Merge tag 'compression-code-pull-request' of https://gitlab.com/juan.…

…quintela/qemu into staging

Migration PULL request (20230508 edition, take 2)

Hi

This is just the compression bits of the Migration PULL request for
20230428.  Only change is that we don't run the compression tests by
default.

The problem already exist with compression code.  The test just show
that it don't work.

- Add migration tests for (old) compress migration code (lukas)
- Make compression code independent of ram.c (lukas)
- Move compression code into ram-compress.c (lukas)

Please apply, Juan.

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# gpg: Signature made Mon 08 May 2023 07:51:56 PM BST
# gpg:                using RSA key 1899FF8EDEBF58CCEE034B82F487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>" [undefined]
# gpg:                 aka "Juan Quintela <quintela@trasno.org>" [undefined]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* tag 'compression-code-pull-request' of https://gitlab.com/juan.quintela/qemu:
  migration: Initialize and cleanup decompression in migration.c
  ram-compress.c: Make target independent
  ram compress: Assert that the file buffer matches the result
  ram.c: Move core decompression code into its own file
  ram.c: Move core compression code into its own file
  ram.c: Remove last ram.c dependency from the core compress code
  ram.c: Call update_compress_thread_counts from compress_send_queued_data
  ram.c: Do not call save_page_header() from compress threads
  ram.c: Reset result after sending queued data
  ram.c: Dont change param->block in the compress thread
  ram.c: Let the compress threads return a CompressResult enum
  qtest/migration-test.c: Add postcopy tests with compress enabled
  qtest/migration-test.c: Add tests with compress enabled

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

migration/meson.build

@@ -23,6 +23,8 @@ softmmu_ss.add(files(
   'migration.c',
   'multifd.c',
   'multifd-zlib.c',
+  'multifd-zlib.c',
+  'ram-compress.c',
   'options.c',
   'postcopy-ram.c',
   'savevm.c',
@@ -38,4 +40,6 @@ endif
 softmmu_ss.add(when: zstd, if_true: files('multifd-zstd.c'))
 
 specific_ss.add(when: 'CONFIG_SOFTMMU',
-                if_true: files('dirtyrate.c', 'ram.c', 'target.c'))
+                if_true: files('dirtyrate.c',
+                               'ram.c',
+                               'target.c'))

migration/migration.c

@@ -26,6 +26,7 @@
 #include "sysemu/cpu-throttle.h"
 #include "rdma.h"
 #include "ram.h"
+#include "ram-compress.h"
 #include "migration/global_state.h"
 #include "migration/misc.h"
 #include "migration.h"
@@ -228,6 +229,7 @@ void migration_incoming_state_destroy(void)
     struct MigrationIncomingState *mis = migration_incoming_get_current();
 
     multifd_load_cleanup();
+    compress_threads_load_cleanup();
 
     if (mis->to_src_file) {
         /* Tell source that we are done */
@@ -500,6 +502,12 @@ process_incoming_migration_co(void *opaque)
     Error *local_err = NULL;
 
     assert(mis->from_src_file);
+
+    if (compress_threads_load_setup(mis->from_src_file)) {
+        error_report("Failed to setup decompress threads");
+        goto fail;
+    }
+
     mis->migration_incoming_co = qemu_coroutine_self();
     mis->largest_page_size = qemu_ram_pagesize_largest();
     postcopy_state_set(POSTCOPY_INCOMING_NONE);
@@ -565,6 +573,7 @@ process_incoming_migration_co(void *opaque)
     qemu_fclose(mis->from_src_file);
 
     multifd_load_cleanup();
+    compress_threads_load_cleanup();
 
     exit(EXIT_FAILURE);
 }

migration/qemu-file.c

@@ -870,6 +870,17 @@ int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src)
     return len;
 }
 
+/*
+ * Check if the writable buffer is empty
+ */
+
+bool qemu_file_buffer_empty(QEMUFile *file)
+{
+    assert(qemu_file_is_writable(file));
+
+    return !file->iovcnt;
+}
+
 /*
  * Get a string whose length is determined by a single preceding byte
  * A preallocated 256 byte buffer must be passed in.

migration/qemu-file.h

@@ -113,6 +113,7 @@ size_t coroutine_mixed_fn qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, s
 ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
                                   const uint8_t *p, size_t size);
 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
+bool qemu_file_buffer_empty(QEMUFile *file);
 
 /*
  * Note that you can only peek continuous bytes from where the current pointer