src/vnet/devices/virtio/device.c - fdio/vpp - Gitiles

 /*
  *------------------------------------------------------------------
  * Copyright (c) 2016 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *------------------------------------------------------------------
  */

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <linux/virtio_net.h>
 #include <linux/vhost.h>

 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/ip/ip4_packet.h>
 #include <vnet/ip/ip6_packet.h>
 #include <vnet/devices/virtio/virtio.h>

 #define foreach_virtio_tx_func_error	       \
 _(NO_FREE_SLOTS, "no free tx slots")           \
 _(TRUNC_PACKET, "packet > buffer size -- truncated in tx ring") \
 _(PENDING_MSGS, "pending msgs in tx ring") \
 _(NO_TX_QUEUES, "no tx queues")

 typedef enum
 {
 #define _(f,s) TAP_TX_ERROR_##f,
   foreach_virtio_tx_func_error
 #undef _
     TAP_TX_N_ERROR,
 } virtio_tx_func_error_t;

 static char *virtio_tx_func_error_strings[] = {
 #define _(n,s) s,
   foreach_virtio_tx_func_error
 #undef _
 };

 u8 *
 format_virtio_device_name (u8 * s, va_list * args)
 {
   u32 dev_instance = va_arg (*args, u32);
   virtio_main_t *mm = &virtio_main;
   virtio_if_t *vif = pool_elt_at_index (mm->interfaces, dev_instance);

   if (vif->type == VIRTIO_IF_TYPE_TAP)
     {
       s = format (s, "tap%u", vif->id);
     }
   else
     s = format (s, "virtio%lu", vif->dev_instance);

   return s;
 }

 static u8 *
 format_virtio_device (u8 * s, va_list * args)
 {
   u32 dev_instance = va_arg (*args, u32);
   int verbose = va_arg (*args, int);
   u32 indent = format_get_indent (s);

   s = format (s, "VIRTIO interface");
   if (verbose)
     {
       s = format (s, "\n%U instance %u", format_white_space, indent + 2,
 		  dev_instance);
     }
   return s;
 }

 static u8 *
 format_virtio_tx_trace (u8 * s, va_list * args)
 {
   s = format (s, "Unimplemented...");
   return s;
 }

 inline void
 virtio_free_used_desc (vlib_main_t * vm, virtio_vring_t * vring)
 {
   u16 used = vring->desc_in_use;
   u16 sz = vring->size;
   u16 mask = sz - 1;
   u16 last = vring->last_used_idx;
   u16 n_left = vring->used->idx - last;

   if (n_left == 0)
     return;

   while (n_left)
     {
       struct vring_used_elem *e = &vring->used->ring[last & mask];
       u16 slot = e->id;
       struct vring_desc *d = &vring->desc[slot];

       if (PREDICT_FALSE (d->flags & VRING_DESC_F_INDIRECT))
 	{
 	  d = uword_to_pointer (d->addr, struct vring_desc *);
 	  vec_free (d);
 	}

       vlib_buffer_free (vm, &vring->buffers[slot], 1);
       used--;
       last++;
       n_left--;
     }
   vring->desc_in_use = used;
   vring->last_used_idx = last;
 }

 static_always_inline u16
 add_buffer_to_slot (vlib_main_t * vm, virtio_vring_t * vring, u32 bi,
 		    u16 avail, u16 next, u16 mask)
 {
   u16 n_added = 0;
   const int hdr_sz = sizeof (struct virtio_net_hdr_v1);
   struct vring_desc *d;
   d = &vring->desc[next];
   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
   struct virtio_net_hdr_v1 *hdr = vlib_buffer_get_current (b) - hdr_sz;

   clib_memset (hdr, 0, hdr_sz);

   if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
     {
       d->addr = pointer_to_uword (vlib_buffer_get_current (b)) - hdr_sz;
       d->len = b->current_length + hdr_sz;
       d->flags = 0;
     }
   else
     {
       struct vring_desc *id, *descs = 0;

       /* first buffer in chain */
       vec_add2_aligned (descs, id, 1, CLIB_CACHE_LINE_BYTES);
       id->addr = pointer_to_uword (vlib_buffer_get_current (b)) - hdr_sz;
       id->len = b->current_length + hdr_sz;

       while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
 	{
 	  id->flags = VRING_DESC_F_NEXT;
 	  id->next = vec_len (descs);
 	  vec_add2_aligned (descs, id, 1, CLIB_CACHE_LINE_BYTES);
 	  b = vlib_get_buffer (vm, b->next_buffer);
 	  id->addr = pointer_to_uword (vlib_buffer_get_current (b));
 	  id->len = b->current_length;
 	}

       d->addr = pointer_to_uword (descs);
       d->len = vec_len (descs) * sizeof (struct vring_desc);
       d->flags = VRING_DESC_F_INDIRECT;
     }
   vring->buffers[next] = bi;
   vring->avail->ring[avail & mask] = next;
   n_added++;
   return n_added;
 }


 static_always_inline uword
 virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 			    vlib_frame_t * frame, virtio_if_t * vif)
 {
   u8 qid = 0;
   u16 n_left = frame->n_vectors;
   virtio_vring_t *vring = vec_elt_at_index (vif->vrings, (qid << 1) + 1);
   u16 used, next, avail;
   u16 sz = vring->size;
   u16 mask = sz - 1;
   u32 *buffers = vlib_frame_args (frame);

   clib_spinlock_lock_if_init (&vif->lockp);

   /* free consumed buffers */
   virtio_free_used_desc (vm, vring);

   used = vring->desc_in_use;
   next = vring->desc_next;
   avail = vring->avail->idx;

   while (n_left && used < sz)
     {
       u16 n_added;
       n_added = add_buffer_to_slot (vm, vring, buffers[0], avail, next, mask);
       avail += n_added;
       next = (next + n_added) & mask;
       used += n_added;
       buffers++;
       n_left--;
     }

   if (n_left != frame->n_vectors)
     {
       CLIB_MEMORY_STORE_BARRIER ();
       vring->avail->idx = avail;
       vring->desc_next = next;
       vring->desc_in_use = used;
       if ((vring->used->flags & VIRTIO_RING_FLAG_MASK_INT) == 0)
 	{
 	  u64 x = 1;
 	  CLIB_UNUSED (int r) = write (vring->kick_fd, &x, sizeof (x));
 	}
     }


   if (n_left)
     {
       vlib_error_count (vm, node->node_index, TAP_TX_ERROR_NO_FREE_SLOTS,
 			n_left);
       vlib_buffer_free (vm, buffers, n_left);
     }

   clib_spinlock_unlock_if_init (&vif->lockp);

   return frame->n_vectors - n_left;
 }

 static uword
 virtio_interface_tx (vlib_main_t * vm,
 		     vlib_node_runtime_t * node, vlib_frame_t * frame)
 {
   virtio_main_t *nm = &virtio_main;
   vnet_interface_output_runtime_t *rund = (void *) node->runtime_data;
   virtio_if_t *vif = pool_elt_at_index (nm->interfaces, rund->dev_instance);

   return virtio_interface_tx_inline (vm, node, frame, vif);
 }

 static void
 virtio_set_interface_next_node (vnet_main_t * vnm, u32 hw_if_index,
 				u32 node_index)
 {
   virtio_main_t *apm = &virtio_main;
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   virtio_if_t *vif = pool_elt_at_index (apm->interfaces, hw->dev_instance);

   /* Shut off redirection */
   if (node_index == ~0)
     {
       vif->per_interface_next_index = node_index;
       return;
     }

   vif->per_interface_next_index =
     vlib_node_add_next (vlib_get_main (), virtio_input_node.index,
 			node_index);
 }

 static void
 virtio_clear_hw_interface_counters (u32 instance)
 {
   /* Nothing for now */
 }

 static clib_error_t *
 virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
 				 vnet_hw_interface_rx_mode mode)
 {
   virtio_main_t *mm = &virtio_main;
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
   virtio_vring_t *vring = vec_elt_at_index (vif->vrings, qid);

   if (mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
     vring->avail->flags |= VIRTIO_RING_FLAG_MASK_INT;
   else
     vring->avail->flags &= ~VIRTIO_RING_FLAG_MASK_INT;

   return 0;
 }

 static clib_error_t *
 virtio_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
 {
   virtio_main_t *mm = &virtio_main;
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);

   if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
     vif->flags |= VIRTIO_IF_FLAG_ADMIN_UP;
   else
     vif->flags &= ~VIRTIO_IF_FLAG_ADMIN_UP;

   return 0;
 }

 static clib_error_t *
 virtio_subif_add_del_function (vnet_main_t * vnm,
 			       u32 hw_if_index,
 			       struct vnet_sw_interface_t *st, int is_add)
 {
   /* Nothing for now */
   return 0;
 }

 /* *INDENT-OFF* */
 VNET_DEVICE_CLASS (virtio_device_class) = {
   .name = "virtio",
   .tx_function = virtio_interface_tx,
   .format_device_name = format_virtio_device_name,
   .format_device = format_virtio_device,
   .format_tx_trace = format_virtio_tx_trace,
   .tx_function_n_errors = TAP_TX_N_ERROR,
   .tx_function_error_strings = virtio_tx_func_error_strings,
   .rx_redirect_to_node = virtio_set_interface_next_node,
   .clear_counters = virtio_clear_hw_interface_counters,
   .admin_up_down_function = virtio_interface_admin_up_down,
   .subif_add_del_function = virtio_subif_add_del_function,
   .rx_mode_change_function = virtio_interface_rx_mode_change,
 };

 VLIB_DEVICE_TX_FUNCTION_MULTIARCH(virtio_device_class,
 				  virtio_interface_tx)
 /* *INDENT-ON* */

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	*------------------------------------------------------------------
	* Copyright (c) 2016 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*------------------------------------------------------------------
	*/

	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <linux/virtio_net.h>
	#include <linux/vhost.h>

	#include <vlib/vlib.h>
	#include <vlib/unix/unix.h>
	#include <vnet/ethernet/ethernet.h>
	#include <vnet/ip/ip4_packet.h>
	#include <vnet/ip/ip6_packet.h>
	#include <vnet/devices/virtio/virtio.h>

	#define foreach_virtio_tx_func_error \
	_(NO_FREE_SLOTS, "no free tx slots") \
	_(TRUNC_PACKET, "packet > buffer size -- truncated in tx ring") \
	_(PENDING_MSGS, "pending msgs in tx ring") \
	_(NO_TX_QUEUES, "no tx queues")

	typedef enum
	{
	#define _(f,s) TAP_TX_ERROR_##f,
	foreach_virtio_tx_func_error
	#undef _
	TAP_TX_N_ERROR,
	} virtio_tx_func_error_t;

	static char *virtio_tx_func_error_strings[] = {
	#define _(n,s) s,
	foreach_virtio_tx_func_error
	#undef _
	};

	u8 *
	format_virtio_device_name (u8 * s, va_list * args)
	{
	u32 dev_instance = va_arg (*args, u32);
	virtio_main_t *mm = &virtio_main;
	virtio_if_t *vif = pool_elt_at_index (mm->interfaces, dev_instance);

	if (vif->type == VIRTIO_IF_TYPE_TAP)
	{
	s = format (s, "tap%u", vif->id);
	}
	else
	s = format (s, "virtio%lu", vif->dev_instance);

	return s;
	}

	static u8 *
	format_virtio_device (u8 * s, va_list * args)
	{
	u32 dev_instance = va_arg (*args, u32);
	int verbose = va_arg (*args, int);
	u32 indent = format_get_indent (s);

	s = format (s, "VIRTIO interface");
	if (verbose)
	{
	s = format (s, "\n%U instance %u", format_white_space, indent + 2,
	dev_instance);
	}
	return s;
	}

	static u8 *
	format_virtio_tx_trace (u8 * s, va_list * args)
	{
	s = format (s, "Unimplemented...");
	return s;
	}

	inline void
	virtio_free_used_desc (vlib_main_t * vm, virtio_vring_t * vring)
	{
	u16 used = vring->desc_in_use;
	u16 sz = vring->size;
	u16 mask = sz - 1;
	u16 last = vring->last_used_idx;
	u16 n_left = vring->used->idx - last;

	if (n_left == 0)
	return;

	while (n_left)
	{
	struct vring_used_elem *e = &vring->used->ring[last & mask];
	u16 slot = e->id;
	struct vring_desc *d = &vring->desc[slot];

	if (PREDICT_FALSE (d->flags & VRING_DESC_F_INDIRECT))
	{
	d = uword_to_pointer (d->addr, struct vring_desc *);
	vec_free (d);
	}

	vlib_buffer_free (vm, &vring->buffers[slot], 1);
	used--;
	last++;
	n_left--;
	}
	vring->desc_in_use = used;
	vring->last_used_idx = last;
	}

	static_always_inline u16
	add_buffer_to_slot (vlib_main_t * vm, virtio_vring_t * vring, u32 bi,
	u16 avail, u16 next, u16 mask)
	{
	u16 n_added = 0;
	const int hdr_sz = sizeof (struct virtio_net_hdr_v1);
	struct vring_desc *d;
	d = &vring->desc[next];
	vlib_buffer_t *b = vlib_get_buffer (vm, bi);
	struct virtio_net_hdr_v1 *hdr = vlib_buffer_get_current (b) - hdr_sz;

	clib_memset (hdr, 0, hdr_sz);

	if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
	{
	d->addr = pointer_to_uword (vlib_buffer_get_current (b)) - hdr_sz;
	d->len = b->current_length + hdr_sz;
	d->flags = 0;
	}
	else
	{
	struct vring_desc id, descs = 0;

	/* first buffer in chain */
	vec_add2_aligned (descs, id, 1, CLIB_CACHE_LINE_BYTES);
	id->addr = pointer_to_uword (vlib_buffer_get_current (b)) - hdr_sz;
	id->len = b->current_length + hdr_sz;

	while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
	{
	id->flags = VRING_DESC_F_NEXT;
	id->next = vec_len (descs);
	vec_add2_aligned (descs, id, 1, CLIB_CACHE_LINE_BYTES);
	b = vlib_get_buffer (vm, b->next_buffer);
	id->addr = pointer_to_uword (vlib_buffer_get_current (b));
	id->len = b->current_length;
	}

	d->addr = pointer_to_uword (descs);
	d->len = vec_len (descs) * sizeof (struct vring_desc);
	d->flags = VRING_DESC_F_INDIRECT;
	}
	vring->buffers[next] = bi;
	vring->avail->ring[avail & mask] = next;
	n_added++;
	return n_added;
	}


	static_always_inline uword
	virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
	vlib_frame_t * frame, virtio_if_t * vif)
	{
	u8 qid = 0;
	u16 n_left = frame->n_vectors;
	virtio_vring_t *vring = vec_elt_at_index (vif->vrings, (qid << 1) + 1);
	u16 used, next, avail;
	u16 sz = vring->size;
	u16 mask = sz - 1;
	u32 *buffers = vlib_frame_args (frame);

	clib_spinlock_lock_if_init (&vif->lockp);

	/* free consumed buffers */
	virtio_free_used_desc (vm, vring);

	used = vring->desc_in_use;
	next = vring->desc_next;
	avail = vring->avail->idx;

	while (n_left && used < sz)
	{
	u16 n_added;
	n_added = add_buffer_to_slot (vm, vring, buffers[0], avail, next, mask);
	avail += n_added;
	next = (next + n_added) & mask;
	used += n_added;
	buffers++;
	n_left--;
	}

	if (n_left != frame->n_vectors)
	{
	CLIB_MEMORY_STORE_BARRIER ();
	vring->avail->idx = avail;
	vring->desc_next = next;
	vring->desc_in_use = used;
	if ((vring->used->flags & VIRTIO_RING_FLAG_MASK_INT) == 0)
	{
	u64 x = 1;
	CLIB_UNUSED (int r) = write (vring->kick_fd, &x, sizeof (x));
	}
	}


	if (n_left)
	{
	vlib_error_count (vm, node->node_index, TAP_TX_ERROR_NO_FREE_SLOTS,
	n_left);
	vlib_buffer_free (vm, buffers, n_left);
	}

	clib_spinlock_unlock_if_init (&vif->lockp);

	return frame->n_vectors - n_left;
	}

	static uword
	virtio_interface_tx (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * frame)
	{
	virtio_main_t *nm = &virtio_main;
	vnet_interface_output_runtime_t rund = (void ) node->runtime_data;
	virtio_if_t *vif = pool_elt_at_index (nm->interfaces, rund->dev_instance);

	return virtio_interface_tx_inline (vm, node, frame, vif);
	}

	static void
	virtio_set_interface_next_node (vnet_main_t * vnm, u32 hw_if_index,
	u32 node_index)
	{
	virtio_main_t *apm = &virtio_main;
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
	virtio_if_t *vif = pool_elt_at_index (apm->interfaces, hw->dev_instance);

	/* Shut off redirection */
	if (node_index == ~0)
	{
	vif->per_interface_next_index = node_index;
	return;
	}

	vif->per_interface_next_index =
	vlib_node_add_next (vlib_get_main (), virtio_input_node.index,
	node_index);
	}

	static void
	virtio_clear_hw_interface_counters (u32 instance)
	{
	/* Nothing for now */
	}

	static clib_error_t *
	virtio_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index, u32 qid,
	vnet_hw_interface_rx_mode mode)
	{
	virtio_main_t *mm = &virtio_main;
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
	virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
	virtio_vring_t *vring = vec_elt_at_index (vif->vrings, qid);

	if (mode == VNET_HW_INTERFACE_RX_MODE_POLLING)
	vring->avail->flags \|= VIRTIO_RING_FLAG_MASK_INT;
	else
	vring->avail->flags &= ~VIRTIO_RING_FLAG_MASK_INT;

	return 0;
	}

	static clib_error_t *
	virtio_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
	{
	virtio_main_t *mm = &virtio_main;
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
	virtio_if_t *vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);

	if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
	vif->flags \|= VIRTIO_IF_FLAG_ADMIN_UP;
	else
	vif->flags &= ~VIRTIO_IF_FLAG_ADMIN_UP;

	return 0;
	}

	static clib_error_t *
	virtio_subif_add_del_function (vnet_main_t * vnm,
	u32 hw_if_index,
	struct vnet_sw_interface_t *st, int is_add)
	{
	/* Nothing for now */
	return 0;
	}

	/* INDENT-OFF */
	VNET_DEVICE_CLASS (virtio_device_class) = {
	.name = "virtio",
	.tx_function = virtio_interface_tx,
	.format_device_name = format_virtio_device_name,
	.format_device = format_virtio_device,
	.format_tx_trace = format_virtio_tx_trace,
	.tx_function_n_errors = TAP_TX_N_ERROR,
	.tx_function_error_strings = virtio_tx_func_error_strings,
	.rx_redirect_to_node = virtio_set_interface_next_node,
	.clear_counters = virtio_clear_hw_interface_counters,
	.admin_up_down_function = virtio_interface_admin_up_down,
	.subif_add_del_function = virtio_subif_add_del_function,
	.rx_mode_change_function = virtio_interface_rx_mode_change,
	};

	VLIB_DEVICE_TX_FUNCTION_MULTIARCH(virtio_device_class,
	virtio_interface_tx)
	/* INDENT-ON */

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/