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2022-07-20migration: remove unreachable code after reading dataDaniel P. Berrangé1-3/+1
The code calls qio_channel_read() in a loop when it reports QIO_CHANNEL_ERR_BLOCK. This code is reported when errno==EAGAIN. As such the later block of code will always hit the 'errno != EAGAIN' condition, making the final 'else' unreachable. Fixes: Coverity CID 1490203 Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20220627135318.156121-1-berrange@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20migration: Postcopy recover with preempt enabledPeter Xu1-0/+27
To allow postcopy recovery, the ram fast load (preempt-only) dest QEMU thread needs similar handling on fault tolerance. When ram_load_postcopy() fails, instead of stopping the thread it halts with a semaphore, preparing to be kicked again when recovery is detected. A mutex is introduced to make sure there's no concurrent operation upon the socket. To make it simple, the fast ram load thread will take the mutex during its whole procedure, and only release it if it's paused. The fast-path socket will be properly released by the main loading thread safely when there's network failures during postcopy with that mutex held. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20220707185506.27257-1-peterx@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-23migration: remove the QEMUFileOps abstractionDaniel P. Berrangé1-12/+8
Now that all QEMUFile callbacks are removed, the entire concept can be deleted. 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>
2022-06-23migration: remove the QEMUFileOps 'get_return_path' callbackDaniel P. Berrangé1-12/+10
This directly implements the get_return_path logic using QIOChannel APIs. 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>
2022-06-23migration: remove the QEMUFileOps 'writev_buffer' callbackDaniel P. Berrangé1-16/+8
This directly implements the writev_buffer logic using QIOChannel APIs. 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>
2022-06-23migration: remove the QEMUFileOps 'get_buffer' callbackDaniel P. Berrangé1-2/+16
This directly implements the get_buffer logic using QIOChannel APIs. 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: Fixup len = *-*EIO as spotted by Peter Xu
2022-06-22migration: remove the QEMUFileOps 'close' callbackDaniel P. Berrangé1-6/+6
This directly implements the close logic using QIOChannel APIs. 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>
2022-06-22migration: remove the QEMUFileOps 'set_blocking' callbackDaniel P. Berrangé1-3/+1
This directly implements the set_blocking logic using QIOChannel APIs. 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>
2022-06-22migration: remove the QEMUFileOps 'shut_down' callbackDaniel P. Berrangé1-3/+10
This directly implements the shutdown logic using QIOChannel APIs. 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>
2022-06-22migration: introduce new constructors for QEMUFileDaniel P. Berrangé1-2/+16
Prepare for the elimination of QEMUFileOps by introducing a pair of new constructors. This lets us distinguish between an input and output file object explicitly rather than via the existance of specific callbacks. 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>
2022-06-22migration: hardcode assumption that QEMUFile is backed with QIOChannelDaniel P. Berrangé1-18/+17
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
2022-06-22migration: stop passing 'opaque' parameter to QEMUFile hooksDaniel P. Berrangé1-4/+4
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>
2022-06-22migration: rename qemu_file_update_transfer to qemu_file_acct_rate_limitDaniel P. Berrangé1-1/+1
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>
2022-06-22migration: rename qemu_update_position to qemu_file_credit_transferDaniel P. Berrangé1-2/+2
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>
2022-06-22migration: rename qemu_ftell to qemu_file_total_transferredDaniel P. Berrangé1-2/+2
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
2022-06-22migration: rename 'pos' field in QEMUFile to 'bytes_processed'Daniel P. Berrangé1-10/+11
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
2022-06-22migration: rename rate limiting fields in QEMUFileDaniel P. Berrangé1-11/+19
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>
2022-02-21include: Move qemu_madvise() and related #defines to new qemu/madvise.hPeter Maydell1-0/+1
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
2021-07-26migration: Teach QEMUFile to be QIOChannel-awarePeter Xu1-1/+16
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>
2021-07-05migration: fix the memory overwriting risk in add_to_iovecFeng Lin1-0/+5
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'
2021-02-08migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()Wainer dos Santos Moschetta1-1/+1
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>
2020-06-26osdep: Make MIN/MAX evaluate arguments only onceEric Blake1-1/+1
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>
2020-01-29migration/compress: compress QEMUFile is not writableWei Yang1-13/+3
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>
2020-01-29qemu-file: Don't do IO after shutdownJuan Quintela1-1/+21
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>
2019-09-12migration/qemu-file: fix potential buf waste for extra buf_index adjustmentWei Yang1-17/+26
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>
2019-09-12migration/qemu-file: remove check on writev_buffer in qemu_put_compression_dataWei Yang1-3/+1
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>
2019-09-12qemu-file: Rework old qemu_fflush commentDr. David Alan Gilbert1-3/+2
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>
2019-08-14migration: add qemu_file_update_transfer interfaceIvan Ren1-0/+5
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>
2019-08-14migration: Add error_desc for file channel errorsYury Kotov1-12/+51
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>
2019-06-12Include qemu-common.h exactly where neededMarkus Armbruster1-1/+0
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]
2018-08-22migration: disable RDMA WRITE after postcopy startedLidong Chen1-2/+6
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>
2018-04-25migration: detect compression and decompression errorsXiao Guangrong1-2/+2
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>
2018-04-25migration: stop compression to allocate and free memory frequentlyXiao Guangrong1-7/+32
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>
2018-03-23migration: Fix rate limiting issue on RDMA migrationLidong Chen1-1/+1
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>
2018-03-13migration/qemu-file: add qemu_put_counted_string()Vladimir Sementsov-Ogievskiy1-0/+13
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
2017-06-14migration: Remove unneeded includesJuan Quintela1-2/+0
Signed-off-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
2017-06-13migration: Move migration.h to migration/Juan Quintela1-1/+1
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>
2017-06-01migration: Split qemu-file.hJuan Quintela1-1/+1
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>
2017-02-13add 'release-ram' migrate capabilityPavel Butsykin1-7/+52
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!'
2016-08-11migration: fix live migration failure with compressionLiang Li1-0/+1
Because of commit 11808bb0c422, 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>
2016-06-17qemu-file: Fix qemu_put_compression_data flawLiang Li1-2/+21
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>
2016-05-26migration: remove qemu_get_fd method from QEMUFileDaniel P. Berrange1-14/+0
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>
2016-05-26migration: remove support for non-iovec based write handlersDaniel P. Berrange1-28/+8
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>
2016-05-26migration: move definition of struct QEMUFile back into qemu-file.cDaniel P. Berrange1-1/+23
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>
2016-05-26migration: introduce set_blocking function in QEMUFileOpsDaniel P. Berrange1-3/+7
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>
2016-05-26migration: split migration hooks out of QEMUFileOpsDaniel P. Berrange1-9/+15
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>
2016-05-26migration: ensure qemu_fflush() always writes full data amountDaniel P. Berrange1-4/+12
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>
2016-01-29migration: Clean up includesPeter Maydell1-0/+1
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
2015-11-10Return path: Open a return path on QEMUFile for socketsDr. David Alan Gilbert1-0/+12
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>
2015-11-10Add wrapper for setting blocking status on a QEMUFileDr. David Alan Gilbert1-0/+15
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>