We should not load PVM's state directly into SVM, because there maybe some
errors happen when SVM is receving data, which will break SVM.

We need to ensure receving all data before load the state into SVM. We use
an extra memory to cache these data (PVM's ram). The ram cache in secondary side
is initially the same as SVM/PVM's memory. And in the process of checkpoint,
we cache the dirty pages of PVM into this ram cache firstly, so this ram cache
always the same as PVM's memory at every checkpoint, then we flush this cached ram
to SVM after we receive all PVM's state.
Signed-off-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NLi Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: NZhang Chen <zhangckid@gmail.com>
Signed-off-by: NZhang Chen <chen.zhang@intel.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>

Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this:

migration/ram.c:651:19: warning: taking address of packed member 'magic' of class or structure 'MultiFDInit_t' may result in an unaligned pointer value [-Waddress-of-packed-member]
migration/ram.c:652:19: warning: taking address of packed member 'version' of class or structure 'MultiFDInit_t' may result in an unaligned pointer value [-Waddress-of-packed-member]
migration/ram.c:737:19: warning: taking address of packed member 'magic' of class or structure 'MultiFDPacket_t' may result in an unaligned pointer value [-Waddress-of-packed-member]
migration/ram.c:745:19: warning: taking address of packed member 'version' of class or structure 'MultiFDPacket_t' may result in an unaligned pointer value [-Waddress-of-packed-member]
migration/ram.c:755:19: warning: taking address of packed member 'size' of class or structure 'MultiFDPacket_t' may result in an unaligned pointer value [-Waddress-of-packed-member]

Avoid the bug by not using the "modify in place" byteswapping
functions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Message-Id: <20180925161924.7832-1-peter.maydell@linaro.org>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Add judgement in compress_threads_save_cleanup() to check whether the
static CompressParam *comp_param has been allocated. If not, just
return; or else segmentation fault will occur when using the NULL
comp_param's parameters.  One test case can reproduce this is: set
the compression on and migrate to a wrong nonexistent host IP address.

Our current code does not judge before handling comp_param[idx]'s quit
and cond that whether they have been initialized. If not initialized,
"qemu_mutex_lock_impl: Assertion `mutex->initialized' failed." will
occur. Fix this by squashing the terminate_compression_threads() into
compress_threads_save_cleanup() and employing the existing judgement
condition.  One test case can reproduce this error is: set the
compression on and fail to fully setup the default eight compression
thread in compress_threads_save_setup().
Signed-off-by: NFei Li <fli@suse.com>
Message-Id: <20180925091440.18910-1-fli@suse.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

It avoids to touch compression locks if xbzrle and compression
are both enabled
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Message-Id: <20180906070101.27280-4-xiaoguangrong@tencent.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Currently, it includes:
pages: amount of pages compressed and transferred to the target VM
busy: amount of count that no free thread to compress data
busy-rate: rate of thread busy
compressed-size: amount of bytes after compression
compression-rate: rate of compressed size
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180906070101.27280-3-xiaoguangrong@tencent.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

flush_compressed_data() needs to wait all compression threads to
finish their work, after that all threads are free until the
migration feeds new request to them, reducing its call can improve
the throughput and use CPU resource more effectively

We do not need to flush all threads at the end of iteration, the
data can be kept locally until the memory block is changed or
memory migration starts over in that case we will meet a dirtied
page which may still exists in compression threads's ring
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Message-Id: <20180906070101.27280-2-xiaoguangrong@tencent.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

ram_find_and_save_block() can return negative if any error hanppens,
however, it is completely ignored in current code
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Message-Id: <20180903092644.25812-5-xiaoguangrong@tencent.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

As Peter pointed out:
| - xbzrle_counters.cache_miss is done in save_xbzrle_page(), so it's
|   per-guest-page granularity
|
| - RAMState.iterations is done for each ram_find_and_save_block(), so
|   it's per-host-page granularity
|
| An example is that when we migrate a 2M huge page in the guest, we
| will only increase the RAMState.iterations by 1 (since
| ram_find_and_save_block() will be called once), but we might increase
| xbzrle_counters.cache_miss for 2M/4K=512 times (we'll call
| save_xbzrle_page() that many times) if all the pages got cache miss.
| Then IMHO the cache miss rate will be 512/1=51200% (while it should
| actually be just 100% cache miss).

And he also suggested as xbzrle_counters.cache_miss_rate is the only
user of rs->iterations we can adapt it to count target guest page
numbers

After that, rename 'iterations' to 'target_page_count' to better reflect
its meaning
Suggested-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180903092644.25812-3-xiaoguangrong@tencent.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

The generated qapi_event_send_FOO() take an Error ** argument.  They
can't actually fail, because all they do with the argument is passing it
to functions that can't fail: the QObject output visitor, and the
@qmp_emit callback, which is either monitor_qapi_event_queue() or
event_test_emit().

Drop the argument, and pass &error_abort to the QObject output visitor
and @qmp_emit instead.
Suggested-by: NEric Blake <eblake@redhat.com>
Suggested-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180815133747.25032-4-peterx@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
[Commit message rewritten, update to qapi-code-gen.txt corrected]
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

Try to hold src_page_req_mutex only if the queue is not
empty
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Detecting zero page is not a light work, moving it to the thread to
speed the main thread up, btw, handling ram_release_pages() for the
zero page is moved to the thread as well
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It is not used and cleans the code up a little
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It will be used by the compression threads
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

The compressed page is not normal page
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Instead of putting the main thread to sleep state to wait for
free compression thread, we can directly post it out as normal
page that reduces the latency and uses CPUs more efficiently

A parameter, compress-wait-thread, is introduced, it can be
enabled if the user really wants the old behavior
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

This patch implements bi-directional RDMA QIOChannel. Because different
threads may access RDMAQIOChannel currently, this patch use RCU to protect it.
Signed-off-by: NLidong Chen <lidongchen@tencent.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Currently, the default maximum CPU throttle for migration is
99(CPU_THROTTLE_PCT_MAX). This is too big and can make a remarkable
performance effect for the guest. We see a lot of packets latency
exceed 500ms when the CPU_THROTTLE_PCT_MAX reached. This patch set
adds a new max-cpu-throttle parameter to limit the CPU throttle.
Signed-off-by: NLi Qiang <liq3ea@gmail.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Because we need to make sure the pmem kind memory data is synced
after migration, we choose to call pmem_persist() when the migration
finish. This will make sure the data of pmem is safe and will not
lose if power is off.
Signed-off-by: NJunyan He <junyan.he@intel.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

The nvdimm kind memory does not support post copy now.
We disable post copy if we have nvdimm memory and print some
log hint to user.
Signed-off-by: NJunyan He <junyan.he@intel.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

We shouldn't update the received bitmap if we're the source VM.  This
fixes a breakage when release-ram is enabled on postcopy.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180723123305.24792-2-peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

I would guess it won't happen normally, but this should ease Coverity.

>>>     CID 1394385:  Integer handling issues  (OVERFLOW_BEFORE_WIDEN)
>>>     Potentially overflowing expression "pages->used * 8192U" with type "unsigned int" (32 bits, unsigned) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "uint64_t" (64 bits, unsigned).
854         transferred = pages->used * TARGET_PAGE_SIZE + p->packet_len;

Fixes: CID 1394385
CC: Juan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180720034713.11711-1-peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

The calculation on size of received bitmap is incorrect for postcopy
recovery.  Here we wanted to let the size to cover all the valid bits in
the bitmap, we should use DIV_ROUND_UP() instead of a division.

For example, a RAMBlock with size=4K (which contains only one single 4K
page) will have nbits=1, then nbits/8=0, then the real bitmap won't be
sent to source at all.
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180710091902.28780-4-peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Firstly, renaming the old matching_page_sizes variable to
matches_target_page_size, which suites more to what it did (it only
checks against target page size rather than multiple page sizes).
Meanwhile, simplify the check logic a bit, and enhance the comments.
Should have no functional change.
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180710091902.28780-2-peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Move the call to migration_incoming_process() out of multifd code.  It's
a bit strange that we can migration generic calls in multifd code.
Instead, let multifd_recv_new_channel() return a boolean showing whether
it's ready to continue the incoming migration.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180627132246.5576-3-peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Not needed. Don't expose last_ram_page().
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20180620202736.21399-1-david@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

We have to flush() the QEMUFile because now we sent really few data
through that channel.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

We know quit with shutdwon in the QIO.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
--
Add comment
Use shutdown() instead of unref()

We have three conditions here:
- channel fails -> error
- we have to quit: we close the channel and reads fails
- normal read that success, we are in bussiness

So forget the complications of waiting in a semaphore.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

The function still don't use multifd, but we have simplified
ram_save_page, xbzrle and RDMA stuff is gone.  We have added a new
counter.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--
Add last_page parameter
Add commets for done and address
Remove multifd field, it is the same than normal pages
Merge next patch, now we send multiple pages at a time
Remove counter for multifd pages, it is identical to normal pages
Use iovec's instead of creating the equivalent.
Clear memory used by pages (dave)
Use g_new0(danp)
define MULTIFD_CONTINUE
now pages member is a pointer
Fix off-by-one in number of pages in one packet
Remove RAM_SAVE_FLAG_MULTIFD_PAGE
s/multifd_pages_t/MultiFDPages_t/
add comment explaining what it means

We synchronize all threads each RAM_SAVE_FLAG_EOS.  Bitmap
synchronizations don't happen inside a  ram section, so we are safe
about two channels trying to overwrite the same memory.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--
seq needs to be atomic now, will also be accessed from main thread.
Fix the if (true || ...) leftover
We are back to non-atomics

Once there add tracepoints.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Either for quit, sync or packet, we first wake them.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

We want to know how many pages/packets each channel has sent.  Add
counters for those.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--
sort trace-events (dave)

We still don't put anything there.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--
fix magic (dave)
check offset/ramblock  (dave)
s/seq/packet_num/ and make it 64bit

We only create/destry the page list here.  We will use it later.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

expected_downtime value is not accurate with dirty_pages_rate * page_size,
using ram_bytes_remaining() would yeild it resonable.

consider to read the remaining ram just after having updated the dirty
pages count later migration_bitmap_sync_range() in migration_bitmap_sync()
and reuse the `remaining` field in ram_counters to hold ram_bytes_remaining()
for calculating expected_downtime.
Reported-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NBalamuruhan S <bala24@linux.vnet.ibm.com>
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Message-Id: <20180612085009.17594-2-bala24@linux.vnet.ibm.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Use the 'urgent request' mechanism added in the previous patch
for entries added to the postcopy request queue for RAM.  Ignore
the rate limiting while we have requests.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20180613102642.23995-4-dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

It is used to slightly clean the code up, no logic is changed
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180604095520.8563-5-xiaoguangrong@tencent.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Sync up xbzrle_cache_miss_prev only after migration iteration goes
forward
Signed-off-by: NXiao Guangrong <xiaoguangrong@tencent.com>
Message-Id: <20180604095520.8563-4-xiaoguangrong@tencent.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>