Xen netfront driver. More...

#include <ipxe/xen.h>
#include <xen/io/netif.h>

Data Structures
struct	netfront_ring
	A netfront descriptor ring. More...
struct	netfront_nic
	A netfront NIC. More...

Macros
#define	NETFRONT_NUM_TX_DESC 16
	Number of transmit ring entries.
#define	NETFRONT_NUM_RX_DESC 32
	Number of receive ring entries.
#define	NETFRONT_RX_FILL 18
	Receive ring fill level.
#define	tx_sring tx.sring.tx
	Transmit shared ring field.
#define	rx_sring rx.sring.rx
	Receive shared ring field.

Enumerations
enum	netfront_ref_index { NETFRONT_REF_TX_RING = 0 , NETFRONT_REF_TX_BASE , NETFRONT_REF_RX_RING = ( NETFRONT_REF_TX_BASE + NETFRONT_NUM_TX_DESC ) , NETFRONT_REF_RX_BASE , NETFRONT_REF_COUNT = ( NETFRONT_REF_RX_BASE + NETFRONT_NUM_RX_DESC ) }
	Grant reference indices. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static	__attribute__ ((always_inline)) void netfront_init_ring(struct netfront_ring *ring
	Initialise descriptor ring.

Variables
static const char *	ref_key
static const char grant_ref_t	ref = ref
static const char grant_ref_t unsigned int	count = count
static const char grant_ref_t unsigned int struct io_buffer **	iobufs = iobufs
static const char grant_ref_t unsigned int struct io_buffer grant_ref_t *	refs = refs
static const char grant_ref_t unsigned int struct io_buffer grant_ref_t uint8_t *	ids

Detailed Description

Xen netfront driver.

Definition in file netfront.h.

Macro Definition Documentation

◆ NETFRONT_NUM_TX_DESC

#define NETFRONT_NUM_TX_DESC 16

Number of transmit ring entries.

Definition at line 17 of file netfront.h.

Referenced by netfront_probe().

◆ NETFRONT_NUM_RX_DESC

#define NETFRONT_NUM_RX_DESC 32

Number of receive ring entries.

Definition at line 20 of file netfront.h.

Referenced by netfront_probe().

◆ NETFRONT_RX_FILL

#define NETFRONT_RX_FILL 18

Receive ring fill level.

The xen-netback driver from kernels 3.18 to 4.2 inclusive have a bug (CA-163395) which prevents packet reception if fewer than 18 receive descriptors are available. This was fixed in upstream kernel commit d5d4852 ("xen-netback: require fewer guest Rx slots when not using GSO").

We provide 18 receive descriptors to avoid unpleasant silent failures on these kernel versions.

Definition at line 33 of file netfront.h.

Referenced by netfront_refill_rx().

◆ tx_sring

#define tx_sring tx.sring.tx

Transmit shared ring field.

Definition at line 193 of file netfront.h.

◆ rx_sring

#define rx_sring rx.sring.rx

Receive shared ring field.

Definition at line 196 of file netfront.h.

Enumeration Type Documentation

◆ netfront_ref_index

enum netfront_ref_index

Grant reference indices.

Enumerator
NETFRONT_REF_TX_RING	Transmit ring grant reference index.
NETFRONT_REF_TX_BASE	Transmit descriptor grant reference base index.
NETFRONT_REF_RX_RING	Receive ring grant reference index.
NETFRONT_REF_RX_BASE	Receive descriptor grant reference base index.
NETFRONT_REF_COUNT	Total number of grant references required.

Definition at line 36 of file netfront.h.

                        {
        /** Transmit ring grant reference index */
        NETFRONT_REF_TX_RING = 0,
        /** Transmit descriptor grant reference base index */
        NETFRONT_REF_TX_BASE,
        /** Receive ring grant reference index */
        NETFRONT_REF_RX_RING = ( NETFRONT_REF_TX_BASE + NETFRONT_NUM_TX_DESC ),
        /** Receive descriptor grant reference base index */
        NETFRONT_REF_RX_BASE,
        /** Total number of grant references required */
        NETFRONT_REF_COUNT = ( NETFRONT_REF_RX_BASE + NETFRONT_NUM_RX_DESC )
};

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )

◆ FILE_SECBOOT()

FILE_SECBOOT ( PERMITTED )

◆ attribute()

__attribute__ ( (always_inline) )

inlinestatic

Initialise descriptor ring.

Check whether or not descriptor ring is empty.

Check whether or not descriptor ring is full.

Calculate descriptor ring remaining space.

Calculate descriptor ring fill level.

Parameters

ring	Descriptor ring
ref_key	Shared ring grant reference key
ref	Shared ring grant reference
count	Maxium number of used descriptors
iobufs	I/O buffers
refs	I/O buffer grant references
ids	Buffer IDs
ring	Descriptor ring
fill	Fill level
ring	Descriptor ring
space	Number of unused entries
ring	Descriptor ring
is_full	Ring is full
ring	Descriptor ring
is_empty	Ring is empty

Definition at line 111 of file netfront.h.

                                                  {
        unsigned int fill_level;
 
        fill_level = ( ring->id_prod - ring->id_cons );
        assert ( fill_level <= ring->count );
        return fill_level;
}

References assert, count, netfront_ring::id_cons, and netfront_ring::id_prod.

Variable Documentation

◆ ref_key

const char* ref_key

Definition at line 92 of file netfront.h.

◆ ref

grant_ref_t ref = ref

Definition at line 93 of file netfront.h.

Referenced by netfront_push(), xengrant_alloc(), and xengrant_free().

◆ count

ring count = count

Definition at line 93 of file netfront.h.

◆ iobufs

ring iobufs = iobufs

Definition at line 94 of file netfront.h.

◆ refs

ring refs = refs

Definition at line 94 of file netfront.h.

Referenced by xengrant_alloc(), and xengrant_free().

◆ ids

ring ids

Initial value:

{
 
        ring->ref_key = ref_key

Definition at line 95 of file netfront.h.

Data Structures

Macros

Enumerations

Functions

Variables