diff options
author | jhb <jhb@FreeBSD.org> | 2014-07-21 00:21:56 +0000 |
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committer | jhb <jhb@FreeBSD.org> | 2014-07-21 00:21:56 +0000 |
commit | cf1a2223269e3a031a511b90ce2035ffdf9f7420 (patch) | |
tree | 47f56b4d318aeb5e1020c53d57cb9963e35eeb27 /usr.sbin/bhyve/pci_virtio_rnd.c | |
parent | 25b41d088263e9d1574521319b2e37df9842fd2f (diff) | |
download | FreeBSD-src-cf1a2223269e3a031a511b90ce2035ffdf9f7420.zip FreeBSD-src-cf1a2223269e3a031a511b90ce2035ffdf9f7420.tar.gz |
MFC 260847,264055,264867:
- Add a very simple virtio_random(4) driver for FreeBSD guests to harvest
entropy from hypervisors.
- Add support to bhyve for the virtio RNG entropy-source device to provide
entry to bhyve guests.
Diffstat (limited to 'usr.sbin/bhyve/pci_virtio_rnd.c')
-rw-r--r-- | usr.sbin/bhyve/pci_virtio_rnd.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/usr.sbin/bhyve/pci_virtio_rnd.c b/usr.sbin/bhyve/pci_virtio_rnd.c new file mode 100644 index 0000000..38459d2 --- /dev/null +++ b/usr.sbin/bhyve/pci_virtio_rnd.c @@ -0,0 +1,189 @@ +/*- + * 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 */ + 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; + + sc = vsc; + + vq_startchains(vq); + + if (sc->vrsc_fd < 0) { + vq_endchains(vq, 0); + return; + } + + while (vq_has_descs(vq)) { + vq_getchain(vq, &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, 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 = malloc(sizeof(struct pci_vtrnd_softc)); + memset(sc, 0, 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); + + 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); |