Commit Graph

106 Commits

Author SHA1 Message Date
Daniel P. Berrangé
2893a2884b migration: hardcode assumption that QEMUFile is backed with QIOChannel
The only callers of qemu_fopen_ops pass 'true' for the 'has_ioc'
parameter, so hardcode this assumption in QEMUFile, by passing in
the QIOChannel object as a non-opaque parameter.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
   dgilbert: Fixed long line
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
365c0463db migration: stop passing 'opaque' parameter to QEMUFile hooks
The only user of the hooks is RDMA which provides a QIOChannel backed
impl of QEMUFile. It can thus use the qemu_file_get_ioc() method.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
bc698c367d migration: rename qemu_file_update_transfer to qemu_file_acct_rate_limit
The qemu_file_update_transfer name doesn't give a clear guide on what
its purpose is, and how it differs from the qemu_file_credit_transfer
method. The latter is specifically for accumulating for total migration
traffic, while the former is specifically for accounting in thue rate
limit calculations. The new name give better guidance on its usage.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
1a93bd2f60 migration: rename qemu_update_position to qemu_file_credit_transfer
The qemu_update_position method name gives the misleading impression
that it is changing the current file offset. Most of the files are
just streams, however, so there's no concept of a file offset in the
general case.

What this method is actually used for is to report on the number of
bytes that have been transferred out of band from the main I/O methods.
This new name better reflects this purpose.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
fbfa6404e5 migration: rename qemu_ftell to qemu_file_total_transferred
The name 'ftell' gives the misleading impression that the QEMUFile
objects are seekable. This is not the case, as in general we just
have an opaque stream. The users of this method are only interested
in the total bytes processed. This switches to a new name that
reflects the intended usage.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
   dgilbert: Wrapped long line
2022-06-22 19:33:36 +01:00
Daniel P. Berrangé
154d87b4ef migration: rename 'pos' field in QEMUFile to 'bytes_processed'
The field name 'pos' gives the misleading impression that the QEMUFile
objects are seekable. This is not the case, as in general we just
have an opaque stream. The users of this method are only interested
in the total bytes processed. This switches to a new name that
reflects the intended usage.

Every QIOChannel backed impl of QEMUFile is currently ignoring the
'pos' field.

The only QEMUFile impl using 'pos' as an offset for I/O is the block
device vmstate. A later patch is introducing a QIOChannel impl for the
vmstate, and to handle this it is tracking a file offset itself
internally to the QIOChannel impl. So when we later eliminate the
QEMUFileOps callbacks later, the 'pos' field will no longer be used
from any I/O read/write methods.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Fixed long line
2022-06-22 18:59:38 +01:00
Daniel P. Berrangé
c7fc8d323a migration: rename rate limiting fields in QEMUFile
This renames the following QEMUFile fields

 * bytes_xfer -> rate_limit_used
 * xfer_limit -> rate_limit_max

The intent is to make it clear that 'bytes_xfer' is specifically related
to rate limiting of data and applies to data queued, which need not have
been transferred on the wire yet if a flush hasn't taken place.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-22 18:11:21 +01:00
Peter Maydell
b85ea5fa2f include: Move qemu_madvise() and related #defines to new qemu/madvise.h
The function qemu_madvise() and the QEMU_MADV_* constants associated
with it are used in only 10 files.  Move them out of osdep.h to a new
qemu/madvise.h header that is included where it is needed.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220208200856.3558249-2-peter.maydell@linaro.org
2022-02-21 13:30:20 +00:00
Peter Xu
c6ad5be7ae migration: Teach QEMUFile to be QIOChannel-aware
migration uses QIOChannel typed qemufiles.  In follow up patches, we'll need
the capability to identify this fact, so that we can get the backing QIOChannel
from a QEMUFile.

We can also define types for QEMUFile but so far since we only need to be able
to identify QIOChannel, introduce a boolean which is simpler.

Introduce another helper qemu_file_get_ioc() to return the ioc backend of a
qemufile if has_ioc is set.

No functional change.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210722175841.938739-5-peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-07-26 12:44:59 +01:00
Feng Lin
c00d434ac6 migration: fix the memory overwriting risk in add_to_iovec
When testing migration, a Segmentation fault qemu core is generated.
0  error_free (err=0x1)
1  0x00007f8b862df647 in qemu_fclose (f=f@entry=0x55e06c247640)
2  0x00007f8b8516d59a in migrate_fd_cleanup (s=s@entry=0x55e06c0e1ef0)
3  0x00007f8b8516d66c in migrate_fd_cleanup_bh (opaque=0x55e06c0e1ef0)
4  0x00007f8b8626a47f in aio_bh_poll (ctx=ctx@entry=0x55e06b5a16d0)
5  0x00007f8b8626e71f in aio_dispatch (ctx=0x55e06b5a16d0)
6  0x00007f8b8626a33d in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>)
7  0x00007f8b866bdba4 in g_main_context_dispatch ()
8  0x00007f8b8626cde9 in glib_pollfds_poll ()
9  0x00007f8b8626ce62 in os_host_main_loop_wait (timeout=<optimized out>)
10 0x00007f8b8626cffd in main_loop_wait (nonblocking=nonblocking@entry=0)
11 0x00007f8b862ef01f in main_loop ()
Using gdb print the struct QEMUFile f = {
  ...,
  iovcnt = 65, last_error = 21984,
  last_error_obj = 0x1, shutdown = true
}
Well iovcnt is overflow, because the max size of MAX_IOV_SIZE is 64.
struct QEMUFile {
    ...;
    struct iovec iov[MAX_IOV_SIZE];
    unsigned int iovcnt;
    int last_error;
    Error *last_error_obj;
    bool shutdown;
};
iovcnt and last_error is overwrited by add_to_iovec().
Right now, add_to_iovec() increase iovcnt before check the limit.
And it seems that add_to_iovec() assumes that iovcnt will set to zero
in qemu_fflush(). But qemu_fflush() will directly return when f->shutdown
is true.

The situation may occur when libvirtd restart during migration, after
f->shutdown is set, before calling qemu_file_set_error() in
qemu_file_shutdown().

So the safiest way is checking the iovcnt before increasing it.

Signed-off-by: Feng Lin <linfeng23@huawei.com>
Message-Id: <20210625062138.1899-1-linfeng23@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Fix typo in 'writeable' which is actually misnamed 'writable'
2021-07-05 10:51:26 +01:00
Wainer dos Santos Moschetta
1dfafcbd39 migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
as shown here:

../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  604 |             *buf = src;
      |             ~~~~~^~~~~
cc1: all warnings being treated as errors

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-Id: <20210128130625.569900-1-wainersm@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-08 11:19:51 +00:00
Eric Blake
f9919116b8 osdep: Make MIN/MAX evaluate arguments only once
I'm not aware of any immediate bugs in qemu where a second runtime
evaluation of the arguments to MIN() or MAX() causes a problem, but
proactively preventing such abuse is easier than falling prey to an
unintended case down the road.  At any rate, here's the conversation
that sparked the current patch:
https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg05718.html

Update the MIN/MAX macros to only evaluate their argument once at
runtime; this uses typeof(1 ? (a) : (b)) to ensure that we are
promoting the temporaries to the same type as the final comparison (we
have to trigger type promotion, as typeof(bitfield) won't compile; and
we can't use typeof((a) + (b)) or even typeof((a) + 0), as some of our
uses of MAX are on void* pointers where such addition is undefined).

However, we are unable to work around gcc refusing to compile ({}) in
a constant context (such as the array length of a static variable),
even when only used in the dead branch of a __builtin_choose_expr(),
so we have to provide a second macro pair MIN_CONST and MAX_CONST for
use when both arguments are known to be compile-time constants and
where the result must also be usable as a constant; this second form
evaluates arguments multiple times but that doesn't matter for
constants.  By using a void expression as the expansion if a
non-constant is presented to this second form, we can enlist the
compiler to ensure the double evaluation is not attempted on
non-constants.

Alas, as both macros now rely on compiler intrinsics, they are no
longer usable in preprocessor #if conditions; those will just have to
be open-coded or the logic rewritten into #define or runtime 'if'
conditions (but where the compiler dead-code-elimination will probably
still apply).

I tested that both gcc 10.1.1 and clang 10.0.0 produce errors for all
forms of macro mis-use.  As the errors can sometimes be cryptic, I'm
demonstrating the gcc output:

Use of MIN when MIN_CONST is needed:

In file included from /home/eblake/qemu/qemu-img.c:25:
/home/eblake/qemu/include/qemu/osdep.h:249:5: error: braced-group within expression allowed only inside a function
  249 |     ({                                                  \
      |     ^
/home/eblake/qemu/qemu-img.c:92:12: note: in expansion of macro ‘MIN’
   92 | char array[MIN(1, 2)] = "";
      |            ^~~

Use of MIN_CONST when MIN is needed:

/home/eblake/qemu/qemu-img.c: In function ‘is_allocated_sectors’:
/home/eblake/qemu/qemu-img.c:1225:15: error: void value not ignored as it ought to be
 1225 |             i = MIN_CONST(i, n);
      |               ^

Use of MIN in the preprocessor:

In file included from /home/eblake/qemu/accel/tcg/translate-all.c:20:
/home/eblake/qemu/accel/tcg/translate-all.c: In function ‘page_check_range’:
/home/eblake/qemu/include/qemu/osdep.h:249:6: error: token "{" is not valid in preprocessor expressions
  249 |     ({                                                  \
      |      ^

Fix the resulting callsites that used #if or computed a compile-time
constant min or max to use the new macros.  cpu-defs.h is interesting,
as CPU_TLB_DYN_MAX_BITS is sometimes used as a constant and sometimes
dynamic.

It may be worth improving glib's MIN/MAX definitions to be saner, but
that is a task for another day.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200625162602.700741-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-26 09:39:39 -04:00
Wei Yang
42d24611af migration/compress: compress QEMUFile is not writable
We open a file with empty_ops for compress QEMUFile, which means this is
not writable.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-29 11:28:59 +01:00
Juan Quintela
a555b8092a qemu-file: Don't do IO after shutdown
Be sure that we are not doing neither read/write after shutdown of the
QEMUFile.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-29 11:28:59 +01:00
Wei Yang
1bf57fb3df migration/qemu-file: fix potential buf waste for extra buf_index adjustment
In add_to_iovec(), qemu_fflush() will be called if iovec is full. If
this happens, buf_index is reset. Currently, this is not checked and
buf_index would always been adjust with buf size.

This is not harmful, but will waste some space in file buffer.

This patch make add_to_iovec() return 1 when it has flushed the file.
Then the caller could check the return value to see whether it is
necessary to adjust the buf_index any more.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Message-Id: <20190911132839.23336-3-richard.weiyang@gmail.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-09-12 11:23:32 +01:00
Wei Yang
89fe04b458 migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data
The check of writev_buffer is in qemu_fflush, which means it is not
harmful if it is NULL.

And removing it will make the code consistent since all other
add_to_iovec() is called without the check.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190911132839.23336-2-richard.weiyang@gmail.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-09-12 11:23:26 +01:00
Dr. David Alan Gilbert
3b34870672 qemu-file: Rework old qemu_fflush comment
Commit 11808bb removed the non-iovec based write support,
the comment hung on.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190823103946.7388-1-dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-09-12 11:16:10 +01:00
Ivan Ren
5d7d255863 migration: add qemu_file_update_transfer interface
Add qemu_file_update_transfer for just update bytes_xfer for speed
limitation. This will be used for further migration feature such as
multifd migration.

Signed-off-by: Ivan Ren <ivanren@tencent.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1564464816-21804-2-git-send-email-ivanren@tencent.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-08-14 17:33:14 +01:00
Yury Kotov
3d661c8ab1 migration: Add error_desc for file channel errors
Currently, there is no information about error if outgoing migration was failed
because of file channel errors.
Example (QMP session):
-> { "execute": "migrate", "arguments": { "uri": "exec:head -c 1" }}
<- { "return": {} }
...
-> { "execute": "query-migrate" }
<- { "return": { "status": "failed" }} // There is not error's description

And even in the QEMU's output there is nothing.

This patch
1) Adds errp for the most of QEMUFileOps
2) Adds qemu_file_get_error_obj/qemu_file_set_error_obj
3) And finally using of qemu_file_get_error_obj in migration.c

And now, the status for the mentioned fail will be:
-> { "execute": "query-migrate" }
<- { "return": { "status": "failed",
                 "error-desc": "Unable to write to command: Broken pipe" }}

Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru>
Message-Id: <20190422103420.15686-1-yury-kotov@yandex-team.ru>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-08-14 17:33:14 +01:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Lidong Chen
ccb7e1b5a6 migration: disable RDMA WRITE after postcopy started
RDMA WRITE operations are performed with no notification to the destination
qemu, then the destination qemu can not wakeup. This patch disable RDMA WRITE
after postcopy started.

Signed-off-by: Lidong Chen <lidongchen@tencent.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2018-08-22 12:12:07 +02:00
Xiao Guangrong
34ab9e9743 migration: detect compression and decompression errors
Currently the page being compressed is allowed to be updated by
the VM on the source QEMU, correspondingly the destination QEMU
just ignores the decompression error. However, we completely miss
the chance to catch real errors, then the VM is corrupted silently

To make the migration more robuster, we copy the page to a buffer
first to avoid it being written by VM, then detect and handle the
errors of both compression and decompression errors properly

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180330075128.26919-5-xiaoguangrong@tencent.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-04-25 18:04:08 +01:00
Xiao Guangrong
dcaf446ebd migration: stop compression to allocate and free memory frequently
Current code uses compress2() to compress memory which manages memory
internally, that causes huge memory is allocated and freed very
frequently

More worse, frequently returning memory to kernel will flush TLBs
and trigger invalidation callbacks on mmu-notification which
interacts with KVM MMU, that dramatically reduce the performance
of VM

So, we maintain the memory by ourselves and reuse it for each
compression

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180330075128.26919-3-xiaoguangrong@tencent.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-04-25 18:04:06 +01:00
Lidong Chen
e8a0f2f9a1 migration: Fix rate limiting issue on RDMA migration
RDMA migration implement save_page function for QEMUFile, but
ram_control_save_page do not increase bytes_xfer. So when doing
RDMA migration, it will use whole bandwidth.

Signed-off-by: Lidong Chen <lidongchen@tencent.com>
Message-Id: <1520692378-1835-1-git-send-email-lidongchen@tencent.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2018-03-23 16:37:15 +00:00
Vladimir Sementsov-Ogievskiy
f0d64cb729 migration/qemu-file: add qemu_put_counted_string()
Add function opposite to qemu_get_counted_string.
qemu_put_counted_string puts one-byte length of the string (string
should not be longer than 255 characters), and then it puts the string,
without last zero byte.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180313180320.339796-9-vsementsov@virtuozzo.com
2018-03-13 17:05:55 -04:00
Juan Quintela
1adc1ceef7 migration: Remove unneeded includes
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
2017-06-14 11:10:19 +02:00
Juan Quintela
6666c96aac migration: Move migration.h to migration/
Nothing uses it outside of migration.h

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2017-06-13 11:00:45 +02:00
Juan Quintela
08a0aee15c migration: Split qemu-file.h
Split the file into public and internal interfaces.  I have to rename
the external one because we can't have two include files with the same
name in the same directory.  Build system gets confused.  The only
exported functions are the ones that handle basic types.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-06-01 18:49:22 +02:00
Pavel Butsykin
53f09a1076 add 'release-ram' migrate capability
This feature frees the migrated memory on the source during postcopy-ram
migration. In the second step of postcopy-ram migration when the source vm
is put on pause we can free unnecessary memory. It will allow, in particular,
to start relaxing the memory stress on the source host in a load-balancing
scenario.

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Message-Id: <20170203152321.19739-3-pbutsykin@virtuozzo.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
   Manually merged in Pavel's 'migration: madvise error_report fixup!'
2017-02-13 17:27:13 +00:00
Liang Li
787d134fb1 migration: fix live migration failure with compression
Because of commit 11808bb0c4, which remove some condition checks
of 'f->ops->writev_buffer', 'qemu_put_qemu_file' should be enhanced
to clear the 'f_src->iovcnt', or 'f_src->iovcnt' may exceed the
MAX_IOV_SIZE which will break live migration. This should be fixed.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reported-by: Jinshi Zhang <jinshi.c.zhang@intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1470702146-24399-1-git-send-email-liang.z.li@intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-08-11 16:59:53 +05:30
Liang Li
b3be28969b qemu-file: Fix qemu_put_compression_data flaw
Current qemu_put_compression_data can only work with no writable
QEMUFile, and can't work with the writable QEMUFile. But it does
not provide any measure to prevent users from using it with a
writable QEMUFile.

We should fix this flaw to make it works with writable QEMUFile.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Suggested-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1462433579-13691-5-git-send-email-liang.z.li@intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-06-17 18:24:18 +05:30
Daniel P. Berrange
12992c16d9 migration: remove qemu_get_fd method from QEMUFile
Now that there is a set_blocking callback in QEMUFileOps,
and all users needing non-blocking support have been
converted to QIOChannel, there is no longer any codepath
requiring the qemu_get_fd() method for QEMUFile. Remove it
to avoid further code being introduced with an expectation
of direct file handle access.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1461751518-12128-29-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:32:21 +05:30
Daniel P. Berrange
11808bb0c4 migration: remove support for non-iovec based write handlers
All the remaining QEMUFile implementations provide an iovec
based write handler, so the put_buffer callback can be removed
to simplify the code.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1461751518-12128-28-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:32:18 +05:30
Daniel P. Berrange
a24939f279 migration: move definition of struct QEMUFile back into qemu-file.c
Now that the memory buffer based QEMUFile impl is gone, there
is no need for any backend to be accessing internals of the
QEMUFile struct, so it can be moved back into qemu-file.c

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1461751518-12128-24-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:32:05 +05:30
Daniel P. Berrange
06ad513532 migration: introduce set_blocking function in QEMUFileOps
Remove the assumption that every QEMUFile implementation has
a file descriptor available by introducing a new function
in QEMUFileOps to change the blocking state of a QEMUFile.

If not set, it will fallback to the original code using
the get_fd method.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-7-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:31:19 +05:30
Daniel P. Berrange
0436e09f96 migration: split migration hooks out of QEMUFileOps
The QEMUFileOps struct contains the I/O subsystem callbacks
and the migration stage hooks. Split the hooks out into a
separate QEMUFileHooks struct to make it easier to refactor
the I/O side of QEMUFile without affecting the hooks.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-6-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:31:16 +05:30
Daniel P. Berrange
baf51e7739 migration: ensure qemu_fflush() always writes full data amount
The QEMUFile writev_buffer / put_buffer functions are expected
to write out the full set of requested data, blocking until
complete. The qemu_fflush() caller does not expect to deal with
partial writes. Clarify the function comments and add a sanity
check to the code to catch mistaken implementations.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-5-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-05-26 11:31:14 +05:30
Peter Maydell
1393a48526 migration: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-2-git-send-email-peter.maydell@linaro.org
2016-01-29 15:07:22 +00:00
Dr. David Alan Gilbert
adc468e9b9 Return path: Open a return path on QEMUFile for sockets
Postcopy needs a method to send messages from the destination back to
the source, this is the 'return path'.

Wire it up for 'socket' QEMUFile's.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:49 +01:00
Dr. David Alan Gilbert
a800cd5c38 Add wrapper for setting blocking status on a QEMUFile
Add a wrapper to change the blocking status on a QEMUFile
rather than having to use qemu_set_block(qemu_get_fd(f));
it seems best to avoid exposing the fd since not all QEMUFile's
really have one.  With this wrapper we could move the implementation
down to be different on different transports.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Dr. David Alan Gilbert
9504fb510c Add qemu_get_buffer_in_place to avoid copies some of the time
qemu_get_buffer always copies the data it reads to a users buffer,
however in many cases the file buffer inside qemu_file could be given
back to the caller, avoiding the copy.  This isn't always possible
depending on the size and alignment of the data.

Thus 'qemu_get_buffer_in_place' either copies the data to a supplied
buffer or updates a pointer to the internal buffer if convenient.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Daniel P. Berrange
10817bf09d coroutine: move into libqemuutil.a library
The coroutine files are currently referenced by the block-obj-y
variable. The coroutine functionality though is already used by
more than just the block code. eg migration code uses coroutine
yield. In the future the I/O channel code will also use the
coroutine yield functionality. Since the coroutine code is nicely
self-contained it can be easily built as part of the libqemuutil.a
library, making it widely available.

The headers are also moved into include/qemu, instead of the
include/block directory, since they are now part of the util
codebase, and the impl was never in the block/ directory
either.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-10-20 14:59:04 +01:00
Markus Armbruster
97f3ad3551 migration: Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).  Same Coccinelle semantic patch as in commit b45c03f.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1442231491-23352-1-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:36:35 +05:30
Dr. David Alan Gilbert
56f3835ff1 migration: qemu-file more size_t'ifying
This time convert the external functions:
  qemu_get_buffer, qemu_peek_buffer
  qemu_put_buffer and qemu_put_buffer_async

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1439463094-5394-6-git-send-email-dgilbert@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:33:02 +05:30
Dr. David Alan Gilbert
632e3a5cd8 Rework ram_control_load_hook to hook during block load
We need the names of RAMBlocks as they're loaded for RDMA,
reuse a slightly modified ram_control_load_hook:
  a) Pass a 'data' parameter to use for the name in the block-reg
     case
  b) Only some hook types now require the presence of a hook function.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:48 +02:00
Markus Armbruster
d49b683644 qerror: Move #include out of qerror.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:40 +02:00
Dr. David Alan Gilbert
7c1e52ba6f Move copy out of qemu_peek_buffer
qemu_peek_buffer currently copies the data it reads into a buffer,
however a future patch wants access to the buffer without the copy,
hence rework to remove the copy to the layer above.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-06-12 06:54:01 +02:00
Dr. David Alan Gilbert
b3af1bc9d2 Add qemu_get_counted_string to read a string prefixed by a count byte
and use it in loadvm_state and ram_load.

Where ever it's used, check the return and error if it failed.

Minor: ram_load was using a 257 byte array for its string, the
       maximum length is 255 bytes + 0 terminator, so fix to 256

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-06-12 06:54:01 +02:00
Liang Li
44f0eadc33 qemu-file: Add compression functions to QEMUFile
qemu_put_compression_data() compress the data and put it to QEMUFile.
qemu_put_qemu_file() put the data in the buffer of source QEMUFile to
destination QEMUFile.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-05-06 17:36:57 +02:00
Juan Quintela
6e1dea46b8 ram: make all save_page functions take a uint64_t parameter
It used to be an int, but then we can't pass directly the
bytes_transferred parameter, that would happen later in the series.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
2015-03-16 14:32:47 +01:00
Alexander Graf
9722140011 qemu-file: Add fast ftell code path
For ftell we flush the output buffer to ensure that we don't have anything
lingering in our internal buffers. This is a very safe thing to do.

However, with the dynamic size measurement that the dynamic vmstate
description will bring this would turn out quite slow.

Instead, we can fast path this specific measurement and just take the
internal buffers into account when telling the kernel our position.

I'm sure I overlooked some corner cases where this doesn't work, so
instead of tuning the safe, existing version, this patch adds a fast
variant of ftell that gets used by the dynamic vmstate description code
which isn't critical when it fails.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-02-05 17:16:14 +01:00
Dr. David Alan Gilbert
e1a8c9b67f socket shutdown
Add QEMUFile interface to allow a socket to be 'shut down' - i.e. any
reads/writes will fail (and any blocking read/write will be woken).

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-01-16 13:06:17 +05:30
Peter Maydell
90d6a6730b migration/qemu-file.c: Don't shift left into sign bit
Add a cast in qemu_get_be32() to avoid shifting left into the sign
bit of a signed integer (which is undefined behaviour in C).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-01-15 10:44:13 +03:00
Dr. David Alan Gilbert
977184db39 Split the QEMU buffered file code out
The splitting of qemu-file and addition of the buffered file landed
at the same time; so now split the buffered file code out.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2014-12-16 17:47:36 +05:30
Dr. David Alan Gilbert
4f9d090012 Split struct QEMUFile out
Now we've got multiple QEMUFile source files, some of them need
access to things that were defined in qemu-file.c, so create
a -internal header for them.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2014-12-16 17:47:36 +05:30
Dr. David Alan Gilbert
60fe637bf0 Start migrating migration code into a migration directory
The migration code now occupies a fair chunk of the top level .c
files, it seems time to give it it's own directory.

I've not touched:
   arch_init.c - that's mostly RAM migration but has a few random other
                 bits
   savevm.c    - because it's built target specific

This is purely a code move; no code has changed.
   - it fails checkpatch because of old violations, it feels safer
     to keep this as purely a move and fix those at some mythical future
     date.

The xbzrle and vmstate tests are now only run for softmmu builds
since they require files in the migrate/ directory which is only built
for softmmu.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2014-12-16 17:47:36 +05:30