Differential D26976 Diff 78821 usr.sbin/bhyve/mmio/mmio_virtio_rnd.c

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usr.sbin/bhyve/mmio/mmio_virtio_rnd.c

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				/*-
				* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
				*
				* 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>
				#ifndef WITHOUT_CAPSICUM
				#include <sys/capsicum.h>
				#endif
				#include <sys/linker_set.h>
				#include <sys/uio.h>

				#ifndef WITHOUT_CAPSICUM
				#include <capsicum_helpers.h>
				#endif
				#include <err.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 <dev/pci/pcireg.h>
				#include <sysexits.h>

				#include "bhyverun.h"
				#include "debug.h"

				#include "mmio_emul.h"
				#include "mmio_virtio.h"

				#define VTRND_RINGSZ 64


				static int pci_vtrnd_debug;
				#define DPRINTF(params) if (pci_vtrnd_debug) PRINTLN params
				#define WPRINTF(params) PRINTLN 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 !"));
				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", 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 mmio_devinst pi, char *opts)
				{
				struct pci_vtrnd_softc *sc;
				int fd;
				int len;
				uint8_t v;
				#ifndef WITHOUT_CAPSICUM
				cap_rights_t rights;
				#endif

				/*
				* Should always be able to open /dev/random.
				*/
				fd = open("/dev/random", O_RDONLY \| O_NONBLOCK);

				assert(fd >= 0);

				#ifndef WITHOUT_CAPSICUM
				cap_rights_init(&rights, CAP_READ);
				if (caph_rights_limit(fd, &rights) == -1)
				errx(EX_OSERR, "Unable to apply rights for sandbox");
				#endif

				/*
				* 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));
				close(fd);
				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 */
				vi_devemu_init(pi, VIRTIO_TYPE_ENTROPY);

				if (vi_intr_init(&sc->vrsc_vs, 1, fbsdrun_virtio_msix()))
				return (1);
				vi_set_io_res(&sc->vrsc_vs, 0);

				return (0);
				}


				struct mmio_devemu pci_de_vrnd = {
				.de_emu = "virtio-rnd",
				.de_init = pci_vtrnd_init,
				.de_write = vi_mmio_write,
				.de_read = vi_mmio_read
				};
				MMIO_EMUL_SET(pci_de_vrnd);