Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
* Stefan Hajnoczi (stefa...@redhat.com) wrote:
> On Wed, Aug 21, 2019 at 08:11:18PM +0100, Dr. David Alan Gilbert wrote:
> > * Michael S. Tsirkin (m...@redhat.com) wrote:
> > > On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git)
> > > wrote:
> > > > +static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> > > > +{
> > > > +/* Do nothing */
> > >
> > > Why is this safe? Is this because this never triggers? assert(0) then?
> > > If it triggers then backend won't be notified, which might
> > > cause it to get stuck.
> >
> > We never process these queues in qemu - always in the guest; so am I
> > correct in thinking those shouldn't be used?
>
> s/guest/vhost-user backend process/
>
> vuf_handle_output() should never be called.
It turns out it does get called in one case during cleanup, in the case
where the daemon died before qemu, virtio_bus_cleanup_host_notifier goes
around the notifiers and calls all the ones where there's anything left
in the eventfd.
Dave
> > > > +}
> > > > +
> > > > +static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx,
> > > > +bool mask)
> > > > +{
> > > > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > > > +
> > > > +vhost_virtqueue_mask(>vhost_dev, vdev, idx, mask);
> > > > +}
> > > > +
> > > > +static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx)
> > > > +{
> > > > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > > > +
> > > > +return vhost_virtqueue_pending(>vhost_dev, idx);
> > > > +}
> > > > +
> > > > +static void vuf_device_realize(DeviceState *dev, Error **errp)
> > > > +{
> > > > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > > > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > > > +unsigned int i;
> > > > +size_t len;
> > > > +int ret;
> > > > +
> > > > +if (!fs->conf.chardev.chr) {
> > > > +error_setg(errp, "missing chardev");
> > > > +return;
> > > > +}
> > > > +
> > > > +if (!fs->conf.tag) {
> > > > +error_setg(errp, "missing tag property");
> > > > +return;
> > > > +}
> > > > +len = strlen(fs->conf.tag);
> > > > +if (len == 0) {
> > > > +error_setg(errp, "tag property cannot be empty");
> > > > +return;
> > > > +}
> > > > +if (len > sizeof_field(struct virtio_fs_config, tag)) {
> > > > +error_setg(errp, "tag property must be %zu bytes or less",
> > > > + sizeof_field(struct virtio_fs_config, tag));
> > > > +return;
> > > > +}
> > > > +
> > > > +if (fs->conf.num_queues == 0) {
> > > > +error_setg(errp, "num-queues property must be larger than 0");
> > > > +return;
> > > > +}
> > >
> > > The strange thing is that actual # of queues is this number + 2.
> > > And this affects an optimal number of vectors (see patch 2).
> > > Not sure what a good solution is - include the
> > > mandatory queues in the number?
> > > Needs to be documented in some way.
> >
> > Should we be doing nvectors the same way virtio-scsi-pci does it;
> > with a magic 'unspecified' default where it sets the nvectors based on
> > the number of queues?
> >
> > I think my preference is not to show the users the mandatory queues.
>
> I agree. Users want to control multiqueue, not on the absolute number
> of virtqueues including mandatory queues.
>
> > > > +
> > > > +if (!is_power_of_2(fs->conf.queue_size)) {
> > > > +error_setg(errp, "queue-size property must be a power of 2");
> > > > +return;
> > > > +}
> > >
> > > Hmm packed ring allows non power of 2 ...
> > > We need to look into a generic helper to support VQ
> > > size checks.
> >
> > Which would also have to include the negotiation of where it's doing
> > packaged ring?
>
> It's impossible to perform this check at .realize() time since the
> packed virtqueue layout is negotiated via a VIRTIO feature bit. This
> puts us in the awkward position of either failing when the guest has
> already booted or rounding up the queue size for split ring layouts
> (with a warning message?).
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
On Thu, Aug 22, 2019 at 11:19:16AM +0200, Cornelia Huck wrote:
> On Thu, 22 Aug 2019 09:52:37 +0100
> Stefan Hajnoczi wrote:
>
> > On Wed, Aug 21, 2019 at 08:11:18PM +0100, Dr. David Alan Gilbert wrote:
> > > * Michael S. Tsirkin (m...@redhat.com) wrote:
> > > > On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git)
> > > > wrote:
>
> > > > > +static void vuf_device_realize(DeviceState *dev, Error **errp)
> > > > > +{
> > > > > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > > > > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > > > > +unsigned int i;
> > > > > +size_t len;
> > > > > +int ret;
> > > > > +
> > > > > +if (!fs->conf.chardev.chr) {
> > > > > +error_setg(errp, "missing chardev");
> > > > > +return;
> > > > > +}
> > > > > +
> > > > > +if (!fs->conf.tag) {
> > > > > +error_setg(errp, "missing tag property");
> > > > > +return;
> > > > > +}
> > > > > +len = strlen(fs->conf.tag);
> > > > > +if (len == 0) {
> > > > > +error_setg(errp, "tag property cannot be empty");
> > > > > +return;
> > > > > +}
> > > > > +if (len > sizeof_field(struct virtio_fs_config, tag)) {
> > > > > +error_setg(errp, "tag property must be %zu bytes or less",
> > > > > + sizeof_field(struct virtio_fs_config, tag));
> > > > > +return;
> > > > > +}
> > > > > +
> > > > > +if (fs->conf.num_queues == 0) {
> > > > > +error_setg(errp, "num-queues property must be larger than
> > > > > 0");
> > > > > +return;
> > > > > +}
> > > >
> > > > The strange thing is that actual # of queues is this number + 2.
> > > > And this affects an optimal number of vectors (see patch 2).
> > > > Not sure what a good solution is - include the
> > > > mandatory queues in the number?
> > > > Needs to be documented in some way.
> > >
> > > Should we be doing nvectors the same way virtio-scsi-pci does it;
> > > with a magic 'unspecified' default where it sets the nvectors based on
> > > the number of queues?
> > >
> > > I think my preference is not to show the users the mandatory queues.
> >
> > I agree. Users want to control multiqueue, not on the absolute number
> > of virtqueues including mandatory queues.
>
> I agree as well, but let me advocate again for renaming this to
> 'num_request_queues' or similar to make it more obvious what this number
> actually means.
Good idea.
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Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
On Thu, 22 Aug 2019 09:52:37 +0100
Stefan Hajnoczi wrote:
> On Wed, Aug 21, 2019 at 08:11:18PM +0100, Dr. David Alan Gilbert wrote:
> > * Michael S. Tsirkin (m...@redhat.com) wrote:
> > > On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git)
> > > wrote:
> > > > +static void vuf_device_realize(DeviceState *dev, Error **errp)
> > > > +{
> > > > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > > > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > > > +unsigned int i;
> > > > +size_t len;
> > > > +int ret;
> > > > +
> > > > +if (!fs->conf.chardev.chr) {
> > > > +error_setg(errp, "missing chardev");
> > > > +return;
> > > > +}
> > > > +
> > > > +if (!fs->conf.tag) {
> > > > +error_setg(errp, "missing tag property");
> > > > +return;
> > > > +}
> > > > +len = strlen(fs->conf.tag);
> > > > +if (len == 0) {
> > > > +error_setg(errp, "tag property cannot be empty");
> > > > +return;
> > > > +}
> > > > +if (len > sizeof_field(struct virtio_fs_config, tag)) {
> > > > +error_setg(errp, "tag property must be %zu bytes or less",
> > > > + sizeof_field(struct virtio_fs_config, tag));
> > > > +return;
> > > > +}
> > > > +
> > > > +if (fs->conf.num_queues == 0) {
> > > > +error_setg(errp, "num-queues property must be larger than 0");
> > > > +return;
> > > > +}
> > >
> > > The strange thing is that actual # of queues is this number + 2.
> > > And this affects an optimal number of vectors (see patch 2).
> > > Not sure what a good solution is - include the
> > > mandatory queues in the number?
> > > Needs to be documented in some way.
> >
> > Should we be doing nvectors the same way virtio-scsi-pci does it;
> > with a magic 'unspecified' default where it sets the nvectors based on
> > the number of queues?
> >
> > I think my preference is not to show the users the mandatory queues.
>
> I agree. Users want to control multiqueue, not on the absolute number
> of virtqueues including mandatory queues.
I agree as well, but let me advocate again for renaming this to
'num_request_queues' or similar to make it more obvious what this number
actually means.
>
> > > > +
> > > > +if (!is_power_of_2(fs->conf.queue_size)) {
> > > > +error_setg(errp, "queue-size property must be a power of 2");
> > > > +return;
> > > > +}
> > >
> > > Hmm packed ring allows non power of 2 ...
> > > We need to look into a generic helper to support VQ
> > > size checks.
> >
> > Which would also have to include the negotiation of where it's doing
> > packaged ring?
>
> It's impossible to perform this check at .realize() time since the
> packed virtqueue layout is negotiated via a VIRTIO feature bit. This
> puts us in the awkward position of either failing when the guest has
> already booted or rounding up the queue size for split ring layouts
> (with a warning message?).
I fear that is always going to be awkward if you allow to specify the
queue size via a property. Basically, you can do two things: fail to
accept FEATURES_OK if the queue size is not a power of 2 and the guest
did not negotiate packed ring, or disallow to set a non power of 2
value here, which is what the other devices with such a property
currently do (see also my other mail.) Would probably be good if all
devices used the same approach (when we introduced packed ring support.)
Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
On Wed, Aug 21, 2019 at 08:11:18PM +0100, Dr. David Alan Gilbert wrote:
> * Michael S. Tsirkin (m...@redhat.com) wrote:
> > On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git)
> > wrote:
> > > +static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq)
> > > +{
> > > +/* Do nothing */
> >
> > Why is this safe? Is this because this never triggers? assert(0) then?
> > If it triggers then backend won't be notified, which might
> > cause it to get stuck.
>
> We never process these queues in qemu - always in the guest; so am I
> correct in thinking those shouldn't be used?
s/guest/vhost-user backend process/
vuf_handle_output() should never be called.
> > > +}
> > > +
> > > +static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx,
> > > +bool mask)
> > > +{
> > > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > > +
> > > +vhost_virtqueue_mask(>vhost_dev, vdev, idx, mask);
> > > +}
> > > +
> > > +static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx)
> > > +{
> > > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > > +
> > > +return vhost_virtqueue_pending(>vhost_dev, idx);
> > > +}
> > > +
> > > +static void vuf_device_realize(DeviceState *dev, Error **errp)
> > > +{
> > > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > > +unsigned int i;
> > > +size_t len;
> > > +int ret;
> > > +
> > > +if (!fs->conf.chardev.chr) {
> > > +error_setg(errp, "missing chardev");
> > > +return;
> > > +}
> > > +
> > > +if (!fs->conf.tag) {
> > > +error_setg(errp, "missing tag property");
> > > +return;
> > > +}
> > > +len = strlen(fs->conf.tag);
> > > +if (len == 0) {
> > > +error_setg(errp, "tag property cannot be empty");
> > > +return;
> > > +}
> > > +if (len > sizeof_field(struct virtio_fs_config, tag)) {
> > > +error_setg(errp, "tag property must be %zu bytes or less",
> > > + sizeof_field(struct virtio_fs_config, tag));
> > > +return;
> > > +}
> > > +
> > > +if (fs->conf.num_queues == 0) {
> > > +error_setg(errp, "num-queues property must be larger than 0");
> > > +return;
> > > +}
> >
> > The strange thing is that actual # of queues is this number + 2.
> > And this affects an optimal number of vectors (see patch 2).
> > Not sure what a good solution is - include the
> > mandatory queues in the number?
> > Needs to be documented in some way.
>
> Should we be doing nvectors the same way virtio-scsi-pci does it;
> with a magic 'unspecified' default where it sets the nvectors based on
> the number of queues?
>
> I think my preference is not to show the users the mandatory queues.
I agree. Users want to control multiqueue, not on the absolute number
of virtqueues including mandatory queues.
> > > +
> > > +if (!is_power_of_2(fs->conf.queue_size)) {
> > > +error_setg(errp, "queue-size property must be a power of 2");
> > > +return;
> > > +}
> >
> > Hmm packed ring allows non power of 2 ...
> > We need to look into a generic helper to support VQ
> > size checks.
>
> Which would also have to include the negotiation of where it's doing
> packaged ring?
It's impossible to perform this check at .realize() time since the
packed virtqueue layout is negotiated via a VIRTIO feature bit. This
puts us in the awkward position of either failing when the guest has
already booted or rounding up the queue size for split ring layouts
(with a warning message?).
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Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
* Michael S. Tsirkin (m...@redhat.com) wrote:
> On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert"
> >
> > The virtio-fs virtio device provides shared file system access using
> > the FUSE protocol carried ovew virtio.
> > The actual file server is implemented in an external vhost-user-fs device
> > backend process.
> >
> > Signed-off-by: Stefan Hajnoczi
> > Signed-off-by: Sebastien Boeuf
> > Signed-off-by: Dr. David Alan Gilbert
> > ---
> > configure | 13 +
> > hw/virtio/Makefile.objs | 1 +
> > hw/virtio/vhost-user-fs.c | 297
> > include/hw/virtio/vhost-user-fs.h | 45 +++
> > include/standard-headers/linux/virtio_fs.h | 41 +++
> > include/standard-headers/linux/virtio_ids.h | 1 +
> > 6 files changed, 398 insertions(+)
> > create mode 100644 hw/virtio/vhost-user-fs.c
> > create mode 100644 include/hw/virtio/vhost-user-fs.h
> > create mode 100644 include/standard-headers/linux/virtio_fs.h
> >
> > diff --git a/configure b/configure
> > index 714e7fb6a1..e7e33ee783 100755
> > --- a/configure
> > +++ b/configure
> > @@ -382,6 +382,7 @@ vhost_crypto=""
> > vhost_scsi=""
> > vhost_vsock=""
> > vhost_user=""
> > +vhost_user_fs=""
> > kvm="no"
> > hax="no"
> > hvf="no"
> > @@ -1316,6 +1317,10 @@ for opt do
> >;;
> >--enable-vhost-vsock) vhost_vsock="yes"
> >;;
> > + --disable-vhost-user-fs) vhost_user_fs="no"
> > + ;;
> > + --enable-vhost-user-fs) vhost_user_fs="yes"
> > + ;;
> >--disable-opengl) opengl="no"
> >;;
> >--enable-opengl) opengl="yes"
> > @@ -2269,6 +2274,10 @@ test "$vhost_crypto" = "" && vhost_crypto=$vhost_user
> > if test "$vhost_crypto" = "yes" && test "$vhost_user" = "no"; then
> >error_exit "--enable-vhost-crypto requires --enable-vhost-user"
> > fi
> > +test "$vhost_user_fs" = "" && vhost_user_fs=$vhost_user
> > +if test "$vhost_user_fs" = "yes" && test "$vhost_user" = "no"; then
> > + error_exit "--enable-vhost-user-fs requires --enable-vhost-user"
> > +fi
> >
> > # OR the vhost-kernel and vhost-user values for simplicity
> > if test "$vhost_net" = ""; then
> > @@ -6425,6 +6434,7 @@ echo "vhost-crypto support $vhost_crypto"
> > echo "vhost-scsi support $vhost_scsi"
> > echo "vhost-vsock support $vhost_vsock"
> > echo "vhost-user support $vhost_user"
> > +echo "vhost-user-fs support $vhost_user_fs"
> > echo "Trace backends$trace_backends"
> > if have_backend "simple"; then
> > echo "Trace output file $trace_file-"
> > @@ -6921,6 +6931,9 @@ fi
> > if test "$vhost_user" = "yes" ; then
> >echo "CONFIG_VHOST_USER=y" >> $config_host_mak
> > fi
> > +if test "$vhost_user_fs" = "yes" ; then
> > + echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak
> > +fi
> > if test "$blobs" = "yes" ; then
> >echo "INSTALL_BLOBS=yes" >> $config_host_mak
> > fi
> > diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> > index 964ce78607..47ffbf22c4 100644
> > --- a/hw/virtio/Makefile.objs
> > +++ b/hw/virtio/Makefile.objs
> > @@ -11,6 +11,7 @@ common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
> > common-obj-$(CONFIG_VIRTIO_MMIO) += virtio-mmio.o
> > obj-$(CONFIG_VIRTIO_BALLOON) += virtio-balloon.o
> > obj-$(CONFIG_VIRTIO_CRYPTO) += virtio-crypto.o
> > +obj-$(CONFIG_VHOST_USER_FS) += vhost-user-fs.o
> > obj-$(call land,$(CONFIG_VIRTIO_CRYPTO),$(CONFIG_VIRTIO_PCI)) +=
> > virtio-crypto-pci.o
> > obj-$(CONFIG_VIRTIO_PMEM) += virtio-pmem.o
> > common-obj-$(call land,$(CONFIG_VIRTIO_PMEM),$(CONFIG_VIRTIO_PCI)) +=
> > virtio-pmem-pci.o
> > diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
> > new file mode 100644
> > index 00..2753c2c07a
> > --- /dev/null
> > +++ b/hw/virtio/vhost-user-fs.c
> > @@ -0,0 +1,297 @@
> > +/*
> > + * Vhost-user filesystem virtio device
> > + *
> > + * Copyright 2018 Red Hat, Inc.
> > + *
> > + * Authors:
> > + * Stefan Hajnoczi
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > + * (at your option) any later version. See the COPYING file in the
> > + * top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include
> > +#include "standard-headers/linux/virtio_fs.h"
> > +#include "qapi/error.h"
> > +#include "hw/virtio/virtio-bus.h"
> > +#include "hw/virtio/virtio-access.h"
> > +#include "qemu/error-report.h"
> > +#include "hw/virtio/vhost-user-fs.h"
> > +#include "monitor/monitor.h"
> > +
> > +static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
> > +{
> > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > +struct virtio_fs_config fscfg = {};
> > +
> > +memcpy((char *)fscfg.tag, fs->conf.tag,
> > + MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
> > +
> > +virtio_stl_p(vdev, _queues, fs->conf.num_queues);
> > +
> > +memcpy(config, , sizeof(fscfg));
> > +}
> > +
> > +static void vuf_start(VirtIODevice *vdev)
> > +{
Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
* Michael S. Tsirkin (m...@redhat.com) wrote:
> On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert"
> > +/* Hiprio queue */
> > +virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
> >
>
> Weird, spec patch v6 says:
>
> +\item[0] hiprio
> +\item[1\ldots n] request queues
>
> where's the Notifications queue coming from?
Oops, that's a left over from when we used to have a notification queue;
all the other parts of it are gone.
Dave
> > +/* Request queues */
> > +for (i = 0; i < fs->conf.num_queues; i++) {
> > +virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
> > +}
> > +
> > +/* 1 high prio queue, plus the number configured */
> > +fs->vhost_dev.nvqs = 1 + fs->conf.num_queues;
> > +fs->vhost_dev.vqs = g_new0(struct vhost_virtqueue, fs->vhost_dev.nvqs);
> > +ret = vhost_dev_init(>vhost_dev, >vhost_user,
> > + VHOST_BACKEND_TYPE_USER, 0);
> > +if (ret < 0) {
> > +error_setg_errno(errp, -ret, "vhost_dev_init failed");
> > +goto err_virtio;
> > +}
> > +
> > +return;
> > +
> > +err_virtio:
> > +vhost_user_cleanup(>vhost_user);
> > +virtio_cleanup(vdev);
> > +g_free(fs->vhost_dev.vqs);
> > +return;
> > +}
> > +
> > +static void vuf_device_unrealize(DeviceState *dev, Error **errp)
> > +{
> > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > +
> > +/* This will stop vhost backend if appropriate. */
> > +vuf_set_status(vdev, 0);
> > +
> > +vhost_dev_cleanup(>vhost_dev);
> > +
> > +vhost_user_cleanup(>vhost_user);
> > +
> > +virtio_cleanup(vdev);
> > +g_free(fs->vhost_dev.vqs);
> > +fs->vhost_dev.vqs = NULL;
> > +}
> > +
> > +static const VMStateDescription vuf_vmstate = {
> > +.name = "vhost-user-fs",
> > +.unmigratable = 1,
> > +};
> > +
> > +static Property vuf_properties[] = {
> > +DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev),
> > +DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag),
> > +DEFINE_PROP_UINT16("num-queues", VHostUserFS, conf.num_queues, 1),
> > +DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
> > +DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
> > +DEFINE_PROP_END_OF_LIST(),
> > +};
> > +
> > +static void vuf_class_init(ObjectClass *klass, void *data)
> > +{
> > +DeviceClass *dc = DEVICE_CLASS(klass);
> > +VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> > +
> > +dc->props = vuf_properties;
> > +dc->vmsd = _vmstate;
> > +set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
> > +vdc->realize = vuf_device_realize;
> > +vdc->unrealize = vuf_device_unrealize;
> > +vdc->get_features = vuf_get_features;
> > +vdc->get_config = vuf_get_config;
> > +vdc->set_status = vuf_set_status;
> > +vdc->guest_notifier_mask = vuf_guest_notifier_mask;
> > +vdc->guest_notifier_pending = vuf_guest_notifier_pending;
> > +}
> > +
> > +static const TypeInfo vuf_info = {
> > +.name = TYPE_VHOST_USER_FS,
> > +.parent = TYPE_VIRTIO_DEVICE,
> > +.instance_size = sizeof(VHostUserFS),
> > +.class_init = vuf_class_init,
> > +};
> > +
> > +static void vuf_register_types(void)
> > +{
> > +type_register_static(_info);
> > +}
> > +
> > +type_init(vuf_register_types)
> > diff --git a/include/hw/virtio/vhost-user-fs.h
> > b/include/hw/virtio/vhost-user-fs.h
> > new file mode 100644
> > index 00..d07ab134b9
> > --- /dev/null
> > +++ b/include/hw/virtio/vhost-user-fs.h
> > @@ -0,0 +1,45 @@
> > +/*
> > + * Vhost-user filesystem virtio device
> > + *
> > + * Copyright 2018 Red Hat, Inc.
> > + *
> > + * Authors:
> > + * Stefan Hajnoczi
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > + * (at your option) any later version. See the COPYING file in the
> > + * top-level directory.
> > + */
> > +
> > +#ifndef _QEMU_VHOST_USER_FS_H
> > +#define _QEMU_VHOST_USER_FS_H
> > +
> > +#include "hw/virtio/virtio.h"
> > +#include "hw/virtio/vhost.h"
> > +#include "hw/virtio/vhost-user.h"
> > +#include "chardev/char-fe.h"
> > +
> > +#define TYPE_VHOST_USER_FS "x-vhost-user-fs-device"
> > +#define VHOST_USER_FS(obj) \
> > +OBJECT_CHECK(VHostUserFS, (obj), TYPE_VHOST_USER_FS)
> > +
> > +typedef struct {
> > +CharBackend chardev;
> > +char *tag;
> > +uint16_t num_queues;
> > +uint16_t queue_size;
> > +char *vhostfd;
> > +} VHostUserFSConf;
> > +
> > +typedef struct {
> > +/*< private >*/
> > +VirtIODevice parent;
> > +VHostUserFSConf conf;
> > +struct vhost_virtqueue *vhost_vqs;
> > +struct vhost_dev vhost_dev;
> > +VhostUserState vhost_user;
> > +
> > +/*< public >*/
> > +} VHostUserFS;
> > +
> > +#endif /* _QEMU_VHOST_USER_FS_H */
> > diff --git a/include/standard-headers/linux/virtio_fs.h
> > b/include/standard-headers/linux/virtio_fs.h
Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
* Cornelia Huck (coh...@redhat.com) wrote:
> On Sun, 18 Aug 2019 07:08:31 -0400
> "Michael S. Tsirkin" wrote:
>
> > On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git)
> > wrote:
> > > From: "Dr. David Alan Gilbert"
> > >
> > > The virtio-fs virtio device provides shared file system access using
> > > the FUSE protocol carried ovew virtio.
> > > The actual file server is implemented in an external vhost-user-fs device
> > > backend process.
> > >
> > > Signed-off-by: Stefan Hajnoczi
> > > Signed-off-by: Sebastien Boeuf
> > > Signed-off-by: Dr. David Alan Gilbert
> > > ---
> > > configure | 13 +
> > > hw/virtio/Makefile.objs | 1 +
> > > hw/virtio/vhost-user-fs.c | 297
> > > include/hw/virtio/vhost-user-fs.h | 45 +++
> > > include/standard-headers/linux/virtio_fs.h | 41 +++
> > > include/standard-headers/linux/virtio_ids.h | 1 +
> > > 6 files changed, 398 insertions(+)
> > > create mode 100644 hw/virtio/vhost-user-fs.c
> > > create mode 100644 include/hw/virtio/vhost-user-fs.h
> > > create mode 100644 include/standard-headers/linux/virtio_fs.h
>
> > > diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
> > > new file mode 100644
> > > index 00..2753c2c07a
> > > --- /dev/null
> > > +++ b/hw/virtio/vhost-user-fs.c
> > > @@ -0,0 +1,297 @@
> > > +/*
> > > + * Vhost-user filesystem virtio device
> > > + *
> > > + * Copyright 2018 Red Hat, Inc.
> > > + *
> > > + * Authors:
> > > + * Stefan Hajnoczi
> > > + *
> > > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > > + * (at your option) any later version. See the COPYING file in the
> > > + * top-level directory.
> > > + */
> > > +
> > > +#include "qemu/osdep.h"
> > > +#include
> > > +#include "standard-headers/linux/virtio_fs.h"
> > > +#include "qapi/error.h"
> > > +#include "hw/virtio/virtio-bus.h"
> > > +#include "hw/virtio/virtio-access.h"
> > > +#include "qemu/error-report.h"
> > > +#include "hw/virtio/vhost-user-fs.h"
> > > +#include "monitor/monitor.h"
>
> JFYI, this needs to include hw/qdev-properties.h as well on the latest
> code level. (As does the pci part.)
Thanks! Updated my local version.
Dave
> > > +
> > > +static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
> > > +{
> > > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > > +struct virtio_fs_config fscfg = {};
> > > +
> > > +memcpy((char *)fscfg.tag, fs->conf.tag,
> > > + MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
> > > +
> > > +virtio_stl_p(vdev, _queues, fs->conf.num_queues);
> > > +
> > > +memcpy(config, , sizeof(fscfg));
> > > +}
> > > +
> > > +static void vuf_start(VirtIODevice *vdev)
> > > +{
> > > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > > +BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> > > +VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> > > +int ret;
> > > +int i;
> > > +
> > > +if (!k->set_guest_notifiers) {
> > > +error_report("binding does not support guest notifiers");
> > > +return;
> > > +}
> > > +
> > > +ret = vhost_dev_enable_notifiers(>vhost_dev, vdev);
> > > +if (ret < 0) {
> > > +error_report("Error enabling host notifiers: %d", -ret);
> > > +return;
> > > +}
> > > +
> > > +ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true);
> > > +if (ret < 0) {
> > > +error_report("Error binding guest notifier: %d", -ret);
> > > +goto err_host_notifiers;
> > > +}
> > > +
> > > +fs->vhost_dev.acked_features = vdev->guest_features;
> > > +ret = vhost_dev_start(>vhost_dev, vdev);
> > > +if (ret < 0) {
> > > +error_report("Error starting vhost: %d", -ret);
> > > +goto err_guest_notifiers;
> > > +}
> > > +
> > > +/*
> > > + * guest_notifier_mask/pending not used yet, so just unmask
> > > + * everything here. virtio-pci will do the right thing by
> > > + * enabling/disabling irqfd.
>
> Referring to 'virtio-pci' seems a bit suspicious :) Should that be 'the
> transport'? (And 'the right thing' is not really self-explanatory...)
>
> (I have wired it up for virtio-ccw, but have not actually tried it out.
> Will send it out once I did.)
>
> > > + */
> > > +for (i = 0; i < fs->vhost_dev.nvqs; i++) {
> > > +vhost_virtqueue_mask(>vhost_dev, vdev, i, false);
> > > +}
> > > +
> > > +return;
> > > +
> > > +err_guest_notifiers:
> > > +k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
> > > +err_host_notifiers:
> > > +vhost_dev_disable_notifiers(>vhost_dev, vdev);
> > > +}
>
> (...)
>
> > > +static void vuf_device_realize(DeviceState *dev, Error **errp)
> > > +{
> > > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > > +unsigned int i;
> > > +size_t len;
> > > +int ret;
> >
Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
On Sun, 18 Aug 2019 07:08:31 -0400
"Michael S. Tsirkin" wrote:
> On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert"
> >
> > The virtio-fs virtio device provides shared file system access using
> > the FUSE protocol carried ovew virtio.
> > The actual file server is implemented in an external vhost-user-fs device
> > backend process.
> >
> > Signed-off-by: Stefan Hajnoczi
> > Signed-off-by: Sebastien Boeuf
> > Signed-off-by: Dr. David Alan Gilbert
> > ---
> > configure | 13 +
> > hw/virtio/Makefile.objs | 1 +
> > hw/virtio/vhost-user-fs.c | 297
> > include/hw/virtio/vhost-user-fs.h | 45 +++
> > include/standard-headers/linux/virtio_fs.h | 41 +++
> > include/standard-headers/linux/virtio_ids.h | 1 +
> > 6 files changed, 398 insertions(+)
> > create mode 100644 hw/virtio/vhost-user-fs.c
> > create mode 100644 include/hw/virtio/vhost-user-fs.h
> > create mode 100644 include/standard-headers/linux/virtio_fs.h
> > diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
> > new file mode 100644
> > index 00..2753c2c07a
> > --- /dev/null
> > +++ b/hw/virtio/vhost-user-fs.c
> > @@ -0,0 +1,297 @@
> > +/*
> > + * Vhost-user filesystem virtio device
> > + *
> > + * Copyright 2018 Red Hat, Inc.
> > + *
> > + * Authors:
> > + * Stefan Hajnoczi
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > + * (at your option) any later version. See the COPYING file in the
> > + * top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +#include
> > +#include "standard-headers/linux/virtio_fs.h"
> > +#include "qapi/error.h"
> > +#include "hw/virtio/virtio-bus.h"
> > +#include "hw/virtio/virtio-access.h"
> > +#include "qemu/error-report.h"
> > +#include "hw/virtio/vhost-user-fs.h"
> > +#include "monitor/monitor.h"
JFYI, this needs to include hw/qdev-properties.h as well on the latest
code level. (As does the pci part.)
> > +
> > +static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
> > +{
> > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > +struct virtio_fs_config fscfg = {};
> > +
> > +memcpy((char *)fscfg.tag, fs->conf.tag,
> > + MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
> > +
> > +virtio_stl_p(vdev, _queues, fs->conf.num_queues);
> > +
> > +memcpy(config, , sizeof(fscfg));
> > +}
> > +
> > +static void vuf_start(VirtIODevice *vdev)
> > +{
> > +VHostUserFS *fs = VHOST_USER_FS(vdev);
> > +BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> > +VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> > +int ret;
> > +int i;
> > +
> > +if (!k->set_guest_notifiers) {
> > +error_report("binding does not support guest notifiers");
> > +return;
> > +}
> > +
> > +ret = vhost_dev_enable_notifiers(>vhost_dev, vdev);
> > +if (ret < 0) {
> > +error_report("Error enabling host notifiers: %d", -ret);
> > +return;
> > +}
> > +
> > +ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true);
> > +if (ret < 0) {
> > +error_report("Error binding guest notifier: %d", -ret);
> > +goto err_host_notifiers;
> > +}
> > +
> > +fs->vhost_dev.acked_features = vdev->guest_features;
> > +ret = vhost_dev_start(>vhost_dev, vdev);
> > +if (ret < 0) {
> > +error_report("Error starting vhost: %d", -ret);
> > +goto err_guest_notifiers;
> > +}
> > +
> > +/*
> > + * guest_notifier_mask/pending not used yet, so just unmask
> > + * everything here. virtio-pci will do the right thing by
> > + * enabling/disabling irqfd.
Referring to 'virtio-pci' seems a bit suspicious :) Should that be 'the
transport'? (And 'the right thing' is not really self-explanatory...)
(I have wired it up for virtio-ccw, but have not actually tried it out.
Will send it out once I did.)
> > + */
> > +for (i = 0; i < fs->vhost_dev.nvqs; i++) {
> > +vhost_virtqueue_mask(>vhost_dev, vdev, i, false);
> > +}
> > +
> > +return;
> > +
> > +err_guest_notifiers:
> > +k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
> > +err_host_notifiers:
> > +vhost_dev_disable_notifiers(>vhost_dev, vdev);
> > +}
(...)
> > +static void vuf_device_realize(DeviceState *dev, Error **errp)
> > +{
> > +VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> > +VHostUserFS *fs = VHOST_USER_FS(dev);
> > +unsigned int i;
> > +size_t len;
> > +int ret;
> > +
> > +if (!fs->conf.chardev.chr) {
> > +error_setg(errp, "missing chardev");
> > +return;
> > +}
> > +
> > +if (!fs->conf.tag) {
> > +error_setg(errp, "missing tag property");
> > +return;
> > +}
> > +len = strlen(fs->conf.tag);
> > +if (len == 0) {
> > +error_setg(errp, "tag property cannot be
Re: [Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
On Fri, Aug 16, 2019 at 03:33:20PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert"
>
> The virtio-fs virtio device provides shared file system access using
> the FUSE protocol carried ovew virtio.
> The actual file server is implemented in an external vhost-user-fs device
> backend process.
>
> Signed-off-by: Stefan Hajnoczi
> Signed-off-by: Sebastien Boeuf
> Signed-off-by: Dr. David Alan Gilbert
> ---
> configure | 13 +
> hw/virtio/Makefile.objs | 1 +
> hw/virtio/vhost-user-fs.c | 297
> include/hw/virtio/vhost-user-fs.h | 45 +++
> include/standard-headers/linux/virtio_fs.h | 41 +++
> include/standard-headers/linux/virtio_ids.h | 1 +
> 6 files changed, 398 insertions(+)
> create mode 100644 hw/virtio/vhost-user-fs.c
> create mode 100644 include/hw/virtio/vhost-user-fs.h
> create mode 100644 include/standard-headers/linux/virtio_fs.h
>
> diff --git a/configure b/configure
> index 714e7fb6a1..e7e33ee783 100755
> --- a/configure
> +++ b/configure
> @@ -382,6 +382,7 @@ vhost_crypto=""
> vhost_scsi=""
> vhost_vsock=""
> vhost_user=""
> +vhost_user_fs=""
> kvm="no"
> hax="no"
> hvf="no"
> @@ -1316,6 +1317,10 @@ for opt do
>;;
>--enable-vhost-vsock) vhost_vsock="yes"
>;;
> + --disable-vhost-user-fs) vhost_user_fs="no"
> + ;;
> + --enable-vhost-user-fs) vhost_user_fs="yes"
> + ;;
>--disable-opengl) opengl="no"
>;;
>--enable-opengl) opengl="yes"
> @@ -2269,6 +2274,10 @@ test "$vhost_crypto" = "" && vhost_crypto=$vhost_user
> if test "$vhost_crypto" = "yes" && test "$vhost_user" = "no"; then
>error_exit "--enable-vhost-crypto requires --enable-vhost-user"
> fi
> +test "$vhost_user_fs" = "" && vhost_user_fs=$vhost_user
> +if test "$vhost_user_fs" = "yes" && test "$vhost_user" = "no"; then
> + error_exit "--enable-vhost-user-fs requires --enable-vhost-user"
> +fi
>
> # OR the vhost-kernel and vhost-user values for simplicity
> if test "$vhost_net" = ""; then
> @@ -6425,6 +6434,7 @@ echo "vhost-crypto support $vhost_crypto"
> echo "vhost-scsi support $vhost_scsi"
> echo "vhost-vsock support $vhost_vsock"
> echo "vhost-user support $vhost_user"
> +echo "vhost-user-fs support $vhost_user_fs"
> echo "Trace backends$trace_backends"
> if have_backend "simple"; then
> echo "Trace output file $trace_file-"
> @@ -6921,6 +6931,9 @@ fi
> if test "$vhost_user" = "yes" ; then
>echo "CONFIG_VHOST_USER=y" >> $config_host_mak
> fi
> +if test "$vhost_user_fs" = "yes" ; then
> + echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak
> +fi
> if test "$blobs" = "yes" ; then
>echo "INSTALL_BLOBS=yes" >> $config_host_mak
> fi
> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> index 964ce78607..47ffbf22c4 100644
> --- a/hw/virtio/Makefile.objs
> +++ b/hw/virtio/Makefile.objs
> @@ -11,6 +11,7 @@ common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
> common-obj-$(CONFIG_VIRTIO_MMIO) += virtio-mmio.o
> obj-$(CONFIG_VIRTIO_BALLOON) += virtio-balloon.o
> obj-$(CONFIG_VIRTIO_CRYPTO) += virtio-crypto.o
> +obj-$(CONFIG_VHOST_USER_FS) += vhost-user-fs.o
> obj-$(call land,$(CONFIG_VIRTIO_CRYPTO),$(CONFIG_VIRTIO_PCI)) +=
> virtio-crypto-pci.o
> obj-$(CONFIG_VIRTIO_PMEM) += virtio-pmem.o
> common-obj-$(call land,$(CONFIG_VIRTIO_PMEM),$(CONFIG_VIRTIO_PCI)) +=
> virtio-pmem-pci.o
> diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
> new file mode 100644
> index 00..2753c2c07a
> --- /dev/null
> +++ b/hw/virtio/vhost-user-fs.c
> @@ -0,0 +1,297 @@
> +/*
> + * Vhost-user filesystem virtio device
> + *
> + * Copyright 2018 Red Hat, Inc.
> + *
> + * Authors:
> + * Stefan Hajnoczi
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or
> + * (at your option) any later version. See the COPYING file in the
> + * top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include
> +#include "standard-headers/linux/virtio_fs.h"
> +#include "qapi/error.h"
> +#include "hw/virtio/virtio-bus.h"
> +#include "hw/virtio/virtio-access.h"
> +#include "qemu/error-report.h"
> +#include "hw/virtio/vhost-user-fs.h"
> +#include "monitor/monitor.h"
> +
> +static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
> +{
> +VHostUserFS *fs = VHOST_USER_FS(vdev);
> +struct virtio_fs_config fscfg = {};
> +
> +memcpy((char *)fscfg.tag, fs->conf.tag,
> + MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
> +
> +virtio_stl_p(vdev, _queues, fs->conf.num_queues);
> +
> +memcpy(config, , sizeof(fscfg));
> +}
> +
> +static void vuf_start(VirtIODevice *vdev)
> +{
> +VHostUserFS *fs = VHOST_USER_FS(vdev);
> +BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> +VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
> +int ret;
> +int i;
> +
> +if (!k->set_guest_notifiers) {
> +error_report("binding does not support guest notifiers");
> +
[Qemu-devel] [PATCH 1/2] virtio: add vhost-user-fs base device
From: "Dr. David Alan Gilbert"
The virtio-fs virtio device provides shared file system access using
the FUSE protocol carried ovew virtio.
The actual file server is implemented in an external vhost-user-fs device
backend process.
Signed-off-by: Stefan Hajnoczi
Signed-off-by: Sebastien Boeuf
Signed-off-by: Dr. David Alan Gilbert
---
configure | 13 +
hw/virtio/Makefile.objs | 1 +
hw/virtio/vhost-user-fs.c | 297
include/hw/virtio/vhost-user-fs.h | 45 +++
include/standard-headers/linux/virtio_fs.h | 41 +++
include/standard-headers/linux/virtio_ids.h | 1 +
6 files changed, 398 insertions(+)
create mode 100644 hw/virtio/vhost-user-fs.c
create mode 100644 include/hw/virtio/vhost-user-fs.h
create mode 100644 include/standard-headers/linux/virtio_fs.h
diff --git a/configure b/configure
index 714e7fb6a1..e7e33ee783 100755
--- a/configure
+++ b/configure
@@ -382,6 +382,7 @@ vhost_crypto=""
vhost_scsi=""
vhost_vsock=""
vhost_user=""
+vhost_user_fs=""
kvm="no"
hax="no"
hvf="no"
@@ -1316,6 +1317,10 @@ for opt do
;;
--enable-vhost-vsock) vhost_vsock="yes"
;;
+ --disable-vhost-user-fs) vhost_user_fs="no"
+ ;;
+ --enable-vhost-user-fs) vhost_user_fs="yes"
+ ;;
--disable-opengl) opengl="no"
;;
--enable-opengl) opengl="yes"
@@ -2269,6 +2274,10 @@ test "$vhost_crypto" = "" && vhost_crypto=$vhost_user
if test "$vhost_crypto" = "yes" && test "$vhost_user" = "no"; then
error_exit "--enable-vhost-crypto requires --enable-vhost-user"
fi
+test "$vhost_user_fs" = "" && vhost_user_fs=$vhost_user
+if test "$vhost_user_fs" = "yes" && test "$vhost_user" = "no"; then
+ error_exit "--enable-vhost-user-fs requires --enable-vhost-user"
+fi
# OR the vhost-kernel and vhost-user values for simplicity
if test "$vhost_net" = ""; then
@@ -6425,6 +6434,7 @@ echo "vhost-crypto support $vhost_crypto"
echo "vhost-scsi support $vhost_scsi"
echo "vhost-vsock support $vhost_vsock"
echo "vhost-user support $vhost_user"
+echo "vhost-user-fs support $vhost_user_fs"
echo "Trace backends$trace_backends"
if have_backend "simple"; then
echo "Trace output file $trace_file-"
@@ -6921,6 +6931,9 @@ fi
if test "$vhost_user" = "yes" ; then
echo "CONFIG_VHOST_USER=y" >> $config_host_mak
fi
+if test "$vhost_user_fs" = "yes" ; then
+ echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak
+fi
if test "$blobs" = "yes" ; then
echo "INSTALL_BLOBS=yes" >> $config_host_mak
fi
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 964ce78607..47ffbf22c4 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -11,6 +11,7 @@ common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
common-obj-$(CONFIG_VIRTIO_MMIO) += virtio-mmio.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio-balloon.o
obj-$(CONFIG_VIRTIO_CRYPTO) += virtio-crypto.o
+obj-$(CONFIG_VHOST_USER_FS) += vhost-user-fs.o
obj-$(call land,$(CONFIG_VIRTIO_CRYPTO),$(CONFIG_VIRTIO_PCI)) +=
virtio-crypto-pci.o
obj-$(CONFIG_VIRTIO_PMEM) += virtio-pmem.o
common-obj-$(call land,$(CONFIG_VIRTIO_PMEM),$(CONFIG_VIRTIO_PCI)) +=
virtio-pmem-pci.o
diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
new file mode 100644
index 00..2753c2c07a
--- /dev/null
+++ b/hw/virtio/vhost-user-fs.c
@@ -0,0 +1,297 @@
+/*
+ * Vhost-user filesystem virtio device
+ *
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Authors:
+ * Stefan Hajnoczi
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version. See the COPYING file in the
+ * top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include
+#include "standard-headers/linux/virtio_fs.h"
+#include "qapi/error.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+#include "qemu/error-report.h"
+#include "hw/virtio/vhost-user-fs.h"
+#include "monitor/monitor.h"
+
+static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+VHostUserFS *fs = VHOST_USER_FS(vdev);
+struct virtio_fs_config fscfg = {};
+
+memcpy((char *)fscfg.tag, fs->conf.tag,
+ MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
+
+virtio_stl_p(vdev, _queues, fs->conf.num_queues);
+
+memcpy(config, , sizeof(fscfg));
+}
+
+static void vuf_start(VirtIODevice *vdev)
+{
+VHostUserFS *fs = VHOST_USER_FS(vdev);
+BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+int ret;
+int i;
+
+if (!k->set_guest_notifiers) {
+error_report("binding does not support guest notifiers");
+return;
+}
+
+ret = vhost_dev_enable_notifiers(>vhost_dev, vdev);
+if (ret < 0) {
+error_report("Error enabling host notifiers: %d", -ret);
+return;
+}
+
+ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true);
+if (ret < 0) {
+error_report("Error binding guest notifier: %d", -ret);
+
