1 /*- 2 * Copyright (c) 2014 Nahanni Systems Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * virtio entropy device emulation. 30 * Randomness is sourced from /dev/random which does not block 31 * once it has been seeded at bootup. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include <sys/param.h> 38 #include <sys/linker_set.h> 39 #include <sys/uio.h> 40 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 #include <assert.h> 48 #include <pthread.h> 49 50 #include "bhyverun.h" 51 #include "pci_emul.h" 52 #include "virtio.h" 53 54 #define VTRND_RINGSZ 64 55 56 57 static int pci_vtrnd_debug; 58 #define DPRINTF(params) if (pci_vtrnd_debug) printf params 59 #define WPRINTF(params) printf params 60 61 /* 62 * Per-device softc 63 */ 64 struct pci_vtrnd_softc { 65 struct virtio_softc vrsc_vs; 66 struct vqueue_info vrsc_vq; 67 pthread_mutex_t vrsc_mtx; 68 uint64_t vrsc_cfg; 69 int vrsc_fd; 70 }; 71 72 static void pci_vtrnd_reset(void *); 73 static void pci_vtrnd_notify(void *, struct vqueue_info *); 74 75 static struct virtio_consts vtrnd_vi_consts = { 76 "vtrnd", /* our name */ 77 1, /* we support 1 virtqueue */ 78 0, /* config reg size */ 79 pci_vtrnd_reset, /* reset */ 80 pci_vtrnd_notify, /* device-wide qnotify */ 81 NULL, /* read virtio config */ 82 NULL, /* write virtio config */ 83 NULL, /* apply negotiated features */ 84 0, /* our capabilities */ 85 }; 86 87 88 static void 89 pci_vtrnd_reset(void *vsc) 90 { 91 struct pci_vtrnd_softc *sc; 92 93 sc = vsc; 94 95 DPRINTF(("vtrnd: device reset requested !\n")); 96 vi_reset_dev(&sc->vrsc_vs); 97 } 98 99 100 static void 101 pci_vtrnd_notify(void *vsc, struct vqueue_info *vq) 102 { 103 struct iovec iov; 104 struct pci_vtrnd_softc *sc; 105 int len; 106 uint16_t idx; 107 108 sc = vsc; 109 110 if (sc->vrsc_fd < 0) { 111 vq_endchains(vq, 0); 112 return; 113 } 114 115 while (vq_has_descs(vq)) { 116 vq_getchain(vq, &idx, &iov, 1, NULL); 117 118 len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len); 119 120 DPRINTF(("vtrnd: vtrnd_notify(): %d\r\n", len)); 121 122 /* Catastrophe if unable to read from /dev/random */ 123 assert(len > 0); 124 125 /* 126 * Release this chain and handle more 127 */ 128 vq_relchain(vq, idx, len); 129 } 130 vq_endchains(vq, 1); /* Generate interrupt if appropriate. */ 131 } 132 133 134 static int 135 pci_vtrnd_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts) 136 { 137 struct pci_vtrnd_softc *sc; 138 int fd; 139 int len; 140 uint8_t v; 141 142 /* 143 * Should always be able to open /dev/random. 144 */ 145 fd = open("/dev/random", O_RDONLY | O_NONBLOCK); 146 147 assert(fd >= 0); 148 149 /* 150 * Check that device is seeded and non-blocking. 151 */ 152 len = read(fd, &v, sizeof(v)); 153 if (len <= 0) { 154 WPRINTF(("vtrnd: /dev/random not ready, read(): %d", len)); 155 return (1); 156 } 157 158 sc = calloc(1, sizeof(struct pci_vtrnd_softc)); 159 160 vi_softc_linkup(&sc->vrsc_vs, &vtrnd_vi_consts, sc, pi, &sc->vrsc_vq); 161 sc->vrsc_vs.vs_mtx = &sc->vrsc_mtx; 162 163 sc->vrsc_vq.vq_qsize = VTRND_RINGSZ; 164 165 /* keep /dev/random opened while emulating */ 166 sc->vrsc_fd = fd; 167 168 /* initialize config space */ 169 pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_RANDOM); 170 pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR); 171 pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_CRYPTO); 172 pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_ENTROPY); 173 174 if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix())) 175 return (1); 176 vi_set_io_bar(&sc->vrsc_vs, 0); 177 178 return (0); 179 } 180 181 182 struct pci_devemu pci_de_vrnd = { 183 .pe_emu = "virtio-rnd", 184 .pe_init = pci_vtrnd_init, 185 .pe_barwrite = vi_pci_write, 186 .pe_barread = vi_pci_read 187 }; 188 PCI_EMUL_SET(pci_de_vrnd); 189