Commit Graph

8 Commits

Author SHA1 Message Date
Marc-André Lureau
19409df883 libvhost-user: improve vu_queue_pop() doc
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-10-10 23:31:08 +02:00
Marc-André Lureau
eb078a9f0c libvhost-user: drop dependency on glib
libvhost-user is meant to be free of glib dependency. Make sure it is
by droping qemu/osdep.h (which included glib.h)

This fixes a bad malloc()/g_free() pair.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-10-10 23:31:08 +02:00
Marc-André Lureau
35480cbfcb libvhost-user: support resuming vq->last_avail_idx based on used_idx
This is the same workaround as commit 523b018dde, which was lost
with libvhost-user transition in commit e10e798c85.

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>
2017-09-08 16:15:17 +03:00
Jens Freimann
2566378d6d libvhost-user: quit when no more data received
End processing of messages when VHOST_USER_NONE
is received.

Without this we run into a vubr_panic() call and get
"PANIC: Unhandled request: 0"

Signed-off-by: Jens Freimann <jfreiman@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-08-09 04:22:13 +03:00
Felipe Franciosi
49cc0340f8 vhost-user-scsi: Introduce a vhost-user-scsi sample application
This commit introduces a vhost-user-scsi backend sample application. It
must be linked with libiscsi and libvhost-user.

To use it, compile with:
  $ make vhost-user-scsi

And run as follows:
  $ ./vhost-user-scsi -u vus.sock -i iscsi://uri_to_target/
  $ qemu-system-x86_64 --enable-kvm -m 512 \
      -object memory-backend-file,id=mem,size=512m,share=on,mem-path=guestmem \
      -numa node,memdev=mem \
      -chardev socket,id=vhost-user-scsi,path=vus.sock \
      -device vhost-user-scsi-pci,chardev=vhost-user-scsi \

The application is currently limited at one LUN only and it processes
requests synchronously (therefore only achieving QD1). The purpose of
the code is to show how a backend can be implemented and to test the
vhost-user-scsi Qemu implementation.

If a different instance of this vhost-user-scsi application is executed
at a remote host, a VM can be live migrated to such a host.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Message-Id: <1488479153-21203-5-git-send-email-felipe@nutanix.com>
2017-06-15 11:18:40 +02:00
Marc-André Lureau
640601c7cb libvhost-user: fix crash when rings aren't ready
Calling libvhost-user functions like vu_queue_get_avail_bytes() when the
queue doesn't yet have addresses will result in the crashes like the
following:

Program received signal SIGSEGV, Segmentation fault.
0x000055c414112ce4 in vring_avail_idx (vq=0x55c41582fd68, vq=0x55c41582fd68)
    at /home/dgilbert/git/qemu/contrib/libvhost-user/libvhost-user.c:940
940            vq->shadow_avail_idx = vq->vring.avail->idx;
(gdb) p vq
$1 = (VuVirtq *) 0x55c41582fd68
(gdb) p vq->vring
$2 = {num = 0, desc = 0x0, avail = 0x0, used = 0x0, log_guest_addr = 0, flags = 0}

    at /home/dgilbert/git/qemu/contrib/libvhost-user/libvhost-user.c:940
No locals.
    at /home/dgilbert/git/qemu/contrib/libvhost-user/libvhost-user.c:960
        num_heads = <optimized out>
    out_bytes=out_bytes@entry=0x7fffd035d7c4, max_in_bytes=max_in_bytes@entry=0,
    max_out_bytes=max_out_bytes@entry=0) at /home/dgilbert/git/qemu/contrib/libvhost-user/libvhost-user.c:1034

Add a pre-condition checks on vring.avail before accessing it.

Fix documentation and return type of vu_queue_empty() while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-05-10 22:04:23 +03:00
Felipe Franciosi
eae0f54334 libvhost-user: replace vasprintf() to fix build
On gcc 3.4 and newer, simply using (void) in front of WUR functions is
not sufficient to ignore the return value. That prevents a build when
handling warnings as errors.

libvhost-user had a usage of (void)vasprintf() which triggered such a
condition. This fixes it by replacing this call with g_strdup_vprintf()
which aborts on OOM.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Message-Id: <1488479153-21203-2-git-send-email-felipe@nutanix.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-05 12:10:00 +02:00
Marc-André Lureau
7b2e5c65f4 contrib: add libvhost-user
Add a library to help implementing vhost-user backend (or slave).

Dealing with vhost-user as an application developer isn't so easy: you
have all the trouble with any protocol: validation, unix ancillary data,
shared memory, eventfd, logging, and on top of that you need to deal
with virtio queues, if possible efficiently.

qemu test has a nice vhost-user testing application vhost-user-bridge,
which implements most of vhost-user, and virtio.c which implements
virtqueues manipulation. Based on these two, I tried to make a simple
library, reusable for tests or development of new vhost-user scenarios.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[Felipe: set used_idx copy on SET_VRING_ADDR and update shadow avail idx
 on SET_VRING_BASE]
Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-12-16 01:14:38 +02:00