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>
