/*-
* Copyright (c) 2014 Nahanni Systems Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* virtio entropy device emulation.
* Randomness is sourced from /dev/random which does not block
* once it has been seeded at bootup.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/linker_set.h>
#include <sys/uio.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <pthread.h>
#include "bhyverun.h"
#include "pci_emul.h"
#include "virtio.h"
#define VTRND_RINGSZ 64
static int pci_vtrnd_debug;
#define DPRINTF(params) if (pci_vtrnd_debug) printf params
#define WPRINTF(params) printf params
/*
* Per-device softc
*/
struct pci_vtrnd_softc {
struct virtio_softc vrsc_vs;
struct vqueue_info vrsc_vq;
pthread_mutex_t vrsc_mtx;
uint64_t vrsc_cfg;
int vrsc_fd;
};
static void pci_vtrnd_reset(void *);
static void pci_vtrnd_notify(void *, struct vqueue_info *);
static struct virtio_consts vtrnd_vi_consts = {
"vtrnd", /* our name */
1, /* we support 1 virtqueue */
0, /* config reg size */
pci_vtrnd_reset, /* reset */
pci_vtrnd_notify, /* device-wide qnotify */
NULL, /* read virtio config */
NULL, /* write virtio config */
NULL, /* apply negotiated features */
0, /* our capabilities */
};
static void
pci_vtrnd_reset(void *vsc)
{
struct pci_vtrnd_softc *sc;
sc = vsc;
DPRINTF(("vtrnd: device reset requested !\n"));
vi_reset_dev(&sc->vrsc_vs);
}
static void
pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
{
struct iovec iov;
struct pci_vtrnd_softc *sc;
int len;
uint16_t idx;
sc = vsc;
if (sc->vrsc_fd < 0) {
vq_endchains(vq, 0);
return;
}
while (vq_has_descs(vq)) {
vq_getchain(vq, &idx, &iov, 1, NULL);
len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len);
DPRINTF(("vtrnd: vtrnd_notify(): %d\r\n", len));
/* Catastrophe if unable to read from /dev/random */
assert(len > 0);
/*
* Release this chain and handle more
*/
vq_relchain(vq, idx, len);
}
vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
}
static int
pci_vtrnd_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
{
struct pci_vtrnd_softc *sc;
int fd;
int len;
uint8_t v;
/*
* Should always be able to open /dev/random.
*/
fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
assert(fd >= 0);
/*
* Check that device is seeded and non-blocking.
*/
len = read(fd, &v, sizeof(v));
if (len <= 0) {
WPRINTF(("vtrnd: /dev/random not ready, read(): %d", len));
return (1);
}
sc = calloc(1, sizeof(struct pci_vtrnd_softc));
vi_softc_linkup(&sc->vrsc_vs, &vtrnd_vi_consts, sc, pi, &sc->vrsc_vq);
sc->vrsc_vs.vs_mtx = &sc->vrsc_mtx;
sc->vrsc_vq.vq_qsize = VTRND_RINGSZ;
/* keep /dev/random opened while emulating */
sc->vrsc_fd = fd;
/* initialize config space */
pci_set_cfgdata16(pi, PCIR_DEVICE, VIRTIO_DEV_RANDOM);
pci_set_cfgdata16(pi, PCIR_VENDOR, VIRTIO_VENDOR);
pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_CRYPTO);
pci_set_cfgdata16(pi, PCIR_SUBDEV_0, VIRTIO_TYPE_ENTROPY);
pci_set_cfgdata16(pi, PCIR_SUBVEND_0, VIRTIO_VENDOR);
if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix()))
return (1);
vi_set_io_bar(&sc->vrsc_vs, 0);
return (0);
}
struct pci_devemu pci_de_vrnd = {
.pe_emu = "virtio-rnd",
.pe_init = pci_vtrnd_init,
.pe_barwrite = vi_pci_write,
.pe_barread = vi_pci_read
};
PCI_EMUL_SET(pci_de_vrnd);
