virtio: Add net driver support

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>
Reviewed-by: Simon Glass <sjg@chromium.org>

4 files changed, 494 insertions, 0 deletions

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 4f9a11b6ef..e20dd69395 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -29,4 +29,11 @@ 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 2e487854a2..b7764f161e 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 0000000000..5bb6a9fcc9
--- /dev/null
+++ b/drivers/virtio/virtio_net.c
@@ -0,0 +1,218 @@
+// 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_types.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 const u32 feature[] = {
+	VIRTIO_NET_F_MAC
+};
+
+static const 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];
+			virtqueue_add(priv->rx_vq, sgs, 0, 1);
+		}
+
+		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;
+	}
+
+	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);
+
+	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;
+
+	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,
+	.remove = virtio_reset,
+	.ops	= &virtio_net_ops,
+	.priv_auto_alloc_size = sizeof(struct virtio_net_priv),
+	.platdata_auto_alloc_size = sizeof(struct eth_pdata),
+	.flags	= DM_FLAG_ACTIVE_DMA,
+};
diff --git a/drivers/virtio/virtio_net.h b/drivers/virtio/virtio_net.h
new file mode 100644
index 0000000000..c92bae5269
--- /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 */