Separate the QEMUFile interface from the stdio-specific implementation,
to reduce dependencies from code using QEMUFile.
The code that is being moved is similar to the one that was on savevm.c before
it was moved in commit 093c455a8c, except for
some changes done by Markus, Juan, and myself. So, I am using the copyright and
license header from savevm.c, but CCing Juan and Markus so they can review the
copyright/license header.
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Separate the QEMUFile interface from the implementation, to reduce
dependencies from code using QEMUFile.
All the code that is being moved to the new file is exactly the same
code that was on savevm.c (moved by commit
093c455a8c), so I am using the copyright
and license header from savevm.c for the new file.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Use the existing function which checks if writev_buffer() or
put_buffer() are set, instead of duplicating it.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The QEMUFileStdio code will use qemu_file_is_writable() and will be
moved to a separate file.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The person who created qemu-file.c (me, on commit
093c455a8c) didn't add a copyright/license
header to the file, even though the whole code was copied from savevm.c
(which had a copyright/license header).
To correct this, copy the copyright information and license from
savevm.c, that's where the original code came from.
Luckily, very few changes were made on qemu-file.c after it was created.
All the authors who touched the code are being CCed, so they can confirm
if they are OK with the copyright/license information being added.
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This is based on Stefan and Joel's patch that creates a QEMUFile that goes
to a memory buffer; from:
http://lists.gnu.org/archive/html/qemu-devel/2013-03/msg05036.html
Using the QEMUFile interface, this patch adds support functions for
operating on in-memory sized buffers that can be written to or read from.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
For fixes/tweeks I've done:
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Make qemu_peek_buffer repeatedly call fill_buffer until it gets
all the data it requires, or until there is an error.
At the moment, qemu_peek_buffer will try one qemu_fill_buffer if there
isn't enough data waiting, however the kernel is entitled to return
just a few bytes, and still leave qemu_peek_buffer with less bytes
than it needed. I've seen this fail in a dev world, and I think it
could theoretically fail in the peeking of the subsection headers in
the current world.
Comment qemu_peek_byte to point out it's not guaranteed to work for
non-continuous peeks
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: ChenLiang <chenliang0016@icloud.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This replaces DPRINTF macro with tracepoints.
This moves some messages from migration.c to savevm.c.
This adds tracepoint to signal about fileds failed to migrate.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewers accepted v2 of the patch, but what got committed was v1,
with the R-bys for v2. This is the v1->v2 followup fix.
[Amit:
This fixes commit aded6539d9
]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
fwrite() returns the number of items written. But when there is one
error, it can return a short write.
In the particular bug that I was tracking, I did a migration to a
read-only filesystem. And it was able to finish the migration
correctly. fwrite() never returned a negative error code, nor zero,
always 4096. (migration writes chunks of about 14000 bytes). And it
was able to "complete" the migration with success (yes, reading the
file was a bit more difficult).
To add insult to injury, if your amount of memory was big enough (12GB
on my case), it overwrote some important structure, and from them,
malloc failed. This check makes the problem go away.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
