Commit Graph

25 Commits

Author SHA1 Message Date
Jonah Palmer
b937fa8963 vhost/vhost-user: Add VIRTIO_F_NOTIFICATION_DATA to vhost feature bits
Add support for the VIRTIO_F_NOTIFICATION_DATA feature across a variety
of vhost devices.

The inclusion of VIRTIO_F_NOTIFICATION_DATA in the feature bits arrays
for these devices ensures that the backend is capable of offering and
providing support for this feature, and that it can be disabled if the
backend does not support it.

Tested-by: Lei Yang <leiyang@redhat.com>
Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <20240315165557.26942-6-jonah.palmer@oracle.com>
Acked-by: Srujana Challa <schalla@marvell.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-01 14:56:23 -04:00
Richard Henderson
ca02a17054 hw/virtio: Constify VMState
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231221031652.119827-61-richard.henderson@linaro.org>
2023-12-30 07:38:06 +11:00
Hanna Czenczek
bca3e2a138 vhost-user-fs: Implement internal migration
A virtio-fs device's VM state consists of:
- the virtio device (vring) state (VMSTATE_VIRTIO_DEVICE)
- the back-end's (virtiofsd's) internal state

We get/set the latter via the new vhost operations to transfer migratory
state.  It is its own dedicated subsection, so that for external
migration, it can be disabled.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20231016134243.68248-8-hreitz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-11-07 03:39:10 -05:00
Alex Bennée
7e8094f0df hw/virtio: fix typo in VIRTIO_CONFIG_IRQ_IDX comments
Fixes: 544f0278af (virtio: introduce macro VIRTIO_CONFIG_IRQ_IDX)
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230710153522.3469097-4-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-07-10 18:59:32 -04:00
Akihiko Odaki
331acddc87 vhost-user-fs: Back up vqs before cleaning up vhost_dev
vhost_dev_cleanup() clears vhost_dev so back up its vqs member to free
the memory pointed by the member.

Fixes: 98fc1ada4c ("virtio: add vhost-user-fs base device")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230130140225.77964-1-akihiko.odaki@daynix.com>
2023-02-09 10:21:11 -05:00
Cindy Lu
544f0278af virtio: introduce macro VIRTIO_CONFIG_IRQ_IDX
To support configure interrupt for vhost-vdpa
Introduce VIRTIO_CONFIG_IRQ_IDX -1 as configure interrupt's queue index,
Then we can reuse the functions guest_notifier_mask and guest_notifier_pending.
Add the check of queue index in these drivers, if the driver does not support
configure interrupt, the function will just return

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20221222070451.936503-2-lulu@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-01-08 01:54:22 -05:00
Stefano Garzarella
4daa5054c5 vhost: enable vrings in vhost_dev_start() for vhost-user devices
Commit 02b61f38d3 ("hw/virtio: incorporate backend features in features")
properly negotiates VHOST_USER_F_PROTOCOL_FEATURES with the vhost-user
backend, but we forgot to enable vrings as specified in
docs/interop/vhost-user.rst:

    If ``VHOST_USER_F_PROTOCOL_FEATURES`` has not been negotiated, the
    ring starts directly in the enabled state.

    If ``VHOST_USER_F_PROTOCOL_FEATURES`` has been negotiated, the ring is
    initialized in a disabled state and is enabled by
    ``VHOST_USER_SET_VRING_ENABLE`` with parameter 1.

Some vhost-user front-ends already did this by calling
vhost_ops.vhost_set_vring_enable() directly:
- backends/cryptodev-vhost.c
- hw/net/virtio-net.c
- hw/virtio/vhost-user-gpio.c

But most didn't do that, so we would leave the vrings disabled and some
backends would not work. We observed this issue with the rust version of
virtiofsd [1], which uses the event loop [2] provided by the
vhost-user-backend crate where requests are not processed if vring is
not enabled.

Let's fix this issue by enabling the vrings in vhost_dev_start() for
vhost-user front-ends that don't already do this directly. Same thing
also in vhost_dev_stop() where we disable vrings.

[1] https://gitlab.com/virtio-fs/virtiofsd
[2] https://github.com/rust-vmm/vhost/blob/240fc2966/crates/vhost-user-backend/src/event_loop.rs#L217

Fixes: 02b61f38d3 ("hw/virtio: incorporate backend features in features")
Reported-by: German Maglione <gmaglione@redhat.com>
Tested-by: German Maglione <gmaglione@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20221123131630.52020-1-sgarzare@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20221130112439.2527228-3-alex.bennee@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-12-01 02:30:04 -05:00
Stefano Garzarella
562a7d23bf vhost: mask VIRTIO_F_RING_RESET for vhost and vhost-user devices
Commit 69e1c14aa2 ("virtio: core: vq reset feature negotation support")
enabled VIRTIO_F_RING_RESET by default for all virtio devices.

This feature is not currently emulated by QEMU, so for vhost and
vhost-user devices we need to make sure it is supported by the offloaded
device emulation (in-kernel or in another process).
To do this we need to add VIRTIO_F_RING_RESET to the features bitmap
passed to vhost_get_features(). This way it will be masked if the device
does not support it.

This issue was initially discovered with vhost-vsock and vhost-user-vsock,
and then also tested with vhost-user-rng which confirmed the same issue.
They fail when sending features through VHOST_SET_FEATURES ioctl or
VHOST_USER_SET_FEATURES message, since VIRTIO_F_RING_RESET is negotiated
by the guest (Linux >= v6.0), but not supported by the device.

Fixes: 69e1c14aa2 ("virtio: core: vq reset feature negotation support")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1318
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20221121101101.29400-1-sgarzare@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Acked-by: Jason Wang <jasowang@redhat.com>
2022-11-22 05:19:00 -05:00
Alex Bennée
259d69c00b hw/virtio: introduce virtio_device_should_start
The previous fix to virtio_device_started revealed a problem in its
use by both the core and the device code. The core code should be able
to handle the device "starting" while the VM isn't running to handle
the restoration of migration state. To solve this duel use introduce a
new helper for use by the vhost-user backends who all use it to feed a
should_start variable.

We can also pick up a change vhost_user_blk_set_status while we are at
it which follows the same pattern.

Fixes: 9f6bcfd99f (hw/virtio: move vm_running check to virtio_device_started)
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Message-Id: <20221107121407.1010913-1-alex.bennee@linaro.org>
2022-11-07 14:08:18 -05:00
Alex Bennée
b8f3e6a18d hw/virtio: move vhd->started check into helper and add FIXME
The `started` field is manipulated internally within the vhost code
except for one place, vhost-user-blk via f5b22d06fb (vhost: recheck
dev state in the vhost_migration_log routine). Mark that as a FIXME
because it introduces a potential race. I think the referenced fix
should be tracking its state locally.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220802095010.3330793-12-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwittz@nutanix.com>
2022-10-07 09:41:51 -04:00
Alex Bennée
9f6bcfd99f hw/virtio: move vm_running check to virtio_device_started
All the boilerplate virtio code does the same thing (or should at
least) of checking to see if the VM is running before attempting to
start VirtIO. Push the logic up to the common function to avoid
getting a copy and paste wrong.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220802095010.3330793-11-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-07 09:41:51 -04:00
Jonah Palmer
c255488d67 virtio: add vhost support for virtio devices
This patch adds a get_vhost() callback function for VirtIODevices that
returns the device's corresponding vhost_dev structure, if the vhost
device is running. This patch also adds a vhost_started flag for
VirtIODevices.

Previously, a VirtIODevice wouldn't be able to tell if its corresponding
vhost device was active or not.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1648819405-25696-3-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-16 04:38:40 -04:00
Jonah Palmer
3857cd5c7f virtio: drop name parameter for virtio_init()
This patch drops the name parameter for the virtio_init function.

The pair between the numeric device ID and the string device ID
(name) of a virtio device already exists, but not in a way that
lets us map between them.

This patch lets us do this and removes the need for the name
parameter in the virtio_init function.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1648819405-25696-2-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-16 04:38:40 -04:00
Michael S. Tsirkin
a882b57123 Revert "virtio: introduce macro IRTIO_CONFIG_IRQ_IDX"
This reverts commit bf1d85c166.

Fixes: bf1d85c166 ("virtio: introduce macro IRTIO_CONFIG_IRQ_IDX")
Cc: "Cindy Lu" <lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-10 16:02:54 -05:00
Cindy Lu
bf1d85c166 virtio: introduce macro IRTIO_CONFIG_IRQ_IDX
To support configure interrupt for vhost-vdpa
Introduce VIRTIO_CONFIG_IRQ_IDX -1 as configure interrupt's queue index,
Then we can reuse the functions guest_notifier_mask and guest_notifier_pending.
Add the check of queue index in these drivers, if the driver does not support
configure interrupt, the function will just return

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-2-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-06 06:11:39 -05:00
Kevin Wolf
a6945f2287 vhost: Add Error parameter to vhost_dev_init()
This allows callers to return better error messages instead of making
one up while the real error ends up on stderr. Most callers can
immediately make use of this because they already have an Error
parameter themselves. The others just keep printing the error with
error_report_err().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210609154658.350308-2-kwolf@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-30 13:15:44 +02:00
Anton Kuchin
ace66791cd vhost-user-fs: fix features handling
Make virtio-fs take into account server capabilities.

Just returning requested features assumes they all of then are implemented
by server and results in setting unsupported configuration if some of them
are absent.

Signed-off-by: Anton Kuchin <antonkuchin@yandex-team.ru>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  With changes suggested by Stefan
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-04-13 16:13:41 +01:00
Laszlo Ersek
6da32fe5ef vhost-user-fs: add the "bootindex" property
virtio-fs qualifies as a bootable device minimally under OVMF, but
currently the necessary "bootindex" property is missing. Add the property.

Expose the property only in the PCI device, for now. There is no boot
support for virtiofs on s390x (ccw) for the time being [1] [2], so leave
the CCW device unchanged. Add the property to the base device still,
because adding the alias to the CCW device later will be easier this way
[3].

[1] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg01745.html
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg01870.html
[3] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg01751.html

Example OpenFirmware device path for the "vhost-user-fs-pci" device in the
"bootorder" fw_cfg file:

  /pci@i0cf8/pci-bridge@1,6/pci1af4,105a@0/filesystem@0

Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Ján Tomko <jtomko@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: virtio-fs@redhat.com
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210112131603.12686-1-lersek@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-01-13 09:06:37 -05:00
Eduardo Habkost
ce35e2295e qdev: Move softmmu properties to qdev-properties-system.h
Move the property types and property macros implemented in
qdev-properties-system.c to a new qdev-properties-system.h
header.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20201211220529.2290218-16-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-12-18 15:20:17 -05:00
Markus Armbruster
b69c3c21a5 qdev: Unrealize must not fail
Devices may have component devices and buses.

Device realization may fail.  Realization is recursive: a device's
realize() method realizes its components, and device_set_realized()
realizes its buses (which should in turn realize the devices on that
bus, except bus_set_realized() doesn't implement that, yet).

When realization of a component or bus fails, we need to roll back:
unrealize everything we realized so far.  If any of these unrealizes
failed, the device would be left in an inconsistent state.  Must not
happen.

device_set_realized() lets it happen: it ignores errors in the roll
back code starting at label child_realize_fail.

Since realization is recursive, unrealization must be recursive, too.
But how could a partly failed unrealize be rolled back?  We'd have to
re-realize, which can fail.  This design is fundamentally broken.

device_set_realized() does not roll back at all.  Instead, it keeps
unrealizing, ignoring further errors.

It can screw up even for a device with no buses: if the lone
dc->unrealize() fails, it still unregisters vmstate, and calls
listeners' unrealize() callback.

bus_set_realized() does not roll back either.  Instead, it stops
unrealizing.

Fortunately, no unrealize method can fail, as we'll see below.

To fix the design error, drop parameter @errp from all the unrealize
methods.

Any unrealize method that uses @errp now needs an update.  This leads
us to unrealize() methods that can fail.  Merely passing it to another
unrealize method cannot cause failure, though.  Here are the ones that
do other things with @errp:

* virtio_serial_device_unrealize()

  Fails when qbus_set_hotplug_handler() fails, but still does all the
  other work.  On failure, the device would stay realized with its
  resources completely gone.  Oops.  Can't happen, because
  qbus_set_hotplug_handler() can't actually fail here.  Pass
  &error_abort to qbus_set_hotplug_handler() instead.

* hw/ppc/spapr_drc.c's unrealize()

  Fails when object_property_del() fails, but all the other work is
  already done.  On failure, the device would stay realized with its
  vmstate registration gone.  Oops.  Can't happen, because
  object_property_del() can't actually fail here.  Pass &error_abort
  to object_property_del() instead.

* spapr_phb_unrealize()

  Fails and bails out when remove_drcs() fails, but other work is
  already done.  On failure, the device would stay realized with some
  of its resources gone.  Oops.  remove_drcs() fails only when
  chassis_from_bus()'s object_property_get_uint() fails, and it can't
  here.  Pass &error_abort to remove_drcs() instead.

Therefore, no unrealize method can fail before this patch.

device_set_realized()'s recursive unrealization via bus uses
object_property_set_bool().  Can't drop @errp there, so pass
&error_abort.

We similarly unrealize with object_property_set_bool() elsewhere,
always ignoring errors.  Pass &error_abort instead.

Several unrealize methods no longer handle errors from other unrealize
methods: virtio_9p_device_unrealize(),
virtio_input_device_unrealize(), scsi_qdev_unrealize(), ...
Much of the deleted error handling looks wrong anyway.

One unrealize methods no longer ignore such errors:
usb_ehci_pci_exit().

Several realize methods no longer ignore errors when rolling back:
v9fs_device_realize_common(), pci_qdev_unrealize(),
spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(),
virtio_device_realize().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-17-armbru@redhat.com>
2020-05-15 07:08:14 +02:00
Pan Nengyuan
2e5bc65935 vhost-user-fs: convert to the new virtio_delete_queue function
use the new virtio_delete_queue function to cleanup.

Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200225075554.10835-3-pannengyuan@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-25 08:32:45 -05:00
Pan Nengyuan
ba07cf5d3f vhost-user-fs: do delete virtio_queues in unrealize
Similar to other virtio device(https://patchwork.kernel.org/patch/11399237/), virtio queues forgot to delete in unrealize, and aslo error path in realize, this patch fix these memleaks, the leak stack is as follow:
Direct leak of 57344 byte(s) in 1 object(s) allocated from:
    #0 0x7f15784fb970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
    #1 0x7f157790849d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
    #2 0x55587a1bf859 in virtio_add_queue /mnt/sdb/qemu-new/qemu_test/qemu/hw/virtio/virtio.c:2333
    #3 0x55587a2071d5 in vuf_device_realize /mnt/sdb/qemu-new/qemu_test/qemu/hw/virtio/vhost-user-fs.c:212
    #4 0x55587a1ae360 in virtio_device_realize /mnt/sdb/qemu-new/qemu_test/qemu/hw/virtio/virtio.c:3531
    #5 0x55587a63fb7b in device_set_realized /mnt/sdb/qemu-new/qemu_test/qemu/hw/core/qdev.c:891
    #6 0x55587acf03f5 in property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:2238
    #7 0x55587acfce0d in object_property_set_qobject /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qobject.c:26
    #8 0x55587acf5c8c in object_property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:1390
    #9 0x55587a8e22a2 in pci_qdev_realize /mnt/sdb/qemu-new/qemu_test/qemu/hw/pci/pci.c:2095
    #10 0x55587a63fb7b in device_set_realized /mnt/sdb/qemu-new/qemu_test/qemu/hw/core/qdev.c:891
    #11 0x55587acf03f5 in property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:2238
    #12 0x55587acfce0d in object_property_set_qobject /mnt/sdb/qemu-new/qemu_test/qemu/qom/qom-qobject.c:26
    #13 0x55587acf5c8c in object_property_set_bool /mnt/sdb/qemu-new/qemu_test/qemu/qom/object.c:1390
    #14 0x55587a496d65 in qdev_device_add /mnt/sdb/qemu-new/qemu_test/qemu/qdev-monitor.c:679

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200225075554.10835-2-pannengyuan@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-25 08:32:45 -05:00
Marc-André Lureau
4f67d30b5e qdev: set properties with device_class_set_props()
The following patch will need to handle properties registration during
class_init time. Let's use a device_class_set_props() setter.

spatch --macro-file scripts/cocci-macro-file.h  --sp-file
./scripts/coccinelle/qdev-set-props.cocci --keep-comments --in-place
--dir .

@@
typedef DeviceClass;
DeviceClass *d;
expression val;
@@
- d->props = val
+ device_class_set_props(d, val)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-20-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:15 +01:00
Marc-André Lureau
7038573487 vhost-user-fs: remove "vhostfd" property
The property doesn't make much sense for a vhost-user device.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20191116112016.14872-1-marcandre.lureau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-12-13 10:38:58 +00:00
Dr. David Alan Gilbert
98fc1ada4c virtio: add vhost-user-fs base device
The virtio-fs virtio device provides shared file system access using
the FUSE protocol carried over virtio.
The actual file server is implemented in an external vhost-user-fs device
backend process.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190930105135.27244-3-dgilbert@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-05 17:43:55 -04:00