
> +void ef100_vdpa_irq_vectors_free(void *data);
>
>  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 87899baa1c52..b7efd3e0c901 100644
> --- a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
> +++ b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
> @@ -10,13 +10,441 @@
>
>  #include <linux/vdpa.h>
>  #include "ef100_vdpa.h"
> +#include "io.h"
>  #include "mcdi_vdpa.h"
>
> +/* Get the queue's function-local index of the associated VI
> + * virtqueue number queue 0 is reserved for MCDI
> + */
> +#define EFX_GET_VI_INDEX(vq_num) (((vq_num) / 2) + 1)
> +
>  static struct ef100_vdpa_nic *get_vdpa_nic(struct vdpa_device *vdev)
>  {
>         return container_of(vdev, struct ef100_vdpa_nic, vdpa_dev);
>  }
>
> +static irqreturn_t vring_intr_handler(int irq, void *arg)
> +{
> +       struct ef100_vdpa_vring_info *vring = arg;
> +
> +       if (vring->cb.callback)
> +               return vring->cb.callback(vring->cb.private);
> +
> +       return IRQ_NONE;
> +}
> +
> +int ef100_vdpa_irq_vectors_alloc(struct pci_dev *pci_dev, u16 nvqs)
> +{
> +       int rc;
> +
> +       rc = pci_alloc_irq_vectors(pci_dev, nvqs, nvqs, PCI_IRQ_MSIX);
> +       if (rc < 0)
> +               pci_err(pci_dev,
> +                       "Failed to alloc %d IRQ vectors, err:%d\n", nvqs, rc);
> +       return rc;
> +}
> +
> +void ef100_vdpa_irq_vectors_free(void *data)
> +{
> +       pci_free_irq_vectors(data);
> +}
> +
> +static int irq_vring_init(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       struct ef100_vdpa_vring_info *vring = &vdpa_nic->vring[idx];
> +       struct pci_dev *pci_dev = vdpa_nic->efx->pci_dev;
> +       int irq;
> +       int rc;
> +
> +       snprintf(vring->msix_name, 256, "x_vdpa[%s]-%d\n",
> +                pci_name(pci_dev), idx);
> +       irq = pci_irq_vector(pci_dev, idx);
> +       rc = devm_request_irq(&pci_dev->dev, irq, vring_intr_handler, 0,
> +                             vring->msix_name, vring);
> +       if (rc)
> +               pci_err(pci_dev,
> +                       "devm_request_irq failed for vring %d, rc %d\n",
> +                       idx, rc);
> +       else
> +               vring->irq = irq;
> +
> +       return rc;
> +}
> +
> +static void irq_vring_fini(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       struct ef100_vdpa_vring_info *vring = &vdpa_nic->vring[idx];
> +       struct pci_dev *pci_dev = vdpa_nic->efx->pci_dev;
> +
> +       devm_free_irq(&pci_dev->dev, vring->irq, vring);
> +       vring->irq = -EINVAL;
> +}
> +
> +static bool can_create_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       if (vdpa_nic->vring[idx].vring_state == EF100_VRING_CONFIGURED &&
> +           vdpa_nic->status & VIRTIO_CONFIG_S_DRIVER_OK &&
> +           !vdpa_nic->vring[idx].vring_created)
> +               return true;
> +
> +       return false;
> +}
> +
> +static int create_vring_ctx(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       struct efx_vring_ctx *vring_ctx;
> +       u32 vi_index;
> +
> +       if (idx % 2) /* Even VQ for RX and odd for TX */
> +               vdpa_nic->vring[idx].vring_type = EF100_VDPA_VQ_TYPE_NET_TXQ;
> +       else
> +               vdpa_nic->vring[idx].vring_type = EF100_VDPA_VQ_TYPE_NET_RXQ;
> +       vi_index = EFX_GET_VI_INDEX(idx);
> +                                       vdpa_nic->vring[idx].vring_type);
> +       if (IS_ERR(vring_ctx))
> +               return PTR_ERR(vring_ctx);
> +
> +       vdpa_nic->vring[idx].vring_ctx = vring_ctx;
> +       return 0;
> +}
> +
> +static void delete_vring_ctx(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       efx_vdpa_vring_fini(vdpa_nic->vring[idx].vring_ctx);
> +       vdpa_nic->vring[idx].vring_ctx = NULL;
> +}
> +
> +static int delete_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       struct efx_vring_dyn_cfg vring_dyn_cfg;
> +       int rc;
> +
> +       rc = efx_vdpa_vring_destroy(vdpa_nic->vring[idx].vring_ctx,
> +                                   &vring_dyn_cfg);
> +       if (rc)
> +               dev_err(&vdpa_nic->vdpa_dev.dev,
> +                       "%s: delete vring failed index:%u, err:%d\n",
> +                       __func__, idx, rc);
> +       vdpa_nic->vring[idx].last_avail_idx = vring_dyn_cfg.avail_idx;
> +       vdpa_nic->vring[idx].last_used_idx = vring_dyn_cfg.used_idx;
> +       vdpa_nic->vring[idx].vring_created = false;
> +
> +       irq_vring_fini(vdpa_nic, idx);
> +
> +       if (vdpa_nic->vring[idx].vring_ctx)
> +               delete_vring_ctx(vdpa_nic, idx);
> +
> +       return rc;
> +}
> +
> +static int create_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       struct efx_vring_dyn_cfg vring_dyn_cfg;
> +       struct efx_vring_ctx *vring_ctx;
> +       struct efx_vring_cfg vring_cfg;
> +       u32 offset;
> +       int rc;
> +
> +       if (!vdpa_nic->vring[idx].vring_ctx) {
> +               rc = create_vring_ctx(vdpa_nic, idx);
> +               if (rc) {
> +                       dev_err(&vdpa_nic->vdpa_dev.dev,
> +                               "%s: create_vring_ctx failed idx:%u, err:%d\n",
> +                               __func__, idx, rc);
> +                       return rc;
> +               }
> +       }
> +       vring_ctx = vdpa_nic->vring[idx].vring_ctx;
> +
> +       rc = irq_vring_init(vdpa_nic, idx);
> +       if (rc) {
> +               dev_err(&vdpa_nic->vdpa_dev.dev,
> +                       "%s: irq_vring_init failed. index:%u, err:%d\n",
> +                       __func__, idx, rc);
> +               goto err_irq_vring_init;
> +       }
> +       vring_cfg.desc = vdpa_nic->vring[idx].desc;
> +       vring_cfg.avail = vdpa_nic->vring[idx].avail;
> +       vring_cfg.used = vdpa_nic->vring[idx].used;
> +       vring_cfg.size = vdpa_nic->vring[idx].size;
> +       vring_cfg.features = vdpa_nic->features;
> +       vring_cfg.msix_vector = idx;
> +       vring_dyn_cfg.avail_idx = vdpa_nic->vring[idx].last_avail_idx;
> +       vring_dyn_cfg.used_idx = vdpa_nic->vring[idx].last_used_idx;
> +
> +       rc = efx_vdpa_vring_create(vring_ctx, &vring_cfg, &vring_dyn_cfg);
> +       if (rc) {
> +               dev_err(&vdpa_nic->vdpa_dev.dev,
> +                       "%s: vring_create failed index:%u, err:%d\n",
> +                       __func__, idx, rc);
> +               goto err_vring_create;
> +       }
> +       vdpa_nic->vring[idx].vring_created = true;
> +       if (!vdpa_nic->vring[idx].doorbell_offset_valid) {
> +               rc = efx_vdpa_get_doorbell_offset(vring_ctx, &offset);
> +               if (rc) {
> +                       dev_err(&vdpa_nic->vdpa_dev.dev,
> +                               "%s: get offset failed, index:%u err:%d\n",
> +                               __func__, idx, rc);
> +                       goto err_get_doorbell_offset;
> +               }
> +               vdpa_nic->vring[idx].doorbell_offset = offset;
> +               vdpa_nic->vring[idx].doorbell_offset_valid = true;
> +       }
> +
> +       return 0;
> +
> +err_get_doorbell_offset:
> +       efx_vdpa_vring_destroy(vdpa_nic->vring[idx].vring_ctx,
> +                              &vring_dyn_cfg);
> +       vdpa_nic->vring[idx].vring_created = false;
> +err_vring_create:
> +       irq_vring_fini(vdpa_nic, idx);
> +err_irq_vring_init:
> +       delete_vring_ctx(vdpa_nic, idx);
> +
> +       return rc;
> +}
> +
> +static void reset_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
> +{
> +       if (vdpa_nic->vring[idx].vring_created)
> +               delete_vring(vdpa_nic, idx);
> +
> +       memset((void *)&vdpa_nic->vring[idx], 0,
> +              sizeof(vdpa_nic->vring[idx]));
> +       vdpa_nic->vring[idx].vring_type = EF100_VDPA_VQ_NTYPES;
> +}
> +
> +static bool is_qid_invalid(struct ef100_vdpa_nic *vdpa_nic, u16 idx,
> +                          const char *caller)
> +{
> +       if (unlikely(idx >= (vdpa_nic->max_queue_pairs * 2))) {
> +               dev_err(&vdpa_nic->vdpa_dev.dev,
> +                       "%s: Invalid qid %u\n", caller, idx);
> +               return true;
> +       }
> +       return false;
> +}
> +
> +static int ef100_vdpa_set_vq_address(struct vdpa_device *vdev,
> +                                    u16 idx, u64 desc_area, u64 driver_area,
> +                                    u64 device_area)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return -EINVAL;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       vdpa_nic->vring[idx].desc = desc_area;
> +       vdpa_nic->vring[idx].avail = driver_area;
> +       vdpa_nic->vring[idx].used = device_area;
> +       vdpa_nic->vring[idx].vring_state |= EF100_VRING_ADDRESS_CONFIGURED;

Does this mean the NIC is unable to handle the case where the
virtqueue is mis-configured?

> +       mutex_unlock(&vdpa_nic->lock);
> +       return 0;
> +}
> +
> +static void ef100_vdpa_set_vq_num(struct vdpa_device *vdev, u16 idx, u32 num)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return;
> +
> +       if (!is_power_of_2(num)) {
> +               dev_err(&vdev->dev, "%s: Index:%u size:%u not power of 2\n",
> +                       __func__, idx, num);
> +               return;
> +       }
> +       if (num > EF100_VDPA_VQ_NUM_MAX_SIZE) {
> +               dev_err(&vdev->dev, "%s: Index:%u size:%u more than max:%u\n",
> +                       __func__, idx, num, EF100_VDPA_VQ_NUM_MAX_SIZE);
> +               return;
> +       }
> +       mutex_lock(&vdpa_nic->lock);
> +       vdpa_nic->vring[idx].size  = num;
> +       vdpa_nic->vring[idx].vring_state |= EF100_VRING_SIZE_CONFIGURED;
> +       mutex_unlock(&vdpa_nic->lock);
> +}
> +
> +static void ef100_vdpa_kick_vq(struct vdpa_device *vdev, u16 idx)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +       u32 idx_val;
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return;
> +
> +       if (!vdpa_nic->vring[idx].vring_created) {
> +               dev_err(&vdev->dev, "%s: Invalid vring%u\n", __func__, idx);
> +               return;
> +       }

This seems guest/user space trigger-able, if yes, let's avoid this warning.

> +
> +       idx_val = idx;
> +       _efx_writed(vdpa_nic->efx, cpu_to_le32(idx_val),
> +                   vdpa_nic->vring[idx].doorbell_offset);
> +}
> +
> +static void ef100_vdpa_set_vq_cb(struct vdpa_device *vdev, u16 idx,
> +                                struct vdpa_callback *cb)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return;
> +
> +       if (cb)
> +               vdpa_nic->vring[idx].cb = *cb;
> +}
> +
> +static void ef100_vdpa_set_vq_ready(struct vdpa_device *vdev, u16 idx,
> +                                   bool ready)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       if (ready) {
> +               vdpa_nic->vring[idx].vring_state |=
> +                                       EF100_VRING_READY_CONFIGURED;
> +               if (vdpa_nic->vdpa_state == EF100_VDPA_STATE_STARTED &&
> +                   can_create_vring(vdpa_nic, idx)) {

If this is the only caller of can_create_vring(), let's move the check
of vdpa_state into the can_create_vring().

> +                       if (create_vring(vdpa_nic, idx))
> +                               /* Rollback ready configuration
> +                                * So that the above layer driver
> +                                * can make another attempt to set ready
> +                                */
> +                               vdpa_nic->vring[idx].vring_state &=
> +                                       ~EF100_VRING_READY_CONFIGURED;
> +               }
> +       } else {
> +               vdpa_nic->vring[idx].vring_state &=
> +                                       ~EF100_VRING_READY_CONFIGURED;
> +               if (vdpa_nic->vring[idx].vring_created)
> +                       delete_vring(vdpa_nic, idx);
> +       }
> +       mutex_unlock(&vdpa_nic->lock);
> +}
> +
> +static bool ef100_vdpa_get_vq_ready(struct vdpa_device *vdev, u16 idx)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +       bool ready;
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return false;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       ready = vdpa_nic->vring[idx].vring_state & EF100_VRING_READY_CONFIGURED;
> +       mutex_unlock(&vdpa_nic->lock);
> +       return ready;
> +}
> +
> +static int ef100_vdpa_set_vq_state(struct vdpa_device *vdev, u16 idx,
> +                                  const struct vdpa_vq_state *state)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return -EINVAL;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       vdpa_nic->vring[idx].last_avail_idx = state->split.avail_index;

Should we update last_used_idx here as well?

> +       mutex_unlock(&vdpa_nic->lock);
> +       return 0;
> +}
> +
> +static int ef100_vdpa_get_vq_state(struct vdpa_device *vdev,
> +                                  u16 idx, struct vdpa_vq_state *state)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               return -EINVAL;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       state->split.avail_index = (u16)vdpa_nic->vring[idx].last_avail_idx;
> +       mutex_unlock(&vdpa_nic->lock);
> +
> +       return 0;
> +}
> +
> +static struct vdpa_notification_area
> +               ef100_vdpa_get_vq_notification(struct vdpa_device *vdev,
> +                                              u16 idx)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +       struct vdpa_notification_area notify_area = {0, 0};
> +       struct efx_vring_ctx *vring_ctx;
> +       struct efx_nic *efx;
> +       u32 offset;
> +       int rc;
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))
> +               goto end;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       vring_ctx = vdpa_nic->vring[idx].vring_ctx;
> +       if (!vring_ctx) {
> +               rc = create_vring_ctx(vdpa_nic, idx);

Interesting, in set_vq_ready() we call can_create_vring() before
create_vring(). The code here implies usespace can bypass that check,
is this intended?


> +               if (rc) {
> +                       dev_err(&vdpa_nic->vdpa_dev.dev,
> +                               "%s: vring ctx failed index:%u, err:%d\n",
> +                               __func__, idx, rc);
> +                       goto err_create_vring_ctx;
> +               }
> +               vring_ctx = vdpa_nic->vring[idx].vring_ctx;
> +       }
> +       if (!vdpa_nic->vring[idx].doorbell_offset_valid) {

I wonder if it's better to do this in the dev_add() since it is not
expected to be changed.

> +               rc = efx_vdpa_get_doorbell_offset(vring_ctx, &offset);
> +               if (rc) {
> +                       dev_err(&vdpa_nic->vdpa_dev.dev,
> +                               "%s: get_doorbell failed idx:%u, err:%d\n",
> +                               __func__, idx, rc);
> +                       goto err_get_doorbell_off;
> +               }
> +               vdpa_nic->vring[idx].doorbell_offset = offset;
> +               vdpa_nic->vring[idx].doorbell_offset_valid = true;
> +       }
> +
> +       efx = vdpa_nic->efx;
> +       notify_area.addr = (uintptr_t)(efx->membase_phys +
> +                               vdpa_nic->vring[idx].doorbell_offset);
> +       /* VDPA doorbells are at a stride of VI/2
> +        * One VI stride is shared by both rx & tx doorbells
> +        */
> +       notify_area.size = efx->vi_stride / 2;

Note that, if each area does not occupy a page, it means it can't be
mapped into userspace.

> +
> +       mutex_unlock(&vdpa_nic->lock);
> +       return notify_area;
> +
> +err_get_doorbell_off:
> +       delete_vring_ctx(vdpa_nic, idx);
> +err_create_vring_ctx:
> +       mutex_unlock(&vdpa_nic->lock);
> +end:
> +       return notify_area;
> +}
> +
> +static int ef100_get_vq_irq(struct vdpa_device *vdev, u16 idx)
> +{
> +       struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +       u32 irq;
> +
> +       if (is_qid_invalid(vdpa_nic, idx, __func__))

It might be easier to use a macro to implement is_qid_invalid() then
we don't need to __func__ trick.

Thanks


> +               return -EINVAL;
> +
> +       mutex_lock(&vdpa_nic->lock);
> +       irq = vdpa_nic->vring[idx].irq;
> +       mutex_unlock(&vdpa_nic->lock);
> +
> +       return irq;
> +}
> +
>  static u32 ef100_vdpa_get_vq_align(struct vdpa_device *vdev)
>  {
>         return EF100_VDPA_VQ_ALIGN;
> @@ -98,6 +526,8 @@ static void ef100_vdpa_set_config_cb(struct vdpa_device *vdev,
>
>         if (cb)
>                 vdpa_nic->cfg_cb = *cb;
> +       else
> +               memset(&vdpa_nic->cfg_cb, 0, sizeof(vdpa_nic->cfg_cb));
>  }
>
>  static u16 ef100_vdpa_get_vq_num_max(struct vdpa_device *vdev)
> @@ -155,11 +585,28 @@ static void ef100_vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
>  static void ef100_vdpa_free(struct vdpa_device *vdev)
>  {
>         struct ef100_vdpa_nic *vdpa_nic = get_vdpa_nic(vdev);
> +       int i;
>
> -       mutex_destroy(&vdpa_nic->lock);
> +       if (vdpa_nic) {
> +               for (i = 0; i < (vdpa_nic->max_queue_pairs * 2); i++)
> +                       reset_vring(vdpa_nic, i);
> +               ef100_vdpa_irq_vectors_free(vdpa_nic->efx->pci_dev);
> +               mutex_destroy(&vdpa_nic->lock);
> +               vdpa_nic->efx->vdpa_nic = NULL;
> +       }
>  }
>
>  const struct vdpa_config_ops ef100_vdpa_config_ops = {
> +       .set_vq_address      = ef100_vdpa_set_vq_address,
> +       .set_vq_num          = ef100_vdpa_set_vq_num,
> +       .kick_vq             = ef100_vdpa_kick_vq,
> +       .set_vq_cb           = ef100_vdpa_set_vq_cb,
> +       .set_vq_ready        = ef100_vdpa_set_vq_ready,
> +       .get_vq_ready        = ef100_vdpa_get_vq_ready,
> +       .set_vq_state        = ef100_vdpa_set_vq_state,
> +       .get_vq_state        = ef100_vdpa_get_vq_state,
> +       .get_vq_notification = ef100_vdpa_get_vq_notification,
> +       .get_vq_irq          = ef100_get_vq_irq,
>         .get_vq_align        = ef100_vdpa_get_vq_align,
>         .get_device_features = ef100_vdpa_get_device_features,
>         .set_driver_features = ef100_vdpa_set_driver_features,
> --
> 2.30.1
>