freebsd-skq/usr.sbin/bhyve/net_backends.h
John Baldwin 621b509048 Refactor configuration management in bhyve.
Replace the existing ad-hoc configuration via various global variables
with a small database of key-value pairs.  The database supports
heirarchical keys using a MIB-like syntax to name the path to a given
key.  Values are always stored as strings.  The API used to manage
configuation values does include wrappers to handling boolean values.
Other values use non-string types require parsing by consumers.

The configuration values are stored in a tree using nvlists.  Leaf
nodes hold string values.  Configuration values are permitted to
reference other configuration values using '%(name)'.  This permits
constructing template configurations.

All existing command line arguments now set configuration values.  For
devices, the "-s" option parses its option argument to generate a list
of key-value pairs for the given device.

A new '-o' command line option permits setting an individual
configuration variable.  The key name is always given as a full path
of dot-separated components.

A new '-k' command line option parses a simple configuration file.
This configuration file holds a flat list of 'key=value' lines where
the 'key' is the full path of a configuration variable.  Lines
starting with a '#' are comments.

In general, bhyve starts by parsing command line options in sequence
and applying those settings to configuration values.  Once this is
complete, bhyve then begins initializing its state based on the
configuration values.  This means that subsequent configuration
options or files may override or supplement previously given settings.

A special 'config.dump' configuration value can be set to true to help
debug configuration issues.  When this value is set, bhyve will print
out the configuration variables as a flat list of 'key=value' lines.

Most command line argments map to a single configuration variable,
e.g.  '-w' sets the 'x86.strictmsr' value to false.  A few command
line arguments have less obvious effects:

- Multiple '-p' options append their values (as a comma-seperated
  list) to "vcpu.N.cpuset" values (where N is a decimal vcpu number).

- For '-s' options, a pci.<bus>.<slot>.<function> node is created.
  The first argument to '-s' (the device type) is used as the value of
  a "device" variable.  Additional comma-separated arguments are then
  parsed into 'key=value' pairs and used to set additional variables
  under the device node.  A PCI device emulation driver can provide
  its own hook to override the parsing of the additonal '-s' arguments
  after the device type.

  After the configuration phase as completed, the init_pci hook
  then walks the "pci.<bus>.<slot>.<func>" nodes.  It uses the
  "device" value to find the device model to use.  The device
  model's init routine is passed a reference to its nvlist node
  in the configuration tree which it can query for specific
  variables.

  The result is that a lot of the string parsing is removed from
  the device models and centralized.  In addition, adding a new
  variable just requires teaching the model to look for the new
  variable.

- For '-l' options, a similar model is used where the string is
  parsed into values that are later read during initialization.
  One key note here is that the serial ports use the commonly
  used lowercase names from existing documentation and examples
  (e.g. "lpc.com1") instead of the uppercase names previously
  used internally in bhyve.

Reviewed by:	grehan
MFC after:	3 months
Differential Revision:	https://reviews.freebsd.org/D26035
2021-03-18 16:30:26 -07:00

97 lines
4.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2019 Vincenzo Maffione <vmaffione@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef __NET_BACKENDS_H__
#define __NET_BACKENDS_H__
#include <stdint.h>
/* Opaque type representing a network backend. */
typedef struct net_backend net_backend_t;
/* Interface between network frontends and the network backends. */
typedef void (*net_be_rxeof_t)(int, enum ev_type, void *param);
int netbe_init(net_backend_t **be, nvlist_t *nvl, net_be_rxeof_t cb,
void *param);
int netbe_legacy_config(nvlist_t *nvl, const char *opts);
void netbe_cleanup(net_backend_t *be);
uint64_t netbe_get_cap(net_backend_t *be);
int netbe_set_cap(net_backend_t *be, uint64_t cap,
unsigned vnet_hdr_len);
size_t netbe_get_vnet_hdr_len(net_backend_t *be);
ssize_t netbe_send(net_backend_t *be, const struct iovec *iov, int iovcnt);
ssize_t netbe_peek_recvlen(net_backend_t *be);
ssize_t netbe_recv(net_backend_t *be, const struct iovec *iov, int iovcnt);
ssize_t netbe_rx_discard(net_backend_t *be);
void netbe_rx_disable(net_backend_t *be);
void netbe_rx_enable(net_backend_t *be);
/*
* Network device capabilities taken from the VirtIO standard.
* Despite the name, these capabilities can be used by different frontents
* (virtio-net, ptnet) and supported by different backends (netmap, tap, ...).
*/
#define VIRTIO_NET_F_CSUM (1 << 0) /* host handles partial cksum */
#define VIRTIO_NET_F_GUEST_CSUM (1 << 1) /* guest handles partial cksum */
#define VIRTIO_NET_F_MTU (1 << 3) /* initial MTU advice */
#define VIRTIO_NET_F_MAC (1 << 5) /* host supplies MAC */
#define VIRTIO_NET_F_GSO_DEPREC (1 << 6) /* deprecated: host handles GSO */
#define VIRTIO_NET_F_GUEST_TSO4 (1 << 7) /* guest can rcv TSOv4 */
#define VIRTIO_NET_F_GUEST_TSO6 (1 << 8) /* guest can rcv TSOv6 */
#define VIRTIO_NET_F_GUEST_ECN (1 << 9) /* guest can rcv TSO with ECN */
#define VIRTIO_NET_F_GUEST_UFO (1 << 10) /* guest can rcv UFO */
#define VIRTIO_NET_F_HOST_TSO4 (1 << 11) /* host can rcv TSOv4 */
#define VIRTIO_NET_F_HOST_TSO6 (1 << 12) /* host can rcv TSOv6 */
#define VIRTIO_NET_F_HOST_ECN (1 << 13) /* host can rcv TSO with ECN */
#define VIRTIO_NET_F_HOST_UFO (1 << 14) /* host can rcv UFO */
#define VIRTIO_NET_F_MRG_RXBUF (1 << 15) /* host can merge RX buffers */
#define VIRTIO_NET_F_STATUS (1 << 16) /* config status field available */
#define VIRTIO_NET_F_CTRL_VQ (1 << 17) /* control channel available */
#define VIRTIO_NET_F_CTRL_RX (1 << 18) /* control channel RX mode support */
#define VIRTIO_NET_F_CTRL_VLAN (1 << 19) /* control channel VLAN filtering */
#define VIRTIO_NET_F_GUEST_ANNOUNCE \
(1 << 21) /* guest can send gratuitous pkts */
#define VIRTIO_NET_F_MQ (1 << 22) /* host supports multiple VQ pairs */
/*
* Fixed network header size
*/
struct virtio_net_rxhdr {
uint8_t vrh_flags;
uint8_t vrh_gso_type;
uint16_t vrh_hdr_len;
uint16_t vrh_gso_size;
uint16_t vrh_csum_start;
uint16_t vrh_csum_offset;
uint16_t vrh_bufs;
} __packed;
#endif /* __NET_BACKENDS_H__ */