2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2014 Nahanni Systems Inc.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer
12 * in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * virtio entropy device emulation.
32 * Randomness is sourced from /dev/random which does not block
33 * once it has been seeded at bootup.
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
39 #include <sys/param.h>
40 #ifndef WITHOUT_CAPSICUM
41 #include <sys/capsicum.h>
43 #include <sys/linker_set.h>
46 #ifndef WITHOUT_CAPSICUM
47 #include <capsicum_helpers.h>
65 #define VTRND_RINGSZ 64
68 static int pci_vtrnd_debug;
69 #define DPRINTF(params) if (pci_vtrnd_debug) PRINTLN params
70 #define WPRINTF(params) PRINTLN params
75 struct pci_vtrnd_softc {
76 struct virtio_softc vrsc_vs;
77 struct vqueue_info vrsc_vq;
78 pthread_mutex_t vrsc_mtx;
83 static void pci_vtrnd_reset(void *);
84 static void pci_vtrnd_notify(void *, struct vqueue_info *);
86 static struct virtio_consts vtrnd_vi_consts = {
87 "vtrnd", /* our name */
88 1, /* we support 1 virtqueue */
89 0, /* config reg size */
90 pci_vtrnd_reset, /* reset */
91 pci_vtrnd_notify, /* device-wide qnotify */
92 NULL, /* read virtio config */
93 NULL, /* write virtio config */
94 NULL, /* apply negotiated features */
95 0, /* our capabilities */
100 pci_vtrnd_reset(void *vsc)
102 struct pci_vtrnd_softc *sc;
106 DPRINTF(("vtrnd: device reset requested !"));
107 vi_reset_dev(&sc->vrsc_vs);
112 pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
115 struct pci_vtrnd_softc *sc;
121 if (sc->vrsc_fd < 0) {
126 while (vq_has_descs(vq)) {
127 vq_getchain(vq, &idx, &iov, 1, NULL);
129 len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len);
131 DPRINTF(("vtrnd: vtrnd_notify(): %d", len));
133 /* Catastrophe if unable to read from /dev/random */
137 * Release this chain and handle more
139 vq_relchain(vq, idx, len);
141 vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
146 pci_vtrnd_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
148 struct pci_vtrnd_softc *sc;
152 #ifndef WITHOUT_CAPSICUM
157 * Should always be able to open /dev/random.
159 fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
163 #ifndef WITHOUT_CAPSICUM
164 cap_rights_init(&rights, CAP_READ);
165 if (caph_rights_limit(fd, &rights) == -1)
166 errx(EX_OSERR, "Unable to apply rights for sandbox");
170 * Check that device is seeded and non-blocking.
172 len = read(fd, &v, sizeof(v));
174 WPRINTF(("vtrnd: /dev/random not ready, read(): %d", len));
179 sc = calloc(1, sizeof(struct pci_vtrnd_softc));
181 vi_softc_linkup(&sc->vrsc_vs, &vtrnd_vi_consts, sc, pi, &sc->vrsc_vq);
182 sc->vrsc_vs.vs_mtx = &sc->vrsc_mtx;
184 sc->vrsc_vq.vq_qsize = VTRND_RINGSZ;
186 /* keep /dev/random opened while emulating */
189 /* initialize config space */
190 pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_RANDOM);
191 pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
192 pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_CRYPTO);
193 pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_ENTROPY);
194 pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
196 if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix()))
198 vi_set_io_bar(&sc->vrsc_vs, 0);
204 struct pci_devemu pci_de_vrnd = {
205 .pe_emu = "virtio-rnd",
206 .pe_init = pci_vtrnd_init,
207 .pe_barwrite = vi_pci_write,
208 .pe_barread = vi_pci_read,
209 #ifdef BHYVE_SNAPSHOT
210 .pe_snapshot = vi_pci_snapshot,
213 PCI_EMUL_SET(pci_de_vrnd);