Re: [PATCH net-next v2 08/14] sfc: implement vdpa vring config operations

From: Gautam Dawar
Date: Mon Mar 13 2023 - 13:05:47 EST


On 3/8/23 22:36, Martin Habets wrote:
Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.


On Tue, Mar 07, 2023 at 05:06:10PM +0530, Gautam Dawar 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@xxxxxxx>
---
drivers/net/ethernet/sfc/ef100_vdpa.c | 46 +++-
drivers/net/ethernet/sfc/ef100_vdpa.h | 54 +++++
drivers/net/ethernet/sfc/ef100_vdpa_ops.c | 275 ++++++++++++++++++++++
3 files changed, 374 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.c b/drivers/net/ethernet/sfc/ef100_vdpa.c
index 4c5a98c9d6c3..c66e5aef69ea 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa.c
+++ b/drivers/net/ethernet/sfc/ef100_vdpa.c
@@ -14,6 +14,7 @@
#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[] = {
@@ -47,12 +48,31 @@ 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) {
/* replace with _vdpa_unregister_device later */
put_device(&efx->vdpa_nic->vdpa_dev.dev);
}
+ efx_mcdi_free_vis(efx);
}

void ef100_vdpa_fini(struct efx_probe_data *probe_data)
@@ -104,9 +124,19 @@ 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;
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,
@@ -117,7 +147,8 @@ 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);
@@ -125,11 +156,21 @@ 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;
vdpa_nic->mac_address = (u8 *)&vdpa_nic->net_config.mac;

+ for (i = 0; i < (2 * vdpa_nic->max_queue_pairs); i++) {
+ rc = ef100_vdpa_init_vring(vdpa_nic, i);
+ if (rc) {
+ pci_err(efx->pci_dev,
+ "vring init idx: %u failed, rc: %d\n", i, rc);
+ goto err_put_device;
+ }
+ }
+
rc = get_net_config(vdpa_nic);
if (rc)
goto err_put_device;
@@ -146,6 +187,9 @@ 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 dcf4a8156415..348ca8a7404b 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa.h
+++ b/drivers/net/ethernet/sfc/ef100_vdpa.h
@@ -32,6 +32,21 @@
/* 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)
+#define EF100_VRING_CREATED 0x1000
I only see these defines used a bit masks. So why skip all the bits
in stead of using 0x2, 0x4, 0x8 respectively?

There is no particular reason. I just re-used the macros and their values from the out of tree driver. Will change the to 0x1, 0x2, 0x4 and 0x8 respectively.

Thanks


Martin

+
+/* 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
*
@@ -57,6 +72,41 @@ 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
+ * @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;
+ 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
*
@@ -70,6 +120,7 @@ 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
@@ -86,6 +137,7 @@ 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;
@@ -95,6 +147,8 @@ 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);
+void ef100_vdpa_irq_vectors_free(void *data);
+int ef100_vdpa_init_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx);

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 a2364ef9f492..0051c4c0e47c 100644
--- a/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
+++ b/drivers/net/ethernet/sfc/ef100_vdpa_ops.c
@@ -9,13 +9,270 @@

#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);
}

+void ef100_vdpa_irq_vectors_free(void *data)
+{
+ pci_free_irq_vectors(data);
+}
+
+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);
+ vring_ctx = efx_vdpa_vring_init(vdpa_nic->efx, vi_index,
+ 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 void reset_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
+{
+ vdpa_nic->vring[idx].vring_type = EF100_VDPA_VQ_NTYPES;
+ vdpa_nic->vring[idx].vring_state = 0;
+ vdpa_nic->vring[idx].last_avail_idx = 0;
+ vdpa_nic->vring[idx].last_used_idx = 0;
+}
+
+int ef100_vdpa_init_vring(struct ef100_vdpa_nic *vdpa_nic, u16 idx)
+{
+ u32 offset;
+ int rc;
+
+ vdpa_nic->vring[idx].irq = -EINVAL;
+ 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;
+ }
+
+ rc = efx_vdpa_get_doorbell_offset(vdpa_nic->vring[idx].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_offset;
+ }
+ vdpa_nic->vring[idx].doorbell_offset = offset;
+ vdpa_nic->vring[idx].doorbell_offset_valid = true;
+
+ return 0;
+
+err_get_doorbell_offset:
+ delete_vring_ctx(vdpa_nic, idx);
+ return rc;
+}
+
+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;
+ 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_state & EF100_VRING_CREATED))
+ return;
+
+ 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;
+ } else {
+ vdpa_nic->vring[idx].vring_state &=
+ ~EF100_VRING_READY_CONFIGURED;
+ }
+ 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;
+ vdpa_nic->vring[idx].last_used_idx = state->split.avail_index;
+ 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_used_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};
+
+ if (is_qid_invalid(vdpa_nic, idx, __func__))
+ goto end;
+
+ mutex_lock(&vdpa_nic->lock);
+ notify_area.addr = (uintptr_t)(vdpa_nic->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 = vdpa_nic->efx->vi_stride / 2;
+ 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__))
+ 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;
@@ -80,6 +337,8 @@ 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)
@@ -137,14 +396,30 @@ 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;

if (vdpa_nic) {
+ for (i = 0; i < (vdpa_nic->max_queue_pairs * 2); i++) {
+ reset_vring(vdpa_nic, i);
+ if (vdpa_nic->vring[i].vring_ctx)
+ delete_vring_ctx(vdpa_nic, i);
+ }
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