[U-Boot] [PATCH 05/27] virtio: Add net driver support
Joe Hershberger
joe.hershberger at ni.com
Mon Oct 22 23:15:57 UTC 2018
On Sun, Sep 23, 2018 at 8:48 AM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> From: Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
>
> This adds virtio net device driver support.
>
> Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>
> drivers/virtio/Kconfig | 7 ++
> drivers/virtio/Makefile | 1 +
> drivers/virtio/virtio_net.c | 215 +++++++++++++++++++++++++++++++++++
> drivers/virtio/virtio_net.h | 268 ++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 491 insertions(+)
> create mode 100644 drivers/virtio/virtio_net.c
> create mode 100644 drivers/virtio/virtio_net.h
>
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 60cfaf8..ceea03a 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -18,4 +18,11 @@ config VIRTIO_MMIO
> This driver provides support for memory mapped virtio
> platform device driver.
>
> +config VIRTIO_NET
> + bool "virtio net driver"
> + depends on VIRTIO
> + help
> + This is the virtual net driver for virtio. It can be used with
> + QEMU based targets.
> +
> endmenu
> diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
> index 2e48785..b7764f1 100644
> --- a/drivers/virtio/Makefile
> +++ b/drivers/virtio/Makefile
> @@ -5,3 +5,4 @@
>
> obj-y += virtio-uclass.o virtio_ring.o
> obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
> +obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
> diff --git a/drivers/virtio/virtio_net.c b/drivers/virtio/virtio_net.c
> new file mode 100644
> index 0000000..1ab1513
> --- /dev/null
> +++ b/drivers/virtio/virtio_net.c
> @@ -0,0 +1,215 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <net.h>
> +#include <virtio.h>
> +#include <virtio_ring.h>
> +#include "virtio_net.h"
> +
> +/* Amount of buffers to keep in the RX virtqueue */
> +#define VIRTIO_NET_NUM_RX_BUFS 32
> +
> +/*
> + * This value comes from the VirtIO spec: 1500 for maximum packet size,
> + * 14 for the Ethernet header, 12 for virtio_net_hdr. In total 1526 bytes.
> + */
> +#define VIRTIO_NET_RX_BUF_SIZE 1526
> +
> +struct virtio_net_priv {
> + union {
> + struct virtqueue *vqs[2];
> + struct {
> + struct virtqueue *rx_vq;
> + struct virtqueue *tx_vq;
> + };
> + };
> +
> + char rx_buff[VIRTIO_NET_NUM_RX_BUFS][VIRTIO_NET_RX_BUF_SIZE];
> + bool rx_running;
> +};
> +
> +/*
> + * For simplicity, the driver only negotiates the VIRTIO_NET_F_MAC feature.
> + * For the VIRTIO_NET_F_STATUS feature, we don't negotiate it, hence per spec
> + * we should assume the link is always active.
> + */
> +static u32 feature[] = {
> + VIRTIO_NET_F_MAC
> +};
> +
> +static u32 feature_legacy[] = {
> + VIRTIO_NET_F_MAC
> +};
> +
> +static int virtio_net_start(struct udevice *dev)
> +{
> + struct virtio_net_priv *priv = dev_get_priv(dev);
> + struct virtio_sg sg;
> + struct virtio_sg *sgs[] = { &sg };
> + int i;
> +
> + if (!priv->rx_running) {
> + /* receive buffer length is always 1526 */
> + sg.length = VIRTIO_NET_RX_BUF_SIZE;
> +
> + /* setup the receive buffer address */
> + for (i = 0; i < VIRTIO_NET_NUM_RX_BUFS; i++) {
> + sg.addr = priv->rx_buff[i];
It's kinda peculiar the way this is used in place multiple times.
> + virtqueue_add(priv->rx_vq, sgs, 0, 1);
I hope this copies the structure since it is stack memory and modified
on each iteration. Probably justifies a comment.
> + }
> +
> + virtqueue_kick(priv->rx_vq);
> +
> + /* setup the receive queue only once */
> + priv->rx_running = true;
> + }
> +
> + return 0;
> +}
> +
> +static int virtio_net_send(struct udevice *dev, void *packet, int length)
> +{
> + struct virtio_net_priv *priv = dev_get_priv(dev);
> + struct virtio_net_hdr hdr;
> + struct virtio_sg hdr_sg = { &hdr, sizeof(hdr) };
> + struct virtio_sg data_sg = { packet, length };
> + struct virtio_sg *sgs[] = { &hdr_sg, &data_sg };
> + int ret;
> +
> + memset(&hdr, 0, sizeof(struct virtio_net_hdr));
> +
> + ret = virtqueue_add(priv->tx_vq, sgs, 2, 0);
> + if (ret)
> + return ret;
> +
> + virtqueue_kick(priv->tx_vq);
> +
> + while (1) {
> + if (virtqueue_get_buf(priv->tx_vq, NULL))
> + break;
Potential infinite loop?
> + }
> +
> + return 0;
> +}
> +
> +static int virtio_net_recv(struct udevice *dev, int flags, uchar **packetp)
> +{
> + struct virtio_net_priv *priv = dev_get_priv(dev);
> + unsigned int len;
> + void *buf;
> +
> + buf = virtqueue_get_buf(priv->rx_vq, &len);
> + if (!buf)
> + return -EAGAIN;
> +
> + *packetp = buf + sizeof(struct virtio_net_hdr);
> + return len - sizeof(struct virtio_net_hdr);
> +}
> +
> +static int virtio_net_free_pkt(struct udevice *dev, uchar *packet, int length)
> +{
> + struct virtio_net_priv *priv = dev_get_priv(dev);
> + void *buf = packet - sizeof(struct virtio_net_hdr);
> + struct virtio_sg sg = { buf, VIRTIO_NET_RX_BUF_SIZE };
> + struct virtio_sg *sgs[] = { &sg };
> +
> + /* Put the buffer back to the rx ring */
> + virtqueue_add(priv->rx_vq, sgs, 0, 1);
So does that mean that the virtqueue_get_buf() function removed it?
> +
> + return 0;
> +}
> +
> +static void virtio_net_stop(struct udevice *dev)
> +{
> + /*
> + * There is no way to stop the queue from running, unless we issue
> + * a reset to the virtio device, and re-do the queue initialization
> + * from the beginning.
> + */
> +}
> +
> +static int virtio_net_write_hwaddr(struct udevice *dev)
> +{
> + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
> + struct eth_pdata *pdata = dev_get_platdata(dev);
> + int i;
> +
> + /*
> + * v1.0 compliant device's MAC address is set through control channel,
> + * which we don't support for now.
> + */
> + if (!uc_priv->legacy)
> + return -ENOSYS;
> +
> + for (i = 0; i < sizeof(pdata->enetaddr); i++) {
> + virtio_cwrite8(dev,
> + offsetof(struct virtio_net_config, mac) + i,
> + pdata->enetaddr[i]);
> + }
> +
> + return 0;
> +}
> +
> +static int virtio_net_read_rom_hwaddr(struct udevice *dev)
> +{
> + struct eth_pdata *pdata = dev_get_platdata(dev);
> +
> + if (!pdata)
> + return -ENOSYS;
> +
> + if (virtio_has_feature(dev, VIRTIO_NET_F_MAC)) {
> + virtio_cread_bytes(dev,
> + offsetof(struct virtio_net_config, mac),
> + pdata->enetaddr, sizeof(pdata->enetaddr));
> + }
> +
> + return 0;
> +}
> +
> +static int virtio_net_bind(struct udevice *dev)
> +{
> + struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(dev->parent);
> +
> + /* Indicate what driver features we support */
> + virtio_driver_features_init(uc_priv, feature, ARRAY_SIZE(feature),
> + feature_legacy, ARRAY_SIZE(feature_legacy));
> +
> + return 0;
> +}
> +
> +static int virtio_net_probe(struct udevice *dev)
> +{
> + struct virtio_net_priv *priv = dev_get_priv(dev);
> + int ret;
> +
Seems like priv->rx_running should be initialized to false here.
> + ret = virtio_find_vqs(dev, 2, priv->vqs);
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static const struct eth_ops virtio_net_ops = {
> + .start = virtio_net_start,
> + .send = virtio_net_send,
> + .recv = virtio_net_recv,
> + .free_pkt = virtio_net_free_pkt,
> + .stop = virtio_net_stop,
> + .write_hwaddr = virtio_net_write_hwaddr,
> + .read_rom_hwaddr = virtio_net_read_rom_hwaddr,
> +};
> +
> +U_BOOT_DRIVER(virtio_net) = {
> + .name = VIRTIO_NET_DRV_NAME,
> + .id = UCLASS_ETH,
> + .bind = virtio_net_bind,
> + .probe = virtio_net_probe,
> + .ops = &virtio_net_ops,
> + .priv_auto_alloc_size = sizeof(struct virtio_net_priv),
> + .platdata_auto_alloc_size = sizeof(struct eth_pdata),
> +};
> diff --git a/drivers/virtio/virtio_net.h b/drivers/virtio/virtio_net.h
> new file mode 100644
> index 0000000..c92bae5
> --- /dev/null
> +++ b/drivers/virtio/virtio_net.h
> @@ -0,0 +1,268 @@
> +/* SPDX-License-Identifier: BSD-3-Clause */
> +/*
> + * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + *
> + * From Linux kernel include/uapi/linux/virtio_net.h
> + */
> +
> +#ifndef _LINUX_VIRTIO_NET_H
> +#define _LINUX_VIRTIO_NET_H
> +
> +/* TODO: needs to be removed! */
> +#define ETH_ALEN 6
> +
> +/* The feature bitmap for virtio net */
> +
> +/* Host handles pkts w/ partial csum */
> +#define VIRTIO_NET_F_CSUM 0
> +/* Guest handles pkts w/ partial csum */
> +#define VIRTIO_NET_F_GUEST_CSUM 1
> +/* Dynamic offload configuration */
> +#define VIRTIO_NET_F_CTRL_GUEST_OFFLOADS 2
> +/* Initial MTU advice */
> +#define VIRTIO_NET_F_MTU 3
> +/* Host has given MAC address */
> +#define VIRTIO_NET_F_MAC 5
> +/* Guest can handle TSOv4 in */
> +#define VIRTIO_NET_F_GUEST_TSO4 7
> +/* Guest can handle TSOv6 in */
> +#define VIRTIO_NET_F_GUEST_TSO6 8
> +/* Guest can handle TSO[6] w/ ECN in */
> +#define VIRTIO_NET_F_GUEST_ECN 9
> +/* Guest can handle UFO in */
> +#define VIRTIO_NET_F_GUEST_UFO 10
> +/* Host can handle TSOv4 in */
> +#define VIRTIO_NET_F_HOST_TSO4 11
> +/* Host can handle TSOv6 in */
> +#define VIRTIO_NET_F_HOST_TSO6 12
> +/* Host can handle TSO[6] w/ ECN in */
> +#define VIRTIO_NET_F_HOST_ECN 13
> +/* Host can handle UFO in */
> +#define VIRTIO_NET_F_HOST_UFO 14
> +/* Host can merge receive buffers */
> +#define VIRTIO_NET_F_MRG_RXBUF 15
> +/* virtio_net_config.status available */
> +#define VIRTIO_NET_F_STATUS 16
> +/* Control channel available */
> +#define VIRTIO_NET_F_CTRL_VQ 17
> +/* Control channel RX mode support */
> +#define VIRTIO_NET_F_CTRL_RX 18
> +/* Control channel VLAN filtering */
> +#define VIRTIO_NET_F_CTRL_VLAN 19
> +/* Extra RX mode control support */
> +#define VIRTIO_NET_F_CTRL_RX_EXTRA 20
> +/* Guest can announce device on the network */
> +#define VIRTIO_NET_F_GUEST_ANNOUNCE 21
> +/* Device supports receive flow steering */
> +#define VIRTIO_NET_F_MQ 22
> +/* Set MAC address */
> +#define VIRTIO_NET_F_CTRL_MAC_ADDR 23
> +/* Device set linkspeed and duplex */
> +#define VIRTIO_NET_F_SPEED_DUPLEX 63
> +
> +#ifndef VIRTIO_NET_NO_LEGACY
> +/* Host handles pkts w/ any GSO type */
> +#define VIRTIO_NET_F_GSO 6
> +#endif /* VIRTIO_NET_NO_LEGACY */
> +
> +#define VIRTIO_NET_S_LINK_UP 1 /* Link is up */
> +#define VIRTIO_NET_S_ANNOUNCE 2 /* Announcement is needed */
> +
> +struct __packed virtio_net_config {
> + /* The config defining mac address (if VIRTIO_NET_F_MAC) */
> + __u8 mac[ETH_ALEN];
> + /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
> + __u16 status;
> + /*
> + * Maximum number of each of transmit and receive queues;
> + * see VIRTIO_NET_F_MQ and VIRTIO_NET_CTRL_MQ.
> + * Legal values are between 1 and 0x8000
> + */
> + __u16 max_virtqueue_pairs;
> + /* Default maximum transmit unit advice */
> + __u16 mtu;
> + /*
> + * speed, in units of 1Mb. All values 0 to INT_MAX are legal.
> + * Any other value stands for unknown.
> + */
> + __u32 speed;
> + /*
> + * 0x00 - half duplex
> + * 0x01 - full duplex
> + * Any other value stands for unknown.
> + */
> + __u8 duplex;
> +};
> +
> +/*
> + * This header comes first in the scatter-gather list. If you don't
> + * specify GSO or CSUM features, you can simply ignore the header.
> + *
> + * This is bitwise-equivalent to the legacy struct virtio_net_hdr_mrg_rxbuf,
> + * only flattened.
> + */
> +struct virtio_net_hdr_v1 {
> +#define VIRTIO_NET_HDR_F_NEEDS_CSUM 0x01 /* Use csum_start, csum_offset */
> +#define VIRTIO_NET_HDR_F_DATA_VALID 0x02 /* Csum is valid */
> + __u8 flags;
> +#define VIRTIO_NET_HDR_GSO_NONE 0x00 /* Not a GSO frame */
> +#define VIRTIO_NET_HDR_GSO_TCPV4 0x01 /* GSO frame, IPv4 TCP (TSO) */
> +#define VIRTIO_NET_HDR_GSO_UDP 0x03 /* GSO frame, IPv4 UDP (UFO) */
> +#define VIRTIO_NET_HDR_GSO_TCPV6 0x04 /* GSO frame, IPv6 TCP */
> +#define VIRTIO_NET_HDR_GSO_ECN 0x80 /* TCP has ECN set */
> + __u8 gso_type;
> + __virtio16 hdr_len; /* Ethernet + IP + tcp/udp hdrs */
> + __virtio16 gso_size; /* Bytes to append to hdr_len per frame */
> + __virtio16 csum_start; /* Position to start checksumming from */
> + __virtio16 csum_offset; /* Offset after that to place checksum */
> + __virtio16 num_buffers; /* Number of merged rx buffers */
> +};
> +
> +#ifndef VIRTIO_NET_NO_LEGACY
> +/*
> + * This header comes first in the scatter-gather list.
> + *
> + * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, it must
> + * be the first element of the scatter-gather list. If you don't
> + * specify GSO or CSUM features, you can simply ignore the header.
> + */
> +struct virtio_net_hdr {
> + /* See VIRTIO_NET_HDR_F_* */
> + __u8 flags;
> + /* See VIRTIO_NET_HDR_GSO_* */
> + __u8 gso_type;
> + __virtio16 hdr_len; /* Ethernet + IP + tcp/udp hdrs */
> + __virtio16 gso_size; /* Bytes to append to hdr_len per frame */
> + __virtio16 csum_start; /* Position to start checksumming from */
> + __virtio16 csum_offset; /* Offset after that to place checksum */
> +};
> +
> +/*
> + * This is the version of the header to use when the MRG_RXBUF
> + * feature has been negotiated.
> + */
> +struct virtio_net_hdr_mrg_rxbuf {
> + struct virtio_net_hdr hdr;
> + __virtio16 num_buffers; /* Number of merged rx buffers */
> +};
> +#endif /* ...VIRTIO_NET_NO_LEGACY */
> +
> +/*
> + * Control virtqueue data structures
> + *
> + * The control virtqueue expects a header in the first sg entry
> + * and an ack/status response in the last entry. Data for the
> + * command goes in between.
> + */
> +struct __packed virtio_net_ctrl_hdr {
> + __u8 class;
> + __u8 cmd;
> +};
> +
> +typedef __u8 virtio_net_ctrl_ack;
> +
> +#define VIRTIO_NET_OK 0
> +#define VIRTIO_NET_ERR 1
> +
> +/*
> + * Control the RX mode, ie. promisucous, allmulti, etc...
> + *
> + * All commands require an "out" sg entry containing a 1 byte state value,
> + * zero = disable, non-zero = enable.
> + *
> + * Commands 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
> + * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
> + */
> +#define VIRTIO_NET_CTRL_RX 0
> +#define VIRTIO_NET_CTRL_RX_PROMISC 0
> +#define VIRTIO_NET_CTRL_RX_ALLMULTI 1
> +#define VIRTIO_NET_CTRL_RX_ALLUNI 2
> +#define VIRTIO_NET_CTRL_RX_NOMULTI 3
> +#define VIRTIO_NET_CTRL_RX_NOUNI 4
> +#define VIRTIO_NET_CTRL_RX_NOBCAST 5
> +
> +/*
> + * Control the MAC
> + *
> + * The MAC filter table is managed by the hypervisor, the guest should assume
> + * the size is infinite. Filtering should be considered non-perfect, ie. based
> + * on hypervisor resources, the guest may received packets from sources not
> + * specified in the filter list.
> + *
> + * In addition to the class/cmd header, the TABLE_SET command requires two
> + * out scatterlists. Each contains a 4 byte count of entries followed by a
> + * concatenated byte stream of the ETH_ALEN MAC addresses. The first sg list
> + * contains unicast addresses, the second is for multicast. This functionality
> + * is present if the VIRTIO_NET_F_CTRL_RX feature is available.
> + *
> + * The ADDR_SET command requests one out scatterlist, it contains a 6 bytes MAC
> + * address. This functionality is present if the VIRTIO_NET_F_CTRL_MAC_ADDR
> + * feature is available.
> + */
> +struct __packed virtio_net_ctrl_mac {
> + __virtio32 entries;
> + __u8 macs[][ETH_ALEN];
> +};
> +
> +#define VIRTIO_NET_CTRL_MAC 1
> +#define VIRTIO_NET_CTRL_MAC_TABLE_SET 0
> +#define VIRTIO_NET_CTRL_MAC_ADDR_SET 1
> +
> +/*
> + * Control VLAN filtering
> + *
> + * The VLAN filter table is controlled via a simple ADD/DEL interface. VLAN IDs
> + * not added may be filterd by the hypervisor. Del is the opposite of add. Both
> + * commands expect an out entry containing a 2 byte VLAN ID. VLAN filterting is
> + * available with the VIRTIO_NET_F_CTRL_VLAN feature bit.
> + */
> +#define VIRTIO_NET_CTRL_VLAN 2
> +#define VIRTIO_NET_CTRL_VLAN_ADD 0
> +#define VIRTIO_NET_CTRL_VLAN_DEL 1
> +
> +/*
> + * Control link announce acknowledgment
> + *
> + * The command VIRTIO_NET_CTRL_ANNOUNCE_ACK is used to indicate that driver has
> + * recevied the notification; device would clear the VIRTIO_NET_S_ANNOUNCE bit
> + * in the status field after it receives this command.
> + */
> +#define VIRTIO_NET_CTRL_ANNOUNCE 3
> +#define VIRTIO_NET_CTRL_ANNOUNCE_ACK 0
> +
> +/*
> + * Control receive flow steering
> + *
> + * The command VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET enables receive flow steering,
> + * specifying the number of the transmit and receive queues that will be used.
> + * After the command is consumed and acked by the device, the device will not
> + * steer new packets on receive virtqueues other than specified nor read from
> + * transmit virtqueues other than specified. Accordingly, driver should not
> + * transmit new packets on virtqueues other than specified.
> + */
> +struct virtio_net_ctrl_mq {
> + __virtio16 virtqueue_pairs;
> +};
> +
> +#define VIRTIO_NET_CTRL_MQ 4
> +#define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET 0
> +#define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN 1
> +#define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX 0x8000
> +
> +/*
> + * Control network offloads
> + *
> + * Reconfigures the network offloads that guest can handle.
> + *
> + * Available with the VIRTIO_NET_F_CTRL_GUEST_OFFLOADS feature bit.
> + *
> + * Command data format matches the feature bit mask exactly.
> + *
> + * See VIRTIO_NET_F_GUEST_* for the list of offloads
> + * that can be enabled/disabled.
> + */
> +#define VIRTIO_NET_CTRL_GUEST_OFFLOADS 5
> +#define VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET 0
> +
> +#endif /* _LINUX_VIRTIO_NET_H */
> --
> 2.7.4
>
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