Commit Graph

182 Commits

Author SHA1 Message Date
Alex Bennée
6ca6d8ee9d hw/virtio: add vhost_user_[read|write] trace points
These are useful when trying to debug the initial vhost-user
negotiation, especially when it hard to get logging from the low level
library on the other side.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20220321153037.3622127-4-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2022-05-16 04:38:40 -04:00
Murilo Opsfelder Araujo
97252353c1 vhost-user: Use correct macro name TARGET_PPC64
The correct name of the macro is TARGET_PPC64.

Fixes: 27598393a2 ("Lift max memory slots limit imposed by vhost-user")
Reported-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: Peter Turschmid <peter.turschm@nutanix.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220503180108.34506-1-muriloo@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2022-05-05 15:36:16 -03:00
Kevin Wolf
a81d8d4a72 vhost-user: Don't pass file descriptor for VHOST_USER_REM_MEM_REG
The spec clarifies now that QEMU should not send a file descriptor in a
request to remove a memory region. Change it accordingly.

For libvhost-user, this is a bug fix that makes it compatible with
rust-vmm's implementation that doesn't send a file descriptor. Keep
accepting, but ignoring a file descriptor for compatibility with older
QEMU versions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220407133657.155281-4-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-05-04 15:55:23 +02:00
Marc-André Lureau
ff5927baa7 util: rename qemu_*block() socket functions
The qemu_*block() functions are meant to be be used with sockets (the
win32 implementation expects SOCKET)

Over time, those functions where used with Win32 SOCKET or
file-descriptors interchangeably. But for portability, they must only be
used with socket-like file-descriptors. FDs can use
g_unix_set_fd_nonblocking() instead.

Rename the functions with "socket" in the name to prevent bad usages.

This is effectively reverting commit f9e8cacc55 ("oslib-posix:
rename socket_set_nonblock() to qemu_set_nonblock()").

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-05-03 15:53:20 +04:00
Marc-André Lureau
8e3b0cbb72 Replace qemu_real_host_page variables with inlined functions
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00
Xueming Li
0b0af4d62f vhost-user: fix VirtQ notifier cleanup
When vhost-user device cleanup, remove notifier MR and munmaps notifier
address in the event-handling thread, VM CPU thread writing the notifier
in concurrent fails with an error of accessing invalid address. It
happens because MR is still being referenced and accessed in another
thread while the underlying notifier mmap address is being freed and
becomes invalid.

This patch calls RCU and munmap notifiers in the callback after the
memory flatview update finish.

Fixes: 44866521bd ("vhost-user: support registering external host notifiers")
Cc: qemu-stable@nongnu.org
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Message-Id: <20220207071929.527149-3-xuemingl@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-04 08:30:52 -05:00
Xueming Li
e867144b73 vhost-user: remove VirtQ notifier restore
Notifier set when vhost-user backend asks qemu to mmap an FD and
offset. When vhost-user backend restart or getting killed, VQ notifier
FD and mmap addresses become invalid. After backend restart, MR contains
the invalid address will be restored and fail on notifier access.

On the other hand, qemu should munmap the notifier, release underlying
hardware resources to enable backend restart and allocate hardware
notifier resources correctly.

Qemu shouldn't reference and use resources of disconnected backend.

This patch removes VQ notifier restore, uses the default vhost-user
notifier to avoid invalid address access.

After backend restart, the backend should ask qemu to install a hardware
notifier if needed.

Fixes: 44866521bd ("vhost-user: support registering external host notifiers")
Cc: qemu-stable@nongnu.org
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Message-Id: <20220207071929.527149-2-xuemingl@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-03-04 08:30:52 -05:00
Roman Kagan
025faa872b vhost-user: stick to -errno error return convention
VhostOps methods in user_ops are not very consistent in their error
returns: some return negated errno while others just -1.

Make sure all of them consistently return negated errno.  This also
helps error propagation from the functions being called inside.
Besides, this synchronizes the error return convention with the other
two vhost backends, kernel and vdpa, and will therefore allow for
consistent error propagation in the generic vhost code (in a followup
patch).

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Message-Id: <20211111153354.18807-9-rvkagan@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-07 05:19:55 -05:00
Xueming Li
a1ed9ef1de vhost-user: fix duplicated notifier MR init
In case of device resume after suspend, VQ notifier MR still valid.
Duplicated registrations explode memory block list and slow down device
resume.

Fixes: 44866521bd ("vhost-user: support registering external host notifiers")
Cc: tiwei.bie@intel.com
Cc: qemu-stable@nongnu.org
Cc: Yuwei Zhang <zhangyuwei.9149@bytedance.com>

Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Message-Id: <20211008080215.590292-1-xuemingl@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-10-20 04:37:55 -04:00
Yuwei Zhang
c6effa9cf5 hw/virtio: Add flatview update in vhost_user_cleanup()
Qemu will crash on vhost backend unexpected exit and re-connect                                                                          │
in some case due to access released memory.

Signed-off-by: Yuwei Zhang <zhangyuwei.9149@bytedance.com>
Message-Id: <20210830123433.45727-1-zhangyuwei.9149@bytedance.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 17:34:05 -04:00
Alyssa Ross
edb40732bf vhost-user: add missing space in error message
This would previously give error messages like

> Received unexpected msg type.Expected 0 received 1

Signed-off-by: Alyssa Ross <hi@alyssa.is>
Message-Id: <20210806143926.315725-1-hi@alyssa.is>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 09:07:46 -04:00
Denis Plotnikov
699f2e535d vhost: make SET_VRING_ADDR, SET_FEATURES send replies
On vhost-user-blk migration, qemu normally sends a number of commands
to enable logging if VHOST_USER_PROTOCOL_F_LOG_SHMFD is negotiated.
Qemu sends VHOST_USER_SET_FEATURES to enable buffers logging and
VHOST_USER_SET_VRING_ADDR per each started ring to enable "used ring"
data logging.
The issue is that qemu doesn't wait for reply from the vhost daemon
for these commands which may result in races between qemu expectation
of logging starting and actual login starting in vhost daemon.

The race can appear as follows: on migration setup, qemu enables dirty page
logging by sending VHOST_USER_SET_FEATURES. The command doesn't arrive to a
vhost-user-blk daemon immediately and the daemon needs some time to turn the
logging on internally. If qemu doesn't wait for reply, after sending the
command, qemu may start migrateing memory pages to a destination. At this time,
the logging may not be actually turned on in the daemon but some guest pages,
which the daemon is about to write to, may have already been transferred
without logging to the destination. Since the logging wasn't turned on,
those pages won't be transferred again as dirty. So we may end up with
corrupted data on the destination.
The same scenario is applicable for "used ring" data logging, which is
turned on with VHOST_USER_SET_VRING_ADDR command.

To resolve this issue, this patch makes qemu wait for the command result
explicitly if VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated and logging enabled.

Signed-off-by: Denis Plotnikov <den-plotnikov@yandex-team.ru>

Message-Id: <20210809104824.78830-1-den-plotnikov@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 09:07:45 -04:00
Yajun Wu
1f89d3b91e hw/virtio: Fix leak of host-notifier memory-region
If call virtio_queue_set_host_notifier_mr fails, should free
host-notifier memory-region.

Fixes: 44866521bd ("vhost-user: support registering external host notifiers")
Signed-off-by: Yajun Wu <yajunw@nvidia.com>
Message-Id: <1629077555-19907-1-git-send-email-yajunw@nvidia.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-04 09:07:45 -04:00
Markus Armbruster
998647dc8f vhost: Clean up how VhostOpts method vhost_backend_init() fails
vhost_user_backend_init() can fail without setting an error.  Unclean.
Its caller vhost_dev_init() compensates by substituting a generic
error then.  Goes back to commit 28770ff935 "vhost: Distinguish errors
in vhost_backend_init()".

Clean up by moving the generic error from vhost_dev_init() to all the
failure paths that neglect to set an error.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210720125408.387910-14-armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2021-08-26 17:15:28 +02:00
Markus Armbruster
66647ed459 vhost: Clean up how VhostOpts method vhost_get_config() fails
vhost_user_get_config() can fail without setting an error.  Unclean.
Its caller vhost_dev_get_config() compensates by substituting a
generic error then.  Goes back to commit 50de51387f "vhost:
Distinguish errors in vhost_dev_get_config()".

Clean up by moving the generic error from vhost_dev_get_config() to
all the failure paths that neglect to set an error.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210720125408.387910-13-armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Sign of error_setg_errno()'s second argument fixed in both calls]
2021-08-26 17:15:28 +02:00
Marc-André Lureau
bf7b1eab25 chardev: mark explicitly first argument as poisoned
Since commit 9894dc0cdc "char: convert
from GIOChannel to QIOChannel", the first argument to the watch callback
can actually be a QIOChannel, which is not a GIOChannel (but a QEMU
Object).

Even though we never used that pointer, change the callback type to warn
the users. Possibly a better fix later, we may want to store the
callback and call it from intermediary functions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2021-08-05 16:15:33 +04:00
Kevin Wolf
84affad1fd vhost-user: Fix backends without multiqueue support
dev->max_queues was never initialised for backends that don't support
VHOST_USER_PROTOCOL_F_MQ, so it would use 0 as the maximum number of
queues to check against and consequently fail for any such backend.

Set it to 1 if the backend doesn't have multiqueue support.

Fixes: c90bd505a3
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210705171429.29286-1-kwolf@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09 12:26:05 +02:00
Kevin Wolf
50de51387f vhost: Distinguish errors in vhost_dev_get_config()
Instead of just returning 0/-1 and letting the caller make up a
meaningless error message, add an Error parameter to allow reporting the
real error and switch to 0/-errno so that different kind of errors can
be distinguished in the caller.

config_len in vhost_user_get_config() is defined by the device, so if
it's larger than VHOST_USER_MAX_CONFIG_SIZE, this is a programming
error. Turn the corresponding check into an assertion.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210609154658.350308-6-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 13:18:42 +02:00
Kevin Wolf
f2a6e6c4fa vhost: Return 0/-errno in vhost_dev_init()
Instead of just returning 0/-1 and letting the caller make up a
meaningless error message, switch to 0/-errno so that different kinds of
errors can be distinguished in the caller.

This involves changing a few more callbacks in VhostOps to return
0/-errno: .vhost_set_owner(), .vhost_get_features() and
.vhost_virtqueue_set_busyloop_timeout(). The implementations of these
functions are trivial as they generally just send a message to the
backend.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210609154658.350308-4-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 13:16:05 +02:00
Kevin Wolf
28770ff935 vhost: Distinguish errors in vhost_backend_init()
Instead of just returning 0/-1 and letting the caller make up a
meaningless error message, add an Error parameter to allow reporting the
real error and switch to 0/-errno so that different kind of errors can
be distinguished in the caller.

Specifically, in vhost-user, EPROTO is used for all errors that relate
to the connection itself, whereas other error codes are used for errors
relating to the content of the connection. This will allow us later to
automatically reconnect when the connection goes away, without ending up
in an endless loop if it's a permanent error in the configuration.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210609154658.350308-3-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 13:16:03 +02:00
Kevin Wolf
c90bd505a3 vhost-user-blk: Check that num-queues is supported by backend
Creating a device with a number of queues that isn't supported by the
backend is pointless, the device won't work properly and the error
messages are rather confusing.

Just fail to create the device if num-queues is higher than what the
backend supports.

Since the relationship between num-queues and the number of virtqueues
depends on the specific device, this is an additional value that needs
to be initialised by the device. For convenience, allow leaving it 0 if
the check should be skipped. This makes sense for vhost-user-net where
separate vhost devices are used for the queues and custom initialisation
code is needed to perform the check.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1935031
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20210429171316.162022-7-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-05-18 12:57:39 +02:00
Greg Kurz
db8a3772e3 vhost-user: Monitor slave channel in vhost_user_read()
Now that everything is in place, have the nested event loop to monitor
the slave channel. The source in the main event loop is destroyed and
recreated to ensure any pending even for the slave channel that was
previously detected is purged. This guarantees that the main loop
wont invoke slave_read() based on an event that was already handled
by the nested loop.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210312092212.782255-7-groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-22 10:17:53 -04:00
Greg Kurz
a7f523c7d1 vhost-user: Introduce nested event loop in vhost_user_read()
A deadlock condition potentially exists if a vhost-user process needs
to request something to QEMU on the slave channel while processing a
vhost-user message.

This doesn't seem to affect any vhost-user implementation so far, but
this is currently biting the upcoming enablement of DAX with virtio-fs.
The issue is being observed when the guest does an emergency reboot while
a mapping still exits in the DAX window, which is very easy to get with
a busy enough workload (e.g. as simulated by blogbench [1]) :

- QEMU sends VHOST_USER_GET_VRING_BASE to virtiofsd.

- In order to complete the request, virtiofsd then asks QEMU to remove
  the mapping on the slave channel.

All these dialogs are synchronous, hence the deadlock.

As pointed out by Stefan Hajnoczi:

When QEMU's vhost-user master implementation sends a vhost-user protocol
message, vhost_user_read() does a "blocking" read during which slave_fd
is not monitored by QEMU.

The natural solution for this issue is an event loop. The main event
loop cannot be nested though since we have no guarantees that its
fd handlers are prepared for re-entrancy.

Introduce a new event loop that only monitors the chardev I/O for now
in vhost_user_read() and push the actual reading to a one-shot handler.
A subsequent patch will teach the loop to monitor and process messages
from the slave channel as well.

[1] https://github.com/jedisct1/Blogbench

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210312092212.782255-6-groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-22 10:17:53 -04:00
Greg Kurz
57dc02173c vhost-user: Convert slave channel to QIOChannelSocket
The slave channel is implemented with socketpair() : QEMU creates
the pair, passes one of the socket to virtiofsd and monitors the
other one with the main event loop using qemu_set_fd_handler().

In order to fix a potential deadlock between QEMU and a vhost-user
external process (e.g. virtiofsd with DAX), we want to be able to
monitor and service the slave channel while handling vhost-user
requests.

Prepare ground for this by converting the slave channel to be a
QIOChannelSocket. This will make monitoring of the slave channel
as simple as calling qio_channel_add_watch_source(). Since the
connection is already established between the two sockets, only
incoming I/O (G_IO_IN) and disconnect (G_IO_HUP) need to be
serviced.

This also allows to get rid of the ancillary data parsing since
QIOChannelSocket can do this for us. Note that the MSG_CTRUNC
check is dropped on the way because QIOChannelSocket ignores this
case. This isn't a problem since slave_read() provisions space for
8 file descriptors, but affected vhost-user slave protocol messages
generally only convey one. If for some reason a buggy implementation
passes more file descriptors, no need to break the connection, just
like we don't break it if some other type of ancillary data is
received : this isn't explicitely violating the protocol per-se so
it seems better to ignore it.

The current code errors out on short reads and writes. Use the
qio_channel_*_all() variants to address this on the way.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210312092212.782255-5-groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-22 10:17:53 -04:00
Greg Kurz
de62e49460 vhost-user: Factor out duplicated slave_fd teardown code
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210312092212.782255-4-groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-22 10:17:53 -04:00
Greg Kurz
9e06080bed vhost-user: Fix double-close on slave_read() error path
Some message types, e.g. VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
can convey file descriptors. These must be closed before returning
from slave_read() to avoid being leaked. This can currently be done
in two different places:

[1] just after the request has been processed

[2] on the error path, under the goto label err:

These path are supposed to be mutually exclusive but they are not
actually. If the VHOST_USER_NEED_REPLY_MASK flag was passed and the
sending of the reply fails, both [1] and [2] are performed with the
same descriptor values. This can potentially cause subtle bugs if one
of the descriptor was recycled by some other thread in the meantime.

This code duplication complicates rollback for no real good benefit.
Do the closing in a unique place, under a new fdcleanup: goto label
at the end of the function.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210312092212.782255-3-groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-22 10:17:53 -04:00
Greg Kurz
a890557d5a vhost-user: Drop misleading EAGAIN checks in slave_read()
slave_read() checks EAGAIN when reading or writing to the socket
fails. This gives the impression that the slave channel is in
non-blocking mode, which is certainly not the case with the current
code base. And the rest of the code isn't actually ready to cope
with non-blocking I/O.

Just drop the checks everywhere in this function for the sake of
clarity.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20210312092212.782255-2-groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-03-22 10:17:53 -04:00
Stefan Hajnoczi
3009edff81 vhost-user: fix VHOST_USER_ADD/REM_MEM_REG truncation
QEMU currently truncates the mmap_offset field when sending
VHOST_USER_ADD_MEM_REG and VHOST_USER_REM_MEM_REG messages. The struct
layout looks like this:

  typedef struct VhostUserMemoryRegion {
      uint64_t guest_phys_addr;
      uint64_t memory_size;
      uint64_t userspace_addr;
      uint64_t mmap_offset;
  } VhostUserMemoryRegion;

  typedef struct VhostUserMemRegMsg {
      uint32_t padding;
      /* WARNING: there is a 32-bit hole here! */
      VhostUserMemoryRegion region;
  } VhostUserMemRegMsg;

The payload size is calculated as follows when sending the message in
hw/virtio/vhost-user.c:

  msg->hdr.size = sizeof(msg->payload.mem_reg.padding) +
      sizeof(VhostUserMemoryRegion);

This calculation produces an incorrect result of only 36 bytes.
sizeof(VhostUserMemRegMsg) is actually 40 bytes.

The consequence of this is that the final field, mmap_offset, is
truncated. This breaks x86_64 TCG guests on s390 hosts. Other guest/host
combinations may get lucky if either of the following holds:
1. The guest memory layout does not need mmap_offset != 0.
2. The host is little-endian and mmap_offset <= 0xffffffff so the
   truncation has no effect.

Fix this by extending the existing 32-bit padding field to 64-bit. Now
the padding reflects the actual compiler padding. This can be verified
using pahole(1).

Also document the layout properly in the vhost-user specification.  The
vhost-user spec did not document the exact layout. It would be
impossible to implement the spec without looking at the QEMU source
code.

Existing vhost-user frontends and device backends continue to work after
this fix has been applied. The only change in the wire protocol is that
QEMU now sets hdr.size to 40 instead of 36. If a vhost-user
implementation has a hardcoded size check for 36 bytes, then it will
fail with new QEMUs. Both QEMU and DPDK/SPDK don't check the exact
payload size, so they continue to work.

Fixes: f1aeb14b08 ("Transmit vhost-user memory regions individually")
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201109174355.1069147-1-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fixes: f1aeb14b08 ("Transmit vhost-user memory regions individually")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
2020-11-12 09:19:40 -05:00
Chen Qun
8b616beebc hw/virtio/vhost-user:Remove dead assignment in scrub_shadow_regions()
Clang static code analyzer show warning:
hw/virtio/vhost-user.c:606:9: warning: Value stored to 'mr' is never read
        mr = vhost_user_get_mr_data(reg->userspace_addr, &offset, &fd);
        ^    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20200827110311.164316-6-kuhn.chenqun@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-09-01 11:58:32 +02:00
Raphael Norwitz
4fdecf0543 Fix vhost-user buffer over-read on ram hot-unplug
The VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS vhost-user protocol
feature introduced a shadow-table, used by the backend to dynamically
determine how a vdev's memory regions have changed since the last
vhost_user_set_mem_table() call. On hot-remove, a memmove() operation
is used to overwrite the removed shadow region descriptor(s). The size
parameter of this memmove was off by 1 such that if a VM with a backend
supporting the VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS filled it's
shadow-table (by performing the maximum number of supported hot-add
operatons) and attempted to remove the last region, Qemu would read an
out of bounds value and potentially crash.

This change fixes the memmove() bounds such that this erroneous read can
never happen.

Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1594799958-31356-1-git-send-email-raphael.norwitz@nutanix.com>
Fixes: f1aeb14b08 ("Transmit vhost-user memory regions individually")
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-07-27 10:28:28 -04:00
Raphael Norwitz
8d19371593 Stop vhost-user sending uninitialized mmap_offsets
Prior to this change, the vhost_user_fill_msg_region function filled out
all elements of the VhostUserMemoryRegion struct except the mmap_offset.

This function is often called on uninitialized structs, which are then
copied into VHOST_USER_SET_MEM_TABLE and VHOST_USER_ADD/REM_MEM_REG
messages. In some cases, where the mmap_offset was not needed, it was
left uninitialized, causing QEMU to send the backend uninitialized data,
which Coverity flagged as a series of issues.

This change augments the vhost_user_fill_msg_region API, adding a
mmap_offset paramenter, forcing the caller to initialize mmap_offset.

Fixes: ece99091c2
Fixes: f1aeb14b08
Reported-by: Coverity (CIDs 1429802, 1429803 and 1429804)
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1592650156-25845-1-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-06-24 17:18:28 -04:00
Raphael Norwitz
27598393a2 Lift max memory slots limit imposed by vhost-user
Historically, sending all memory regions to vhost-user backends in a
single message imposed a limitation on the number of times memory
could be hot-added to a VM with a vhost-user device. Now that backends
which support the VHOST_USER_PROTOCOL_F_CONFIGURE_SLOTS send memory
regions individually, we no longer need to impose this limitation on
devices which support this feature.

With this change, VMs with a vhost-user device which supports the
VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS can support a configurable
number of memory slots, up to the maximum allowed by the target
platform.

Existing backends which do not support
VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS are unaffected.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Suggested-by: Mike Cui <cui@nutanix.com>
Message-Id: <1588533678-23450-6-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-06-12 10:17:06 -04:00
Raphael Norwitz
f1aeb14b08 Transmit vhost-user memory regions individually
With this change, when the VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS
protocol feature has been negotiated, Qemu no longer sends the backend
all the memory regions in a single message. Rather, when the memory
tables are set or updated, a series of VHOST_USER_ADD_MEM_REG and
VHOST_USER_REM_MEM_REG messages are sent to transmit the regions to map
and/or unmap instead of sending send all the regions in one fixed size
VHOST_USER_SET_MEM_TABLE message.

The vhost_user struct maintains a shadow state of the VM’s memory
regions. When the memory tables are modified, the
vhost_user_set_mem_table() function compares the new device memory state
to the shadow state and only sends regions which need to be unmapped or
mapped in. The regions which must be unmapped are sent first, followed
by the new regions to be mapped in. After all the messages have been
sent, the shadow state is set to the current virtual device state.

Existing backends which do not support
VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS are unaffected.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Swapnil Ingle <swapnil.ingle@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Suggested-by: Mike Cui <cui@nutanix.com>
Message-Id: <1588533678-23450-5-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-06-12 10:17:06 -04:00
Raphael Norwitz
6b0eff1a4e Add VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS
This change introduces a new feature to the vhost-user protocol allowing
a backend device to specify the maximum number of ram slots it supports.

At this point, the value returned by the backend will be capped at the
maximum number of ram slots which can be supported by vhost-user, which
is currently set to 8 because of underlying protocol limitations.

The returned value will be stored inside the VhostUserState struct so
that on device reconnect we can verify that the ram slot limitation
has not decreased since the last time the device connected.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Message-Id: <1588533678-23450-4-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-06-12 10:17:06 -04:00
Raphael Norwitz
23374a84c5 Add vhost-user helper to get MemoryRegion data
When setting the memory tables, qemu uses a memory region's userspace
address to look up the region's MemoryRegion struct. Among other things,
the MemoryRegion contains the region's offset and associated file
descriptor, all of which need to be sent to the backend.

With VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS, this logic will be
needed in multiple places, so before feature support is added it
should be moved to a helper function.

This helper is also used to simplify the vhost_user_can_merge()
function.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1588533678-23450-3-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-06-09 14:18:04 -04:00
Raphael Norwitz
ece99091c2 Add helper to populate vhost-user message regions
When setting vhost-user memory tables, memory region descriptors must be
copied from the vhost_dev struct to the vhost-user message. To avoid
duplicating code in setting the memory tables, we should use a helper to
populate this field. This change adds this helper.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1588533678-23450-2-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2020-06-09 14:18:04 -04:00
Raphael Norwitz
2d9da9dff3 Refactor vhost_user_set_mem_table functions
vhost_user_set_mem_table() and vhost_user_set_mem_table_postcopy() have
gotten convoluted, and have some identical code.

This change moves the logic populating the VhostUserMemory struct and
fds array from vhost_user_set_mem_table() and
vhost_user_set_mem_table_postcopy() to a new function,
vhost_user_fill_set_mem_table_msg().

No functionality is impacted.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Message-Id: <1585132506-13316-1-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-05-04 10:25:03 -04:00
Raphael Norwitz
b844a4c77b Fixed assert in vhost_user_set_mem_table_postcopy
The current vhost_user_set_mem_table_postcopy() implementation
populates each region of the VHOST_USER_SET_MEM_TABLE message without
first checking if there are more than VHOST_MEMORY_MAX_NREGIONS already
populated. This can cause memory corruption if too many regions are
added to the message during the postcopy step.

This change moves an existing assert up such that attempting to
construct a VHOST_USER_SET_MEM_TABLE message with too many memory
regions will gracefully bring down qemu instead of corrupting memory.

Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Message-Id: <1579143426-18305-2-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-27 03:46:10 -05:00
Adrian Moreno
67b3965e89 vhost-user: only set slave channel for first vq
When multiqueue is enabled, a vhost_dev is created for each queue
pair. However, only one slave channel is needed.

Fixes: 4bbeeba023 (vhost-user: add slave-req-fd support)
Cc: marcandre.lureau@redhat.com
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Message-Id: <20200121214553.28459-1-amorenoz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-27 03:46:10 -05:00
Dr. David Alan Gilbert
0fdc465d7d vhost-user: Print unexpected slave message types
When we receive an unexpected message type on the slave fd, print
the type.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-23 16:41:37 +00:00
Raphael Norwitz
d91d57e604 vhost-user: add VHOST_USER_RESET_DEVICE to reset devices
Add a VHOST_USER_RESET_DEVICE message which will reset the vhost user
backend. Disabling all rings, and resetting all internal state, ready
for the backend to be reinitialized.

A backend has to report it supports this features with the
VHOST_USER_PROTOCOL_F_RESET_DEVICE protocol feature bit. If it does
so, the new message is used instead of sending a RESET_OWNER which has
had inconsistent implementations.

Signed-off-by: David Vrabel <david.vrabel@nutanix.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1572385083-5254-2-git-send-email-raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-01-05 07:03:03 -05:00
Markus Armbruster
db72581598 Include qemu/main-loop.h less
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).  It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.

Include qemu/main-loop.h only where it's needed.  Touching it now
recompiles only some 1700 objects.  For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800.  For the
others, they shrink only slightly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Marc-André Lureau
bd2e44fee4 vhost-user: add vhost_user_gpu_set_socket()
Add a new vhost-user message to give a unix socket to a vhost-user
backend for GPU display updates.

Back when I started that work, I added a new GPU channel because the
vhost-user protocol wasn't bidirectional. Since then, there is a
vhost-user-slave channel for the slave to send requests to the master.
We could extend it with GPU messages. However, the GPU protocol is
quite orthogonal to vhost-user, thus I chose to have a new dedicated
channel.

See vhost-user-gpu.rst for the protocol details.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20190524130946.31736-2-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2019-05-29 06:29:07 +02:00
Xie Yongji
5ad204bf2a vhost-user: Support transferring inflight buffer between qemu and backend
This patch introduces two new messages VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD to support transferring a shared
buffer between qemu and backend.

Firstly, qemu uses VHOST_USER_GET_INFLIGHT_FD to get the
shared buffer from backend. Then qemu should send it back
through VHOST_USER_SET_INFLIGHT_FD each time we start vhost-user.

This shared buffer is used to track inflight I/O by backend.
Qemu should retrieve a new one when vm reset.

Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Chai Wen <chaiwen@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Message-Id: <20190228085355.9614-2-xieyongji@baidu.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-12 22:31:21 -04:00
Marc-André Lureau
9af84c02e2 vhost-user: split vhost_user_read()
Split vhost_user_read(), so only header can be read with
vhost_user_read_header().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190308140454.32437-8-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-12 22:31:21 -04:00
Marc-André Lureau
917d7dd72a vhost-user: wrap some read/write with retry handling
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20190308140454.32437-6-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-12 21:22:31 -04:00
Marc-André Lureau
0b99f22461 vhost-user: simplify vhost_user_init/vhost_user_cleanup
Take a VhostUserState* that can be pre-allocated, and initialize it
with the associated chardev.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>
Message-Id: <20190308140454.32437-4-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-12 21:22:31 -04:00
Paolo Bonzini
18658a3ced vhost: restrict Linux dependency to kernel vhost
vhost-user does not depend on Linux; it can run on any POSIX system.  Restrict
vhost-kernel to Linux in hw/virtio/vhost-backend.c, everything else can be
compiled on all POSIX systems.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1543851204-41186-4-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1550165756-21617-4-git-send-email-pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-02-21 12:28:01 -05:00
Li Qiang
b0aa77d36d vhost-user: fix ioeventfd_enabled
Currently, the vhost-user-test assumes the eventfd is available.
However it's not true because the accel is qtest. So the
'vhost_set_vring_file' will not add fds to the msg and the server
side of vhost-user-test will be broken. The bug is in 'ioeventfd_enabled'.
We should make this function return true if not using kvm accel.

Signed-off-by: Li Qiang <liq3ea@163.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-01-14 19:31:04 -05:00
Ilya Maximets
5ce43896e1 vhost-user: Don't ask for reply on postcopy mem table set
According to documentation, NEED_REPLY_MASK should not be set
for VHOST_USER_SET_MEM_TABLE request in postcopy mode.
This restriction was mistakenly applied to 'reply_supported'
variable, which is local and used only for non-postcopy case.

CC: Dr. David Alan Gilbert <dgilbert@redhat.com>
Fixes: 9bb3801994 ("vhost+postcopy: Send address back to qemu")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Message-Id: <20181002140947.4107-1-i.maximets@samsung.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-10-11 19:58:26 +01:00
Ilya Maximets
c4f753859a vhost-user: Fix userfaultfd leak
'fd' received from the vhost side is never freed.
Also, everything (including 'postcopy_listen' state) should be
cleaned up on vhost cleanup.

Fixes: 46343570c0 ("vhost+postcopy: Wire up POSTCOPY_END notify")
Fixes: f82c11165f ("vhost+postcopy: Register shared ufd with postcopy")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Message-Id: <20181008160536.6332-3-i.maximets@samsung.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-10-11 19:58:26 +01:00
Tiwei Bie
44866521bd vhost-user: support registering external host notifiers
This patch introduces VHOST_USER_PROTOCOL_F_HOST_NOTIFIER.
With this feature negotiated, vhost-user backend can register
memory region based host notifiers. And it will allow the guest
driver in the VM to notify the hardware accelerator at the
vhost-user backend directly.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-24 21:14:11 +03:00
Tiwei Bie
4d0cf552d3 vhost-user: introduce shared vhost-user state
When multi queue is enabled e.g. for a virtio-net device,
each queue pair will have a vhost_dev, and the only thing
shared between vhost devs currently is the chardev. This
patch introduces a vhost-user state structure which will
be shared by all vhost devs of the same virtio device.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-24 21:14:11 +03:00
Tiwei Bie
5f57fbeaaf vhost-user: allow slave to send fds via slave channel
Introduce VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD protocol
feature to allow slave to send at most 8 descriptors
in each message to master via ancillary data using the
slave channel.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-24 21:14:10 +03:00
Tiwei Bie
988a27754b vhost: allow backends to filter memory sections
This patch introduces a vhost op for vhost backends to allow
them to filter the memory sections that they can handle.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-24 21:14:10 +03:00
Richard Henderson
ebf2a499a5 hw/virtio: Fix brace Werror with clang 6.0.0
The warning is

hw/virtio/vhost-user.c:1319:26: error: suggest braces
      around initialization of subobject [-Werror,-Wmissing-braces]
    VhostUserMsg msg = { 0 };
                         ^
                         {}

While the original code is correct, and technically exactly correct
as per ISO C89, both GCC and Clang support plain empty set of braces
as an extension.

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-23 17:02:02 +03:00
Dr. David Alan Gilbert
9952e807fd vhost-user+postcopy: Use qemu_set_nonblock
Use qemu_set_nonblock rather than a simple fcntl; cleaner
and I have no reason to change other flags.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-23 17:02:02 +03:00
Tiwei Bie
1f3a4519b1 vhost-user: support receiving file descriptors in slave_read
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-05-23 17:01:54 +03:00
Maxime Coquelin
1c3e5a2617 vhost-user: back SET/GET_CONFIG requests with a protocol feature
Without a dedicated protocol feature, QEMU cannot know whether
the backend can handle VHOST_USER_SET_CONFIG and
VHOST_USER_GET_CONFIG messages.

This patch adds a protocol feature that is only advertised by
QEMU if the device implements the config ops. Vhost user init
fails if the device support the feature but the backend doesn't.

The backend should only send VHOST_USER_SLAVE_CONFIG_CHANGE_MSG
requests if the protocol feature has been negotiated.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Changpeng Liu <changpeng.liu@intel.com>
2018-04-09 17:35:46 +03:00
Dr. David Alan Gilbert
46343570c0 vhost+postcopy: Wire up POSTCOPY_END notify
Wire up a call to VHOST_USER_POSTCOPY_END message to the vhost clients
right before we ask the listener thread to shutdown.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 16:40:37 +02:00
Dr. David Alan Gilbert
c639187e33 vhost-user: Add VHOST_USER_POSTCOPY_END message
This message is sent just before the end of postcopy to get the
client to stop using userfault since we wont respond to any more
requests.  It should close userfaultfd so that any other pages
get mapped to the backing file automatically by the kernel, since
at this point we know we've received everything.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 16:40:37 +02:00
Dr. David Alan Gilbert
c07e36158f vhost+postcopy: Add vhost waker
Register a waker function in vhost-user code to be notified when
pages arrive or requests to previously mapped pages get requested.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 16:40:37 +02:00
Dr. David Alan Gilbert
375318d03f vhost+postcopy: Resolve client address
Resolve fault addresses read off the clients UFD into RAMBlock
and offset, and call back to the postcopy code to ask for the page.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 16:40:19 +02:00
Dr. David Alan Gilbert
905125d0e2 vhost+postcopy: Stash RAMBlock and offset
Stash the RAMBlock and offset for later use looking up
addresses.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:28 +02:00
Dr. David Alan Gilbert
9bb3801994 vhost+postcopy: Send address back to qemu
We need a better way, but at the moment we need the address of the
mappings sent back to qemu so it can interpret the messages on the
userfaultfd it reads.

This is done as a 3 stage set:
   QEMU -> client
      set_mem_table

   mmap stuff, get addresses

   client -> qemu
       here are the addresses

   qemu -> client
       OK - now you can use them

That ensures that qemu has registered the new addresses in it's
userfault code before the client starts accessing them.

Note: We don't ask for the default 'ack' reply since we've got our own.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:28 +02:00
Dr. David Alan Gilbert
55d754b307 postcopy+vhost-user: Split set_mem_table for postcopy
Split the set_mem_table routines in both qemu and libvhost-user
because the postcopy versions are going to be quite different
once changes in the later patches are added. However, this patch
doesn't produce any functional change, just the split.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:28 +02:00
Dr. David Alan Gilbert
6864a7b5ac vhost+postcopy: Transmit 'listen' to slave
Notify the vhost-user slave on reception of the 'postcopy-listen'
event from the source.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:28 +02:00
Dr. David Alan Gilbert
f82c11165f vhost+postcopy: Register shared ufd with postcopy
Register the UFD that comes in as the response to the 'advise' method
with the postcopy code.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:28 +02:00
Dr. David Alan Gilbert
d3dff7a5a1 vhost-user: Add 'VHOST_USER_POSTCOPY_ADVISE' message
Wire up a notifier to send a VHOST_USER_POSTCOPY_ADVISE
message on an incoming advise.

Later patches will fill in the behaviour/contents of the
message.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:27 +02:00
Dr. David Alan Gilbert
9ccbfe14dd postcopy: Add vhost-user flag for postcopy and check it
Add a vhost feature flag for postcopy support, and
use the postcopy notifier to check it before allowing postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 05:03:27 +02:00
Gonglei
efbfeb8180 cryptodev-vhost-user: add crypto session handler
Introduce two vhost-user meassges: VHOST_USER_CREATE_CRYPTO_SESSION
and VHOST_USER_CLOSE_CRYPTO_SESSION. At this point, the QEMU side
support crypto operation in cryptodev host-user backend.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-01 18:26:17 +02:00
Jay Zhou
f4bf56fb78 vhost: remove assertion to prevent crash
QEMU will assert on vhost-user backed virtio device hotplug if QEMU is
using more RAM regions than VHOST_MEMORY_MAX_NREGIONS (for example if
it were started with a lot of DIMM devices).

Fix it by returning error instead of asserting and let callers of
vhost_set_mem_table() handle error condition gracefully.

Cc: qemu-stable@nongnu.org
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-18 21:52:39 +02:00
Michael S. Tsirkin
69aff03064 vhost-user: fix misaligned access to payload
We currently take a pointer to a misaligned field of a packed structure.
clang reports this as a build warning.
A fix is to keep payload in a separate structure, and access is it
from there using a vectored write.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-18 21:52:39 +02:00
Michael S. Tsirkin
24e34754eb vhost-user: factor out msg head and payload
split header and payload into separate structures,
to enable easier handling of alignment issues.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-18 21:52:39 +02:00
Changpeng Liu
4c3e257b5e vhost-user: add new vhost user messages to support virtio config space
Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be
used for live migration of vhost user devices, also vhost user devices
can benefit from the messages to get/set virtio config space from/to the
I/O target. For the purpose to support virtio config space change,
VHOST_USER_SLAVE_CONFIG_CHANGE_MSG message is added as the event notifier
in case virtio config space change in the slave I/O target.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-18 21:52:37 +02:00
Felipe Franciosi
5df04f1762 vhost-user: fix legacy cross-endian configurations
Currently, vhost-user does not implement any means for notifying the
backend about guest endianess. This commit introduces a new message
called VHOST_USER_SET_VRING_ENDIAN which is analogous to the ioctl()
called VHOST_SET_VRING_ENDIAN used for kernel vhost backends. Such
message is necessary for backends supporting legacy (pre-1.0) virtio
devices running in big-endian guests.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Mike Cui <cui@nutanix.com>
2017-08-02 00:13:25 +03:00
Maxime Coquelin
b9ec9bd468 vhost-user: unregister slave req handler at cleanup time
If the backend sends a request just before closing the socket,
the aio dispatcher might schedule its reading after the vhost
device has been cleaned, leading to a NULL pointer dereference
in slave_read();

vhost_user_cleanup() already closes the socket but it is not
enough, the handler has to be unregistered.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-07-03 22:29:49 +03:00
Peter Maydell
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Merge remote-tracking branch 'remotes/elmarco/tags/chrfe-pull-request' into staging

# gpg: Signature made Fri 02 Jun 2017 20:12:48 BST
# gpg:                using RSA key 0xDAE8E10975969CE5
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>"
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/elmarco/tags/chrfe-pull-request:
  char: move char devices to chardev/
  char: make chr_fe_deinit() optionaly delete backend
  char: rename functions that are not part of fe
  char: move CharBackend handling in char-fe unit
  char: generalize qemu_chr_write_all()
  be-hci: use backend functions
  chardev: serial & parallel declaration to own headers
  chardev: move headers to include/chardev
  Remove/replace sysemu/char.h inclusion
  char-win: close file handle except with console
  char-win: rename hcom->file
  char-win: rename win_chr_init/poll win_chr_serial_init/poll
  char-win: remove WinChardev.len
  char-win: simplify win_chr_read()
  char: cast ARRAY_SIZE() as signed to silent warning on empty array

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-05 10:09:14 +01:00
Maxime Coquelin
6dcdd06e3b spec/vhost-user spec: Add IOMMU support
This patch specifies and implements the master/slave communication
to support device IOTLB in slave.

The vhost_iotlb_msg structure introduced for kernel backends is
re-used, making the design close between the two backends.

An exception is the use of the secondary channel to enable the
slave to send IOTLB miss requests to the master.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-06-02 18:57:17 +03:00
Marc-André Lureau
4bbeeba023 vhost-user: add slave-req-fd support
Learn to give a socket to the slave to let him make requests to the
master.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-06-02 18:57:17 +03:00
Marc-André Lureau
2152f3fead vhost-user: add vhost_user to hold the chr
Next patches will add more fields to the structure

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-06-02 18:57:17 +03:00
Marc-André Lureau
4d43a603c7 char: move CharBackend handling in char-fe unit
Move all the frontend struct and methods to a seperate unit. This avoids
accidentally mixing backend and frontend calls, and helps with readabilty.

Make qemu_chr_replay() a macro shared by both char and char-fe.

Export qemu_chr_write(), and use a macro for qemu_chr_write_all()

(nb: yes, CharBackend is for char frontend :)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-06-02 11:33:53 +04:00
Marc-André Lureau
8228e353d8 chardev: move headers to include/chardev
So they are all in one place. The following patch will move serial &
parallel declarations to the respective headers.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-06-02 11:33:52 +04:00
Maxime Coquelin
3cf7daf8c3 vhost-user: pass message as a pointer to process_message_reply()
process_message_reply() was recently updated to get full message
content instead of only its request field.

There is no need to copy all the struct content into the stack,
so just pass its pointer as const.

Reviewed-by: Jens Freimann <jfreiman@redhat.com>
Reviewed-by: Zhiyong Yang <zhiyong.yang@intel.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-05-25 21:25:28 +03:00
Juan Quintela
68ba3b0743 migration: migration.h was not needed
This files don't use any function from migration.h, so drop it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
2017-05-18 19:20:59 +02:00
Zhiyong Yang
60cd11024f hw/virtio: fix vhost user fails to startup when MQ
Qemu2.7~2.9 and vhost user for dpdk 17.02 release work together
to cause failures of new connection when negotiating to set MQ.
(one queue pair works well).
   Because there exist some bugs in qemu code when introducing
VHOST_USER_PROTOCOL_F_REPLY_ACK to qemu. When vhost_user_set_mem_table
is invoked to deal with the vhost message VHOST_USER_SET_MEM_TABLE
for the second time, qemu indeed doesn't send the messge (The message
needs to be sent only once)but still will be waiting for dpdk's reply
ack, then, qemu is always freezing, while DPDK is always waiting for
next vhost message from qemu.
  The patch aims to fix the bug, MQ can work well.
  The same bug is found in function vhost_user_net_set_mtu, it is fixed
at the same time.
  DPDK related patch is as following:
  http://www.dpdk.org/dev/patchwork/patch/23955/

Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
Cc: qemu-stable@nongnu.org
Fixes: ca525ce561 ("vhost-user: Introduce a new protocol feature REPLY_ACK.")
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Jens Freimann <jfreiman@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-05-10 22:04:23 +03:00
Maxime Coquelin
c5f048d8fb vhost-user: Add MTU protocol feature and op
This patch implements VHOST_USER_PROTOCOL_F_NET_MTU
protocol feature and VHOST_USER_NET_SET_MTU request so
that the backend gets notified of the user defined host
MTU.

If backend supports VHOST_USER_PROTOCOL_F_REPLY_ACK,
QEMU assumes MTU is valid if success is returned.

Vhost-net driver sends this request through a new
vhost_net_set_mtu vhost_ops entry.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Aaron Conole <aconole@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-01-10 07:02:53 +02:00
Marc-André Lureau
5345fdb446 char: use qemu_chr_fe* functions with CharBackend argument
This also switches from qemu_chr_add_handlers() to
qemu_chr_fe_set_handlers(). Note that qemu_chr_fe_set_handlers() now
takes the focus when fe_open (qemu_chr_add_handlers() did take the
focus)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-16-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24 15:27:21 +02:00
Michael S. Tsirkin
94c9cb31c0 Revert "vhost-user: Attempt to fix a race with set_mem_table."
This reverts commit 28ed5ef163.

I still think it's the right thing to do, but
tests have been failing sporadically.

Revert for now, and hope to fix it before the release.

Cc: Prerna Saxena <prerna.saxena@nutanix.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Marc-André Lureau <mlureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 1471268075-3425-1-git-send-email-mst@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-08-15 15:12:21 +01:00
Prerna Saxena
28ed5ef163 vhost-user: Attempt to fix a race with set_mem_table.
The set_mem_table command currently does not seek a reply. Hence, there is
no easy way for a remote application to notify to QEMU when it finished
setting up memory, or if there were errors doing so.

As an example:
(1) Qemu sends a SET_MEM_TABLE to the backend (eg, a vhost-user net
application). SET_MEM_TABLE does not require a reply according to the spec.
(2) Qemu commits the memory to the guest.
(3) Guest issues an I/O operation over a new memory region which was configured on (1).
(4) The application has not yet remapped the memory, but it sees the I/O request.
(5) The application cannot satisfy the request because it does not know about those GPAs.

While a guaranteed fix would require a protocol extension (committed separately),
a best-effort workaround for existing applications is to send a GET_FEATURES
message before completing the vhost_user_set_mem_table() call.
Since GET_FEATURES requires a reply, an application that processes vhost-user
messages synchronously would probably have completed the SET_MEM_TABLE before replying.

Signed-off-by: Prerna Saxena <prerna.saxena@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-10 17:47:29 +03:00
Prerna Saxena
ca525ce561 vhost-user: Introduce a new protocol feature REPLY_ACK.
This introduces the VHOST_USER_PROTOCOL_F_REPLY_ACK.

If negotiated, client applications should send a u64 payload in
response to any message that contains the "need_reply" bit set
on the message flags. Setting the payload to "zero" indicates the
command finished successfully. Likewise, setting it to "non-zero"
indicates an error.

Currently implemented only for SET_MEM_TABLE.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Prerna Saxena <prerna.saxena@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-10 17:47:29 +03:00
Marc-André Lureau
f6b8571041 vhost-user: add error report in vhost_user_write()
Similar to vhost_user_read() error report, it is useful to have early
error report.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:49 +03:00
Marc-André Lureau
c4843a45e3 vhost-user: check vhost_user_{read,write}() return value
The vhost-user code is quite inconsistent with error handling. Instead
of ignoring some return values of read/write and silently going on with
invalid state (invalid read for example), break the code flow when the
error happened.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:48 +03:00
Marc-André Lureau
6fab2f3f60 vhost-user: check qemu_chr_fe_set_msgfds() return value
Check qemu_chr_fe_set_msgfds() for errors, to make sure the message to
be sent is correct.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:48 +03:00
Marc-André Lureau
df3485a148 vhost-user: call set_msgfds unconditionally
It is fine to call set_msgfds() with 0 fd, and ensures any previous fd
array is cleared.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-29 00:33:47 +03:00
Paolo Bonzini
07bdaa4196 memory: split memory_region_from_host from qemu_ram_addr_from_host
Move the old qemu_ram_addr_from_host to memory_region_from_host and
make it return an offset within the region.  For qemu_ram_addr_from_host
return the ram_addr_t directly, similar to what it was before
commit 1b5ec23 ("memory: return MemoryRegion from qemu_ram_addr_from_host",
2013-07-04).

Reviewed-by: Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-29 09:11:12 +02:00
Paolo Bonzini
4ff87573df memory: remove qemu_get_ram_fd, qemu_set_ram_fd, qemu_ram_block_host_ptr
Remove direct uses of ram_addr_t and optimize memory_region_{get,set}_fd
now that a MemoryRegion knows its RAMBlock directly.

Reviewed-by: Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-29 09:11:12 +02:00
Markus Armbruster
da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Michael S. Tsirkin
ffe42cc14c vhost-user: don't merge regions with different fds
vhost currently merges regions with contiguious virtual and physical
addresses.  This breaks for vhost-user since that also needs fds to
match.

Add a vhost_ops entry to compare the fds for vhost-user only.

Cc: qemu-stable@nongnu.org
Cc: Victor Kaplansky <victork@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-02-23 12:55:16 +02:00
Peter Maydell
9b8bfe21be virtio: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-15-git-send-email-peter.maydell@linaro.org
2016-01-29 15:07:23 +00:00