Hosts hold on to handles provided by guest-file-open for periods that can
span beyond the life of the qemu-ga process that issued them. Since these
are issued starting from 0 on every restart, we run the risk of issuing
duplicate handles after restarts/reboots.
As a result, users with a stale copy of these handles may end up
reading/writing corrupted data due to their existing handles effectively
being re-assigned to an unexpected file or offset.
We unfortunately do not issue handles as strings, but as integers, so a
solution such as using UUIDs can't be implemented without introducing a
new interface.
As a workaround, we fix this by implementing a persistent key-value store
that will be used to track the value of the last handle that was issued
across restarts/reboots to avoid issuing duplicates.
The store is automatically written to the same directory we currently
set via --statedir to track fsfreeze state, and so should be applicable
for stable releases where this flag is supported.
A follow-up can use this same store for handling fsfreeze state, but
that change is cosmetic and left out for now.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: qemu-stable@nongnu.org
* fixed guest_file_handle_add() return value from uint64_t to int64_t
We currently maintain a whitelist of commands that are safe during
fsfreeze. During fsfreeze, we disable all commands that aren't part of
that whitelist.
guest-sync-delimited meets the criteria for being whitelisted, and is
also required for qemu-ga clients that rely on guest-sync-delimited for
re-syncing the channel after a timeout.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Eric Blake <eblake@redhat.com>
In commit 7868e26e59
("qemu-ga: add initial win32 support") support was added for qemu-ga on
Windows using virtio-serial. Other channel methods (ISA serial and UNIX
domain socket) are not supported on Windows.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
This patch fixes a compiler warning when cross-build:
qga/service-win32.c: In function 'printf_win_error':
qga/service-win32.c:32:5: warning: format '%d' expects argument of type 'int',
but argument 3 has type 'DWORD' [-Wformat]
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
# By Paolo Bonzini (40) and others
# Via Juan Quintela
* quintela/migration.next: (46 commits)
page_cache: dup memory on insert
page_cache: fix memory leak
Fix cache_resize to keep old entry age
Fix page_cache leak in cache_resize
migration: inline migrate_fd_close
migration: eliminate s->migration_file
migration: move contents of migration_close to migrate_fd_cleanup
migration: move rate limiting to QEMUFile
migration: small changes around rate-limiting
migration: use qemu_ftell to compute bandwidth
migration: use QEMUFile for writing outgoing migration data
migration: use QEMUFile for migration channel lifetime
qemu-file: simplify and export qemu_ftell
qemu-file: add writable socket QEMUFile
qemu-file: check exit status when closing a pipe QEMUFile
qemu-file: fsync a writable stdio QEMUFile
migration: merge qemu_popen_cmd with qemu_popen
migration: use qemu_file_rate_limit consistently
migration: remove useless qemu_file_get_error check
migration: detect error before sleeping
...
A conflict was resolved the wrong way when merging commit 320ba5f (build:
always link device_tree.o into emulators if libfdt available, 2013-02-05).
This causes a build failure for the arm-softmmu target due to multiply
defined symbol.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1362997886-9470-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The nature of the kernel ABI for the get_robust_list and set_robust_list
syscalls means we cannot implement them in QEMU. Make get_robust_list
silently return ENOSYS rather than using the default "print message and
then fail ENOSYS" code path, in the same way we already do for
set_robust_list, and add a comment documenting why we do this.
This silences warnings which were being produced for emulating
even trivial programs like 'ls' in x86-64-on-x86-64.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Implement the accept4 syscall (which is identical to accept
but has an additional flags argument).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Implement the sendfile and sendfile64 syscalls. This implementation
passes all the LTP test cases for these syscalls.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
If the guest passes us a bogus negative length for an iovec, fail
EINVAL rather than proceeding blindly forward. This fixes some of
the error cases tests for readv and writev in the LTP.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The linux-user usage message attempts to line up the columns in
its table by calculating the maximum width of any item in them.
However for the 'Argument' column it was only accounting for the
length of the option switch (eg "-d"), not the additional example
text (eg "item[,...]"). This currently has no adverse effects
because the widest item in the column happens to be the argumentless
"-singlestep" option, but improving the "-d" option help to read
"-d item[,...]" exceeds that limit.
Fix this by correctly calculating maxarglen as the width of the
first column text including a possible option argument, and
adjusting its uses to match.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
The page cache frees all data on finish, on resize and
if there is collision on insert. So it should be the caches
responsibility to dup the data that is stored in the cache.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
XBZRLE encoded migration introduced a MRU page cache
meachnism. Unfortunately, cached items where never freed in
case of a collision in the page cache on cache_insert().
This lead to out of memory conditions during XBZRLE migration
if the page cache was small and there where a lot of collisions
in the cache.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Instead of using cache_insert do the update itself
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The indirection is useless now. Backends can open s->file directly.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
With this patch, the migration_file is not needed anymore.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Rate limiting is now simply a byte counter; client call
qemu_file_rate_limit() manually to determine if they have to exit.
So it is possible and simple to move the functionality to QEMUFile.
This makes the remaining functionality of s->file redundant;
in the next patch we can remove it and write directly to s->migration_file.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This patch extracts a few small changes from the next patch, which
are unrelated to adding generic rate-limiting functionality to
QEMUFile. Make migration_set_rate_limit a simple accessor, and
use qemu_file_set_rate_limit consistently. Also fix a typo where
INT_MAX should have been SIZE_MAX.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Prepare for when s->bytes_xfer will be removed.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Second, drop the file descriptor indirection, and write directly to the
QEMUFile.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
As a start, use QEMUFile to store the destination and close it.
qemu_get_fd gets a file descriptor that will be used by the write
callbacks.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Force a flush when qemu_ftell is called. This simplifies the buffer magic
(it also breaks qemu_ftell for input QEMUFiles, but we never use it).
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This is what exec_close does. Move this to the underlying QEMUFile.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This is what fd_close does. Prepare for switching to a QEMUFile.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
There is no reason for outgoing exec migration to do popen manually
anymore (the reason used to be that we needed the FILE* to make it
non-blocking). Use qemu_popen_cmd.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
migration_put_buffer is never called if there has been an error.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We will go around the loop exactly once after setting last_round.
Eliminate the variable altogether.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This is consistent once that we have moved everything to migration.c
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Buffering was needed because blocking writes could take a long time
and starve other threads seeking to grab the big QEMU mutex.
Now that all writes (except within _complete callbacks) are done
outside the big QEMU mutex, we do not need buffering at all.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Only the migration_bitmap_sync() call needs the iothread lock.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This makes it possible to do blocking writes directly to the socket,
with no buffer in the middle. For RAM, only the migration_bitmap_sync()
call needs the iothread lock. For block migration, it is needed by
the block layer (including bdrv_drain_all and dirty bitmap access),
but because some code is shared between iterate and complete, all of
mig_save_device_dirty is run with the lock taken.
In the savevm case, the iterate callback runs within the big lock.
This is annoying because it complicates the rules. Luckily we do not
need to do anything about it: the RAM iterate callback does not need
the iothread lock, and block migration never runs during savevm.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This groups together the callbacks that later will have similar
locking rules.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Some state is shared between the block migration code and its AIO
callbacks. Once block migration will run outside the iothread,
the block migration code and the AIO callbacks will be able to
run concurrently. Protect the critical sections with a separate
lock. Do the same for completed_sectors, which can be used from
the monitor.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Some small changes that will simplify the positioning of lock/unlock
primitives.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Perform final cleanup in a bottom half, and add joining the thread to
the series of cleanup actions.
migrate_fd_error remains for connection error, but it doesn't need
to cleanup anything anymore.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Accessing s->state outside the big QEMU lock will simplify a bit the
locking/unlocking of the iothread lock.
We need to keep the lock in migrate_fd_error and migrate_fd_completed,
however, because they call migrate_fd_cleanup.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Completion of migration is currently done with a "nested" loop that
invokes buffered_flush: migrate_fd_completed is called by
buffered_file_thread, which calls migrate_fd_cleanup, which calls
buffered_close (via qemu_fclose), which flushes the buffer.
Simplify this, by reusing the buffered_flush call of buffered_file_thread.
Then if qemu_savevm_state_complete was called, and the buffer is empty
(including the QEMUFile buffer, for which we need the previous patch), we
are done.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Always use qemu_file_get_error to detect errors, since that is how
QEMUFile itself drops I/O after an error occurs. There is no need
to propagate and check return values all the time.
Also remove the "complete" member, since we know that it is set (via
migrate_fd_cleanup) only when the state changes.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Remove the return value of buffered_flush, pass it via the error code
of s->file. Once this is done, the error can be retrieved simply
via migrate_fd_close's call to qemu_fclose.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Including data that resided in the QEMUFile's own buffer.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Right now, migration cannot entirely rely on QEMUFile's automatic
drop of I/O after an error, because it does its "real" I/O outside
the put_buffer callback. To fix this until buffering is gone, expose
qemu_file_set_error which we will use in buffered_flush.
Similarly, buffered_flush is not a complete flush because some data may
still reside in the QEMUFile's own buffer. This somewhat complicates the
process of closing the migration thread. Again, when buffering is gone
buffered_flush will disappear and calling qemu_fflush will not be needed;
in the meanwhile, we expose the function for use in migration.c.
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
