Commit Graph

89 Commits

Author SHA1 Message Date
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
Michael S. Tsirkin 48854f57ce vhost-user: fix log size
commit 2b8819c6ee
("vhost-user: modify SET_LOG_BASE to pass mmap size and offset")
passes log size in units of 4 byte chunks instead of the
expected size in bytes.

Fix this up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-18 18:49:27 +02:00
Michael S. Tsirkin dc3db6adde vhost-user: start/stop all rings
We are currently only sending VRING_ENABLE message for the first ring,
that's wrong: we must start/stop them all.

Reported-by: Victor Kaplansky <victork@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-16 18:48:31 +02:00
Michael S. Tsirkin 5421f318ec vhost-user: print original request on error
When we get an unexpected response, print out
the original request.
Helps debug protocol errors tremendously.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-16 14:35:16 +02:00
Yuanhan Liu 923e2d98ed vhost: let SET_VRING_ENABLE message depends on protocol feature
But not depend on PROTOCOL_F_MQ feature bit. So that we could use
SET_VRING_ENABLE to sign the backend on stop, even if MQ is disabled.

That's reasonable, since we will have one queue pair at least.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-16 12:02:54 +02:00
Yuanhan Liu 60915dc469 vhost: rename RESET_DEVICE backto RESET_OWNER
This patch basically reverts commit d1f8b30e.

It turned out that it breaks stuff, so revert it:
    http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html

CC: "Michael S. Tsirkin" <mst@redhat.com>
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-12 15:49:33 +02:00
Victor Kaplansky 2b8819c6ee vhost-user: modify SET_LOG_BASE to pass mmap size and offset
Unlike the kernel, vhost-user application accesses log table by
mmaping it to its user space. This change adds two new fields to
VhostUserMsg payload: mmap_size, and mmap_offset and make QEMU to
pass the to vhost-user application in VHOST_USER_SET_LOG_BASE
request.

Signed-off-by: Victor Kaplansky <victork@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-12 15:49:33 +02:00
Michael S. Tsirkin 7fc0246c07 vhost-user: cleanup msg size math
We are sending msg fields, use sizeof on these
and not on local variables which happen to
have a matching type.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-29 11:05:24 +02:00
Michael S. Tsirkin 86abad0fed vhost-user: cleanup struct size math
We are using local msg structures everywhere, use them
for sizeof as well.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-29 11:05:24 +02:00
Michael S. Tsirkin 7f4a930e64 vhost-user: fix up rhel6 build
Build on RHEL6 fails:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42875

Apparently unnamed unions couldn't use C99  named field initializers.
Let's just name the payload union field.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-22 22:34:59 +03:00
Thibaut Collet de1372d466 vhost-user: use an enum helper for features mask
The VHOST_USER_PROTOCOL_FEATURE_MASK will be automatically updated when
adding new features to the enum.

Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
[Adapted from mailing list discussion - Marc-André]
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>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Thibaut Collet 3e866365e1 vhost user: add rarp sending after live migration for legacy guest
A new vhost user message is added to allow QEMU to ask to vhost user backend to
broadcast a fake RARP after live migration for guest without GUEST_ANNOUNCE
capability.

This new message is sent only if the backend supports the new
VHOST_USER_PROTOCOL_F_RARP protocol feature.
The payload of this new message is the MAC address of the guest (not known by
the backend). The MAC address is copied in the first 6 bytes of a u64 to avoid
to create a new payload message type.

This new message has no equivalent ioctl so a new callback is added in the
userOps structure to send the request.

Upon reception of this new message the vhost user backend must generate and
broadcast a fake RARP request to notify the migration is terminated.

Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
[Rebased and fixed checkpatch errors - Marc-André]
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>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Marc-André Lureau 21e704256d vhost: use a function for each call
Replace the generic vhost_call() by specific functions for each
function call to help with type safety and changing arguments.

While doing this, I found that "unsigned long long" and "uint64_t" were
used interchangeably and causing compilation warnings, using uint64_t
instead, as the vhost & protocol specifies.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[Fix enum usage and MQ - Thibaut Collet]
Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Marc-André Lureau d2fc4402cb vhost-user: add a migration blocker
If VHOST_USER_PROTOCOL_F_LOG_SHMFD is not announced, block vhost-user
migration. The blocker is removed in vhost_dev_cleanup().

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>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Marc-André Lureau 9a78a5dd27 vhost-user: send log shm fd along with log_base
Send the shm for the dirty pages logging if the backend supports
VHOST_USER_PROTOCOL_F_LOG_SHMFD. Wait for a reply to make sure
the old log is no longer used.

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>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Marc-André Lureau 1be0ac2109 vhost-user: add vhost_user_requires_shm_log()
Check if the backend has VHOST_USER_PROTOCOL_F_LOG_SHMFD feature and
require a shared log.

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>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Marc-André Lureau c2bea314f6 vhost: add vhost_set_log_base op
Split VHOST_SET_LOG_BASE call in a seperate function callback, so that
type safety works and more arguments can be added in the next patches.

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>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:49 +03:00
Igor Mammedov 2ce68e4cf5 vhost: add vhost_has_free_slot() interface
it will allow for other parts of QEMU check if it's safe
to map memory region during hotplug/runtime.
That way hotplug path will have a chance to cancel
hotplug operation instead of crashing in vhost_commit().

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-10-22 14:34:48 +03:00
Changchun Ouyang 7263a0ad78 vhost-user: add a new message to disable/enable a specific virt queue.
Add a new message, VHOST_USER_SET_VRING_ENABLE, to enable or disable
a specific virt queue, which is similar to attach/detach queue for
tap device.

virtio driver on guest doesn't have to use max virt queue pair, it
could enable any number of virt queue ranging from 1 to max virt
queue pair.

Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:53 +03:00
Changchun Ouyang b931bfbf04 vhost-user: add multiple queue support
This patch is initially based a patch from Nikolay Nikolaev.

This patch adds vhost-user multiple queue support, by creating a nc
and vhost_net pair for each queue.

Qemu exits if find that the backend can't support the number of requested
queues (by providing queues=# option). The max number is queried by a
new message, VHOST_USER_GET_QUEUE_NUM, and is sent only when protocol
feature VHOST_USER_PROTOCOL_F_MQ is present first.

The max queue check is done at vhost-user initiation stage. We initiate
one queue first, which, in the meantime, also gets the max_queues the
backend supports.

In older version, it was reported that some messages are sent more times
than necessary. Here we came an agreement with Michael that we could
categorize vhost user messages to 2 types: non-vring specific messages,
which should be sent only once, and vring specific messages, which should
be sent per queue.

Here I introduced a helper function vhost_user_one_time_request(), which
lists following messages as non-vring specific messages:

        VHOST_USER_SET_OWNER
        VHOST_USER_RESET_DEVICE
        VHOST_USER_SET_MEM_TABLE
        VHOST_USER_GET_QUEUE_NUM

For above messages, we simply ignore them when they are not sent the first
time.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:53 +03:00
Yuanhan Liu fc57fd9900 vhost: introduce vhost_backend_get_vq_index method
Minusing the idx with the base(dev->vq_index) for vhost-kernel, and
then adding it back for vhost-user doesn't seem right. Here introduces
a new method vhost_backend_get_vq_index() for getting the right vq
index for following vhost messages calls.

Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:53 +03:00
Yuanhan Liu e2051e9e00 vhost-user: add VHOST_USER_GET_QUEUE_NUM message
This is for querying how many queues the backend supports if it has mq
support(when VHOST_USER_PROTOCOL_F_MQ flag is set from the quried
protocol features).

vhost_net_get_max_queues() is the interface to export that value, and
to tell if the backend supports # of queues user requested, which is
done in the following patch.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:52 +03:00
Yuanhan Liu d1f8b30ec8 vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE
Quote from Michael:

    We really should rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:52 +03:00
Michael S. Tsirkin dcb10c000c vhost-user: add protocol feature negotiation
Support a separate bitmask for vhost-user protocol features,
and messages to get/set protocol features.

Invoke them at init.

No features are defined yet.

[ leverage vhost_user_call for request handling -- Yuanhan Liu ]

Signed-off-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:52 +03:00
Yuanhan Liu 7305483a3d vhost-user: use VHOST_USER_XXX macro for switch statement
So that we could let vhost_user_call to handle extented requests,
such as VHOST_USER_GET/SET_PROTOCOL_FEATURES, instead of invoking
vhost_user_read/write and constructing the msg again by ourself.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
2015-09-24 16:27:52 +03:00
Michael S. Tsirkin d345ed2da3 Revert "vhost-user: add multi queue support"
This reverts commit 830d70db69.

The interface isn't fully backwards-compatible, which is bad.
Let's redo this properly after 2.4.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-20 14:19:40 +03:00
Ouyang Changchun 830d70db69 vhost-user: add multi queue support
Based on patch by Nikolay Nikolaev:
Vhost-user will implement the multi queue support in a similar way
to what vhost already has - a separate thread for each queue.
To enable the multi queue functionality - a new command line parameter
"queues" is introduced for the vhost-user netdev.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-01 14:18:55 +02:00
Gonglei ab7c5aaf31 vhost-user: remove superfluous '\n' around error_report()
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-04-30 16:06:17 +03:00
Michael S. Tsirkin d3f16ec887 vhost-user: fix mmap offset calculation
qemu_get_ram_block_host_ptr should get ram_addr_t,
vhost-user passes in GPA.
That's very wrong.

Reported-by: Linhaifeng <haifeng.lin@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-11-03 18:32:48 +02:00
Michael S. Tsirkin cd98639f67 vhost-user: minor cleanups
assert to verify cast does not discard information
minor style fixup.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-07-18 02:22:24 +03:00
Nikolay Nikolaev f69a28051f vhost-user: Fix VHOST_SET_MEM_TABLE processing
qemu_get_ram_fd doesn't accept a guest physical address. ram_addr_t are
opaque values that are assigned in qemu_ram_alloc.

Find the ram_addr_t corresponding to the userspace_addr using qemu_ram_addr_from_host,
and then call qemu_get_ram_fd on it.

Thanks to Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-18 02:14:15 +03:00
Damjan Marion 3fd74b8407 vhost-user: fix regions provied with VHOST_USER_SET_MEM_TABLE message
Old code was affected by memory gaps which resulted in buffer pointers
pointing to address outside of the mapped regions.

Here we are introducing following changes:
 - new function qemu_get_ram_block_host_ptr() returns host pointer
   to the ram block, it is needed to calculate offset of specific
   region in the host memory
 - new field mmap_offset is added to the VhostUserMemoryRegion. It
   contains offset where specific region starts in the mapped memory.
   As there is stil no wider adoption of vhost-user agreement was made
   that we will not bump version number due to this change
 - other fileds in VhostUserMemoryRegion struct are not changed, as
   they are all needed for usermode app implementation
 - region data is not taken from ram_list.blocks anymore, instead we
   use region data which is alredy calculated for use in vhost-net
 - Now multiple regions can have same FD and user applicaton can call
   mmap() multiple times with the same FD but with different offset
   (user needs to take care for offset page alignment)

Signed-off-by: Damjan Marion <damarion@cisco.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Damjan Marion <damarion@cisco.com>
2014-06-29 19:39:40 +03:00
Nikolay Nikolaev 5f6f6664bf Add vhost-user as a vhost backend.
The initialization takes a chardev backed by a unix domain socket.
It should implement qemu_fe_set_msgfds in order to be able to pass
file descriptors to the remote process.

Each ioctl request of vhost-kernel has a vhost-user message equivalent,
which is sent over the control socket.

The general approach is to copy the data from the supplied argument
pointer to a designated field in the message. If a file descriptor is
to be passed it will be placed in the fds array for inclusion in
the sendmsg control header.

VHOST_SET_MEM_TABLE ignores the supplied vhost_memory structure and scans
the global ram_list for ram blocks with a valid fd field set. This would
be set when the '-object memory-file' option with share=on property is used.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-19 16:41:56 +03:00