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Add very simple virtio_random(4) driver to harvest entropy from host

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Reviewed by:	markm (random bits only)
This commit is contained in:
Bryan Venteicher 2014-01-18 06:14:38 +00:00
parent 5ed2724da0
commit 10c4018057
10 changed files with 336 additions and 1 deletions
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2
share/man/man4/Makefile
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@ -543,6 +543,7 @@ MAN= aac.4 \
${_virtio.4} \
${_virtio_balloon.4} \
${_virtio_blk.4} \
${_virtio_random.4} \
${_virtio_scsi.4} \
vkbd.4 \
vlan.4 \
@ -787,6 +788,7 @@ _nxge.4= nxge.4
_virtio.4= virtio.4
_virtio_balloon.4=virtio_balloon.4
_virtio_blk.4= virtio_blk.4
_virtio_random.4= virtio_random.4
_virtio_scsi.4= virtio_scsi.4
_vmx.4= vmx.4
_vtnet.4= vtnet.4

61
share/man/man4/virtio_random.4 Normal file
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@ -0,0 +1,61 @@
.\" Copyright (c) 2013 Bryan Venteicher
.\" 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.
.\" 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.
.\"
.\" $FreeBSD$
.\"
.Dd December 28, 2013
.Dt VIRTIO_RANDOM 4
.Os
.Sh NAME
.Nm virtio_random
.Nd VirtIO Entropy driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device virtio_random"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
virtio_random_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
device driver provides support for VirtIO entropy devices.
.Pp
The entropy device supplies high-quality randomness from the
hypervisor to the guest.
.Sh SEE ALSO
.Xr random 4
.Xr virtio 4
.Sh HISTORY
The
.Nm
driver was written by
.An Bryan Venteicher Aq bryanv@FreeBSD.org .

1
sys/amd64/conf/NOTES
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@ -472,6 +472,7 @@ device vtnet # VirtIO Ethernet device
device virtio_blk # VirtIO Block device
device virtio_scsi # VirtIO SCSI device
device virtio_balloon # VirtIO Memory Balloon device
device virtio_random # VirtIO Entropy device
device hyperv # HyperV drivers

1
sys/conf/files.amd64
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@ -448,6 +448,7 @@ dev/virtio/network/if_vtnet.c optional vtnet
dev/virtio/block/virtio_blk.c optional virtio_blk
dev/virtio/balloon/virtio_balloon.c optional virtio_balloon
dev/virtio/scsi/virtio_scsi.c optional virtio_scsi
dev/virtio/random/virtio_random.c optional virtio_random
isa/syscons_isa.c optional sc
isa/vga_isa.c optional vga
kern/kern_clocksource.c standard

1
sys/conf/files.i386
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@ -414,6 +414,7 @@ dev/virtio/network/if_vtnet.c optional vtnet
dev/virtio/block/virtio_blk.c optional virtio_blk
dev/virtio/balloon/virtio_balloon.c optional virtio_balloon
dev/virtio/scsi/virtio_scsi.c optional virtio_scsi
dev/virtio/random/virtio_random.c optional virtio_random
i386/acpica/acpi_machdep.c optional acpi
acpi_wakecode.o optional acpi \
dependency "$S/i386/acpica/acpi_wakecode.S assym.s" \

231
sys/dev/virtio/random/virtio_random.c Normal file
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@ -0,0 +1,231 @@
/*-
* Copyright (c) 2013, Bryan Venteicher <bryanv@FreeBSD.org>
* 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 unmodified, this list of conditions, and the following
* disclaimer.
* 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 ``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 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.
*/
/* Driver for VirtIO entropy device. */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sglist.h>
#include <sys/callout.h>
#include <sys/random.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <dev/virtio/virtio.h>
#include <dev/virtio/virtqueue.h>
struct vtrnd_softc {
device_t vtrnd_dev;
uint64_t vtrnd_features;
struct callout vtrnd_callout;
struct virtqueue *vtrnd_vq;
};
static int vtrnd_modevent(module_t, int, void *);
static int vtrnd_probe(device_t);
static int vtrnd_attach(device_t);
static int vtrnd_detach(device_t);
static void vtrnd_negotiate_features(struct vtrnd_softc *);
static int vtrnd_alloc_virtqueue(struct vtrnd_softc *);
static void vtrnd_harvest(struct vtrnd_softc *);
static void vtrnd_timer(void *);
#define VTRND_FEATURES 0
static struct virtio_feature_desc vtrnd_feature_desc[] = {
{ 0, NULL }
};
static device_method_t vtrnd_methods[] = {
/* Device methods. */
DEVMETHOD(device_probe, vtrnd_probe),
DEVMETHOD(device_attach, vtrnd_attach),
DEVMETHOD(device_detach, vtrnd_detach),
DEVMETHOD_END
};
static driver_t vtrnd_driver = {
"vtrnd",
vtrnd_methods,
sizeof(struct vtrnd_softc)
};
static devclass_t vtrnd_devclass;
DRIVER_MODULE(virtio_random, virtio_pci, vtrnd_driver, vtrnd_devclass,
vtrnd_modevent, 0);
MODULE_VERSION(virtio_random, 1);
MODULE_DEPEND(virtio_random, virtio, 1, 1, 1);
static int
vtrnd_modevent(module_t mod, int type, void *unused)
{
int error;
switch (type) {
case MOD_LOAD:
case MOD_QUIESCE:
case MOD_UNLOAD:
case MOD_SHUTDOWN:
error = 0;
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
vtrnd_probe(device_t dev)
{
if (virtio_get_device_type(dev) != VIRTIO_ID_ENTROPY)
return (ENXIO);
device_set_desc(dev, "VirtIO Entropy Adapter");
return (BUS_PROBE_DEFAULT);
}
static int
vtrnd_attach(device_t dev)
{
struct vtrnd_softc *sc;
int error;
sc = device_get_softc(dev);
sc->vtrnd_dev = dev;
callout_init(&sc->vtrnd_callout, CALLOUT_MPSAFE);
virtio_set_feature_desc(dev, vtrnd_feature_desc);
vtrnd_negotiate_features(sc);
error = vtrnd_alloc_virtqueue(sc);
if (error) {
device_printf(dev, "cannot allocate virtqueue\n");
goto fail;
}
callout_reset(&sc->vtrnd_callout, 5 * hz, vtrnd_timer, sc);
fail:
if (error)
vtrnd_detach(dev);
return (error);
}
static int
vtrnd_detach(device_t dev)
{
struct vtrnd_softc *sc;
sc = device_get_softc(dev);
callout_stop(&sc->vtrnd_callout);
return (0);
}
static void
vtrnd_negotiate_features(struct vtrnd_softc *sc)
{
device_t dev;
uint64_t features;
dev = sc->vtrnd_dev;
features = VTRND_FEATURES;
sc->vtrnd_features = virtio_negotiate_features(dev, features);
}
static int
vtrnd_alloc_virtqueue(struct vtrnd_softc *sc)
{
device_t dev;
struct vq_alloc_info vq_info;
dev = sc->vtrnd_dev;
VQ_ALLOC_INFO_INIT(&vq_info, 0, NULL, sc, &sc->vtrnd_vq,
"%s request", device_get_nameunit(dev));
return (virtio_alloc_virtqueues(dev, 0, 1, &vq_info));
}
static void
vtrnd_harvest(struct vtrnd_softc *sc)
{
struct sglist_seg segs[1];
struct sglist sg;
struct virtqueue *vq;
uint32_t value;
int error;
vq = sc->vtrnd_vq;
sglist_init(&sg, 1, segs);
error = sglist_append(&sg, &value, sizeof(value));
KASSERT(error == 0 && sg.sg_nseg == 1,
("%s: error %d adding buffer to sglist", __func__, error));
if (!virtqueue_empty(vq))
return;
if (virtqueue_enqueue(vq, &value, &sg, 0, 1) != 0)
return;
/*
* Poll for the response, but the command is likely already
* done when we return from the notify.
*/
virtqueue_notify(vq);
virtqueue_poll(vq, NULL);
random_harvest(&value, sizeof(value), sizeof(value) * NBBY / 2,
RANDOM_PURE_VIRTIO);
}
static void
vtrnd_timer(void *xsc)
{
struct vtrnd_softc *sc;
sc = xsc;
vtrnd_harvest(sc);
callout_schedule(&sc->vtrnd_callout, 5 * hz);
}

1
sys/i386/conf/NOTES
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@ -800,6 +800,7 @@ device vtnet # VirtIO Ethernet device
device virtio_blk # VirtIO Block device
device virtio_scsi # VirtIO SCSI device
device virtio_balloon # VirtIO Memory Balloon device
device virtio_random # VirtIO Entropy device
device hyperv # HyperV drivers

2
sys/modules/virtio/Makefile
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@ -23,6 +23,6 @@
# SUCH DAMAGE.
#
SUBDIR= virtio pci network block balloon scsi
SUBDIR= virtio pci network block balloon scsi random
.include <bsd.subdir.mk>

36
sys/modules/virtio/random/Makefile Normal file
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@ -0,0 +1,36 @@
#
# $FreeBSD$
#
# 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.
# 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.
#
.PATH: ${.CURDIR}/../../../dev/virtio/random
KMOD= virtio_random
SRCS= virtio_random.c
SRCS+= virtio_bus_if.h virtio_if.h
SRCS+= bus_if.h device_if.h
MFILES= kern/bus_if.m kern/device_if.m \
dev/virtio/virtio_bus_if.m dev/virtio/virtio_if.m
.include <bsd.kmod.mk>

1
sys/sys/random.h
View File

@ -56,6 +56,7 @@ enum esource {
RANDOM_PURE_RDRAND,
RANDOM_PURE_NEHEMIAH,
RANDOM_PURE_RNDTEST,
RANDOM_PURE_VIRTIO,
ENTROPYSOURCE
};
void random_harvest(const void *, u_int, u_int, enum esource);