[U-Boot] [PATCH 05/27] virtio: Add net driver support

[Joe Hershberger <joe.hershberger@ni.com>]

On Sun, Sep 23, 2018 at 8:48 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> From: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
>
> This adds virtio net device driver support.
>
> Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
> Signed-off-by: Bin Meng <bmeng.cn@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@iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn@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@iki.fi>
> + * Copyright (C) 2018, Bin Meng <bmeng.cn@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
>
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> https://lists.denx.de/listinfo/u-boot