2 * Copyright (c) 2014 Nahanni Systems Inc.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 * virtio entropy device emulation.
30 * Randomness is sourced from /dev/random which does not block
31 * once it has been seeded at bootup.
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/param.h>
38 #include <sys/linker_set.h>
54 #define VTRND_RINGSZ 64
57 static int pci_vtrnd_debug;
58 #define DPRINTF(params) if (pci_vtrnd_debug) printf params
59 #define WPRINTF(params) printf params
64 struct pci_vtrnd_softc {
65 struct virtio_softc vrsc_vs;
66 struct vqueue_info vrsc_vq;
67 pthread_mutex_t vrsc_mtx;
72 static void pci_vtrnd_reset(void *);
73 static void pci_vtrnd_notify(void *, struct vqueue_info *);
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 */
89 pci_vtrnd_reset(void *vsc)
91 struct pci_vtrnd_softc *sc;
95 DPRINTF(("vtrnd: device reset requested !\n"));
96 vi_reset_dev(&sc->vrsc_vs);
101 pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
104 struct pci_vtrnd_softc *sc;
110 if (sc->vrsc_fd < 0) {
115 while (vq_has_descs(vq)) {
116 vq_getchain(vq, &idx, &iov, 1, NULL);
118 len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len);
120 DPRINTF(("vtrnd: vtrnd_notify(): %d\r\n", len));
122 /* Catastrophe if unable to read from /dev/random */
126 * Release this chain and handle more
128 vq_relchain(vq, idx, len);
130 vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
135 pci_vtrnd_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
137 struct pci_vtrnd_softc *sc;
143 * Should always be able to open /dev/random.
145 fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
150 * Check that device is seeded and non-blocking.
152 len = read(fd, &v, sizeof(v));
154 WPRINTF(("vtrnd: /dev/random not ready, read(): %d", len));
158 sc = calloc(1, sizeof(struct pci_vtrnd_softc));
160 vi_softc_linkup(&sc->vrsc_vs, &vtrnd_vi_consts, sc, pi, &sc->vrsc_vq);
161 sc->vrsc_vs.vs_mtx = &sc->vrsc_mtx;
163 sc->vrsc_vq.vq_qsize = VTRND_RINGSZ;
165 /* keep /dev/random opened while emulating */
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 pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
175 if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix()))
177 vi_set_io_bar(&sc->vrsc_vs, 0);
183 struct pci_devemu pci_de_vrnd = {
184 .pe_emu = "virtio-rnd",
185 .pe_init = pci_vtrnd_init,
186 .pe_barwrite = vi_pci_write,
187 .pe_barread = vi_pci_read
189 PCI_EMUL_SET(pci_de_vrnd);