Thomas Huth | 00dde1e | 2017-07-12 14:49:52 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Virtio-net driver for the s390-ccw firmware |
| 3 | * |
| 4 | * Copyright 2017 Thomas Huth, Red Hat Inc. |
| 5 | * |
| 6 | * This code is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License as published by the |
| 8 | * Free Software Foundation; either version 2 of the License, or (at your |
| 9 | * option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <stdint.h> |
| 13 | #include <stdbool.h> |
| 14 | #include <stdio.h> |
| 15 | #include <stdlib.h> |
| 16 | #include <string.h> |
| 17 | #include <unistd.h> |
| 18 | #include <sys/socket.h> |
| 19 | #include <ethernet.h> |
| 20 | #include "s390-ccw.h" |
| 21 | #include "virtio.h" |
Janosch Frank | e70bc57 | 2020-06-24 03:52:16 -0400 | [diff] [blame] | 22 | #include "s390-time.h" |
Janosch Frank | 12ea90d | 2020-06-24 03:52:17 -0400 | [diff] [blame] | 23 | #include "helper.h" |
Thomas Huth | 00dde1e | 2017-07-12 14:49:52 +0200 | [diff] [blame] | 24 | |
| 25 | #ifndef DEBUG_VIRTIO_NET |
| 26 | #define DEBUG_VIRTIO_NET 0 |
| 27 | #endif |
| 28 | |
| 29 | #define VIRTIO_NET_F_MAC_BIT (1 << 5) |
| 30 | |
| 31 | #define VQ_RX 0 /* Receive queue */ |
| 32 | #define VQ_TX 1 /* Transmit queue */ |
| 33 | |
| 34 | struct VirtioNetHdr { |
| 35 | uint8_t flags; |
| 36 | uint8_t gso_type; |
| 37 | uint16_t hdr_len; |
| 38 | uint16_t gso_size; |
| 39 | uint16_t csum_start; |
| 40 | uint16_t csum_offset; |
| 41 | /*uint16_t num_buffers;*/ /* Only with VIRTIO_NET_F_MRG_RXBUF or VIRTIO1 */ |
| 42 | }; |
| 43 | typedef struct VirtioNetHdr VirtioNetHdr; |
| 44 | |
| 45 | static uint16_t rx_last_idx; /* Last index in receive queue "used" ring */ |
| 46 | |
| 47 | int virtio_net_init(void *mac_addr) |
| 48 | { |
| 49 | VDev *vdev = virtio_get_device(); |
| 50 | VRing *rxvq = &vdev->vrings[VQ_RX]; |
| 51 | void *buf; |
| 52 | int i; |
| 53 | |
| 54 | vdev->guest_features[0] = VIRTIO_NET_F_MAC_BIT; |
| 55 | virtio_setup_ccw(vdev); |
| 56 | |
| 57 | IPL_assert(vdev->guest_features[0] & VIRTIO_NET_F_MAC_BIT, |
| 58 | "virtio-net device does not support the MAC address feature"); |
| 59 | memcpy(mac_addr, vdev->config.net.mac, ETH_ALEN); |
| 60 | |
| 61 | for (i = 0; i < 64; i++) { |
| 62 | buf = malloc(ETH_MTU_SIZE + sizeof(VirtioNetHdr)); |
| 63 | IPL_assert(buf != NULL, "Can not allocate memory for receive buffers"); |
| 64 | vring_send_buf(rxvq, buf, ETH_MTU_SIZE + sizeof(VirtioNetHdr), |
| 65 | VRING_DESC_F_WRITE); |
| 66 | } |
| 67 | vring_notify(rxvq); |
| 68 | |
| 69 | return 0; |
| 70 | } |
| 71 | |
| 72 | int send(int fd, const void *buf, int len, int flags) |
| 73 | { |
| 74 | VirtioNetHdr tx_hdr; |
| 75 | VDev *vdev = virtio_get_device(); |
| 76 | VRing *txvq = &vdev->vrings[VQ_TX]; |
| 77 | |
| 78 | /* Set up header - we do not use anything special, so simply clear it */ |
| 79 | memset(&tx_hdr, 0, sizeof(tx_hdr)); |
| 80 | |
| 81 | vring_send_buf(txvq, &tx_hdr, sizeof(tx_hdr), VRING_DESC_F_NEXT); |
| 82 | vring_send_buf(txvq, (void *)buf, len, VRING_HIDDEN_IS_CHAIN); |
| 83 | while (!vr_poll(txvq)) { |
| 84 | yield(); |
| 85 | } |
| 86 | if (drain_irqs(txvq->schid)) { |
| 87 | puts("send: drain irqs failed"); |
| 88 | return -1; |
| 89 | } |
| 90 | |
| 91 | return len; |
| 92 | } |
| 93 | |
| 94 | int recv(int fd, void *buf, int maxlen, int flags) |
| 95 | { |
| 96 | VDev *vdev = virtio_get_device(); |
| 97 | VRing *rxvq = &vdev->vrings[VQ_RX]; |
| 98 | int len, id; |
| 99 | uint8_t *pkt; |
| 100 | |
| 101 | if (rx_last_idx == rxvq->used->idx) { |
| 102 | return 0; |
| 103 | } |
| 104 | |
| 105 | len = rxvq->used->ring[rx_last_idx % rxvq->num].len - sizeof(VirtioNetHdr); |
| 106 | if (len > maxlen) { |
| 107 | puts("virtio-net: Receive buffer too small"); |
| 108 | len = maxlen; |
| 109 | } |
| 110 | id = rxvq->used->ring[rx_last_idx % rxvq->num].id % rxvq->num; |
| 111 | pkt = (uint8_t *)(rxvq->desc[id].addr + sizeof(VirtioNetHdr)); |
| 112 | |
| 113 | #if DEBUG_VIRTIO_NET /* Dump packet */ |
| 114 | int i; |
| 115 | printf("\nbuf %p: len=%i\n", (void *)rxvq->desc[id].addr, len); |
| 116 | for (i = 0; i < 64; i++) { |
| 117 | printf(" %02x", pkt[i]); |
| 118 | if ((i % 16) == 15) { |
| 119 | printf("\n"); |
| 120 | } |
| 121 | } |
| 122 | printf("\n"); |
| 123 | #endif |
| 124 | |
| 125 | /* Copy data to destination buffer */ |
| 126 | memcpy(buf, pkt, len); |
| 127 | |
| 128 | /* Mark buffer as available to the host again */ |
| 129 | rxvq->avail->ring[rxvq->avail->idx % rxvq->num] = id; |
| 130 | rxvq->avail->idx = rxvq->avail->idx + 1; |
| 131 | vring_notify(rxvq); |
| 132 | |
| 133 | /* Move index to next entry */ |
| 134 | rx_last_idx = rx_last_idx + 1; |
| 135 | |
| 136 | return len; |
| 137 | } |