Introduce facilities for guest migration on top of vhost-user
infrastructure. Add migration facilities based on top of the current
vhost-user infrastructure, moving vu_migrate() and related functions
to migrate.c.
Versioned migration stages define function pointers to be called on
source or target, or data sections that need to be transferred.
The migration header consists of a magic number, a version number for the
encoding, and a "compat_version" which represents the oldest version which
is compatible with the current one. We don't use it yet, but that allows
for the future possibility of backwards compatible protocol extensions.
Co-authored-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Having every vhost-user message printed as part of debug output makes
debugging anything else a bit complicated.
Change per-packet debug() messages in vu_kick_cb() and
vu_send_single() to trace()
[dgibson: switch different messages to trace()]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
vu_remove_watch() is used in vhost_user.c to remove an fd from the global
epoll set. There's nothing really vhost user specific about it though,
so rename, move to util.c and use it in a bunch of places outside
vhost_user.c where it makes things marginally more readable.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
If the iovec array cannot be managed, drop it rather than
passing the second entry to tap_add_packet().
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Replace ASSERT() on the number of iovec in the element and on
the first entry length by a debug() message.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
[sbrivio: Fix typo in failure message]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Set the file descriptor to use to transfer the
backend device state during migration.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
[sbrivio: Fixed nits and coding style here and there]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
vu_dev will be needed to log page update.
Add the parameter to:
vring_used_write()
vu_queue_fill_by_index()
vu_queue_fill()
vring_used_idx_set()
vu_queue_flush()
The new parameter is unused for now.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Under some conditions, linux can provide several buffers
in the same element (multiple entries in the iovec array).
I didn't identify what changed between the kernel guest that
provides one buffer and the one that provides several
(doesn't seem to be a kernel change or a configuration change).
Fix the following assert:
ASSERTION FAILED in virtqueue_map_desc (virtio.c:402): num_sg < max_num_sg
What I can see is the buffer can be splitted in two iovecs:
- vnet header
- packet data
This change manages this special case but the real fix will be to allow
tap_add_packet() to manage iovec array.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We don't modify the structure in some virtio functions.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
add virtio and vhost-user functions to connect with QEMU.
$ ./passt --vhost-user
and
# qemu-system-x86_64 ... -m 4G \
-object memory-backend-memfd,id=memfd0,share=on,size=4G \
-numa node,memdev=memfd0 \
-chardev socket,id=chr0,path=/tmp/passt_1.socket \
-netdev vhost-user,id=netdev0,chardev=chr0 \
-device virtio-net,mac=9a:2b:2c:2d:2e:2f,netdev=netdev0 \
...
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: as suggested by lvivier, include <netinet/if_ether.h>
before including <linux/if_ether.h> as C libraries such as musl
__UAPI_DEF_ETHHDR in <netinet/if_ether.h> if they already have
a definition of struct ethhdr]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
