migration: Remove non-multifd compression

The 'compress' migration capability enables the old compression code
which has shown issues over the years and is thought to be less stable
and tested than the more recent multifd-based compression. The old
compression code has been deprecated in 8.2 and now is time to remove
it.

Deprecation commit 864128df46 ("migration: Deprecate old compression
method").

Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>

1 files changed, 0 insertions, 564 deletions

diff --git a/migration/ram-compress.c b/migration/ram-compress.c
deleted file mode 100644
index fa4388f6a6..0000000000
--- a/migration/ram-compress.c
+++ /dev/null
@@ -1,564 +0,0 @@
-/*
- * QEMU System Emulator
- *
- * Copyright (c) 2003-2008 Fabrice Bellard
- * Copyright (c) 2011-2015 Red Hat Inc
- *
- * Authors:
- *  Juan Quintela <quintela@redhat.com>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include "qemu/osdep.h"
-#include "qemu/cutils.h"
-
-#include "ram-compress.h"
-
-#include "qemu/error-report.h"
-#include "qemu/stats64.h"
-#include "migration.h"
-#include "options.h"
-#include "io/channel-null.h"
-#include "exec/target_page.h"
-#include "exec/ramblock.h"
-#include "ram.h"
-#include "migration-stats.h"
-
-static struct {
-    int64_t pages;
-    int64_t busy;
-    double busy_rate;
-    int64_t compressed_size;
-    double compression_rate;
-    /* compression statistics since the beginning of the period */
-    /* amount of count that no free thread to compress data */
-    uint64_t compress_thread_busy_prev;
-    /* amount bytes after compression */
-    uint64_t compressed_size_prev;
-    /* amount of compressed pages */
-    uint64_t compress_pages_prev;
-} compression_counters;
-
-static CompressParam *comp_param;
-static QemuThread *compress_threads;
-/* comp_done_cond is used to wake up the migration thread when
- * one of the compression threads has finished the compression.
- * comp_done_lock is used to co-work with comp_done_cond.
- */
-static QemuMutex comp_done_lock;
-static QemuCond comp_done_cond;
-
-struct DecompressParam {
-    bool done;
-    bool quit;
-    QemuMutex mutex;
-    QemuCond cond;
-    void *des;
-    uint8_t *compbuf;
-    int len;
-    z_stream stream;
-};
-typedef struct DecompressParam DecompressParam;
-
-static QEMUFile *decomp_file;
-static DecompressParam *decomp_param;
-static QemuThread *decompress_threads;
-static QemuMutex decomp_done_lock;
-static QemuCond decomp_done_cond;
-
-static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
-                                           RAMBlock *block, ram_addr_t offset,
-                                           uint8_t *source_buf);
-
-static void *do_data_compress(void *opaque)
-{
-    CompressParam *param = opaque;
-    RAMBlock *block;
-    ram_addr_t offset;
-    CompressResult result;
-
-    qemu_mutex_lock(&param->mutex);
-    while (!param->quit) {
-        if (param->trigger) {
-            block = param->block;
-            offset = param->offset;
-            param->trigger = false;
-            qemu_mutex_unlock(&param->mutex);
-
-            result = do_compress_ram_page(param->file, &param->stream,
-                                          block, offset, param->originbuf);
-
-            qemu_mutex_lock(&comp_done_lock);
-            param->done = true;
-            param->result = result;
-            qemu_cond_signal(&comp_done_cond);
-            qemu_mutex_unlock(&comp_done_lock);
-
-            qemu_mutex_lock(&param->mutex);
-        } else {
-            qemu_cond_wait(&param->cond, &param->mutex);
-        }
-    }
-    qemu_mutex_unlock(&param->mutex);
-
-    return NULL;
-}
-
-void compress_threads_save_cleanup(void)
-{
-    int i, thread_count;
-
-    if (!migrate_compress() || !comp_param) {
-        return;
-    }
-
-    thread_count = migrate_compress_threads();
-    for (i = 0; i < thread_count; i++) {
-        /*
-         * we use it as a indicator which shows if the thread is
-         * properly init'd or not
-         */
-        if (!comp_param[i].file) {
-            break;
-        }
-
-        qemu_mutex_lock(&comp_param[i].mutex);
-        comp_param[i].quit = true;
-        qemu_cond_signal(&comp_param[i].cond);
-        qemu_mutex_unlock(&comp_param[i].mutex);
-
-        qemu_thread_join(compress_threads + i);
-        qemu_mutex_destroy(&comp_param[i].mutex);
-        qemu_cond_destroy(&comp_param[i].cond);
-        deflateEnd(&comp_param[i].stream);
-        g_free(comp_param[i].originbuf);
-        qemu_fclose(comp_param[i].file);
-        comp_param[i].file = NULL;
-    }
-    qemu_mutex_destroy(&comp_done_lock);
-    qemu_cond_destroy(&comp_done_cond);
-    g_free(compress_threads);
-    g_free(comp_param);
-    compress_threads = NULL;
-    comp_param = NULL;
-}
-
-int compress_threads_save_setup(void)
-{
-    int i, thread_count;
-
-    if (!migrate_compress()) {
-        return 0;
-    }
-    thread_count = migrate_compress_threads();
-    compress_threads = g_new0(QemuThread, thread_count);
-    comp_param = g_new0(CompressParam, thread_count);
-    qemu_cond_init(&comp_done_cond);
-    qemu_mutex_init(&comp_done_lock);
-    for (i = 0; i < thread_count; i++) {
-        comp_param[i].originbuf = g_try_malloc(qemu_target_page_size());
-        if (!comp_param[i].originbuf) {
-            goto exit;
-        }
-
-        if (deflateInit(&comp_param[i].stream,
-                        migrate_compress_level()) != Z_OK) {
-            g_free(comp_param[i].originbuf);
-            goto exit;
-        }
-
-        /* comp_param[i].file is just used as a dummy buffer to save data,
-         * set its ops to empty.
-         */
-        comp_param[i].file = qemu_file_new_output(
-            QIO_CHANNEL(qio_channel_null_new()));
-        comp_param[i].done = true;
-        comp_param[i].quit = false;
-        qemu_mutex_init(&comp_param[i].mutex);
-        qemu_cond_init(&comp_param[i].cond);
-        qemu_thread_create(compress_threads + i, "compress",
-                           do_data_compress, comp_param + i,
-                           QEMU_THREAD_JOINABLE);
-    }
-    return 0;
-
-exit:
-    compress_threads_save_cleanup();
-    return -1;
-}
-
-static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
-                                           RAMBlock *block, ram_addr_t offset,
-                                           uint8_t *source_buf)
-{
-    uint8_t *p = block->host + offset;
-    size_t page_size = qemu_target_page_size();
-    int ret;
-
-    assert(qemu_file_buffer_empty(f));
-
-    if (buffer_is_zero(p, page_size)) {
-        return RES_ZEROPAGE;
-    }
-
-    /*
-     * copy it to a internal buffer to avoid it being modified by VM
-     * so that we can catch up the error during compression and
-     * decompression
-     */
-    memcpy(source_buf, p, page_size);
-    ret = qemu_put_compression_data(f, stream, source_buf, page_size);
-    if (ret < 0) {
-        qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
-        error_report("compressed data failed!");
-        qemu_fflush(f);
-        return RES_NONE;
-    }
-    return RES_COMPRESS;
-}
-
-static inline void compress_reset_result(CompressParam *param)
-{
-    param->result = RES_NONE;
-    param->block = NULL;
-    param->offset = 0;
-}
-
-void compress_flush_data(void)
-{
-    int thread_count = migrate_compress_threads();
-
-    if (!migrate_compress()) {
-        return;
-    }
-
-    qemu_mutex_lock(&comp_done_lock);
-    for (int i = 0; i < thread_count; i++) {
-        while (!comp_param[i].done) {
-            qemu_cond_wait(&comp_done_cond, &comp_done_lock);
-        }
-    }
-    qemu_mutex_unlock(&comp_done_lock);
-
-    for (int i = 0; i < thread_count; i++) {
-        qemu_mutex_lock(&comp_param[i].mutex);
-        if (!comp_param[i].quit) {
-            CompressParam *param = &comp_param[i];
-            compress_send_queued_data(param);
-            assert(qemu_file_buffer_empty(param->file));
-            compress_reset_result(param);
-        }
-        qemu_mutex_unlock(&comp_param[i].mutex);
-    }
-}
-
-static inline void set_compress_params(CompressParam *param, RAMBlock *block,
-                                       ram_addr_t offset)
-{
-    param->block = block;
-    param->offset = offset;
-    param->trigger = true;
-}
-
-/*
- * Return true when it compress a page
- */
-bool compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset,
-                                     int (send_queued_data(CompressParam *)))
-{
-    int thread_count;
-    bool wait = migrate_compress_wait_thread();
-
-    thread_count = migrate_compress_threads();
-    qemu_mutex_lock(&comp_done_lock);
-
-    while (true) {
-        for (int i = 0; i < thread_count; i++) {
-            if (comp_param[i].done) {
-                CompressParam *param = &comp_param[i];
-                qemu_mutex_lock(&param->mutex);
-                param->done = false;
-                send_queued_data(param);
-                assert(qemu_file_buffer_empty(param->file));
-                compress_reset_result(param);
-                set_compress_params(param, block, offset);
-
-                qemu_cond_signal(&param->cond);
-                qemu_mutex_unlock(&param->mutex);
-                qemu_mutex_unlock(&comp_done_lock);
-                return true;
-            }
-        }
-        if (!wait) {
-            qemu_mutex_unlock(&comp_done_lock);
-            compression_counters.busy++;
-            return false;
-        }
-        /*
-         * wait for a free thread if the user specifies
-         * 'compress-wait-thread', otherwise we will post the page out
-         * in the main thread as normal page.
-         */
-        qemu_cond_wait(&comp_done_cond, &comp_done_lock);
-    }
-}
-
-/* return the size after decompression, or negative value on error */
-static int
-qemu_uncompress_data(z_stream *stream, uint8_t *dest, size_t dest_len,
-                     const uint8_t *source, size_t source_len)
-{
-    int err;
-
-    err = inflateReset(stream);
-    if (err != Z_OK) {
-        return -1;
-    }
-
-    stream->avail_in = source_len;
-    stream->next_in = (uint8_t *)source;
-    stream->avail_out = dest_len;
-    stream->next_out = dest;
-
-    err = inflate(stream, Z_NO_FLUSH);
-    if (err != Z_STREAM_END) {
-        return -1;
-    }
-
-    return stream->total_out;
-}
-
-static void *do_data_decompress(void *opaque)
-{
-    DecompressParam *param = opaque;
-    unsigned long pagesize;
-    uint8_t *des;
-    int len, ret;
-
-    qemu_mutex_lock(&param->mutex);
-    while (!param->quit) {
-        if (param->des) {
-            des = param->des;
-            len = param->len;
-            param->des = 0;
-            qemu_mutex_unlock(&param->mutex);
-
-            pagesize = qemu_target_page_size();
-
-            ret = qemu_uncompress_data(&param->stream, des, pagesize,
-                                       param->compbuf, len);
-            if (ret < 0 && migrate_get_current()->decompress_error_check) {
-                error_report("decompress data failed");
-                qemu_file_set_error(decomp_file, ret);
-            }
-
-            qemu_mutex_lock(&decomp_done_lock);
-            param->done = true;
-            qemu_cond_signal(&decomp_done_cond);
-            qemu_mutex_unlock(&decomp_done_lock);
-
-            qemu_mutex_lock(&param->mutex);
-        } else {
-            qemu_cond_wait(&param->cond, &param->mutex);
-        }
-    }
-    qemu_mutex_unlock(&param->mutex);
-
-    return NULL;
-}
-
-int wait_for_decompress_done(void)
-{
-    if (!migrate_compress()) {
-        return 0;
-    }
-
-    int thread_count = migrate_decompress_threads();
-    qemu_mutex_lock(&decomp_done_lock);
-    for (int i = 0; i < thread_count; i++) {
-        while (!decomp_param[i].done) {
-            qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
-        }
-    }
-    qemu_mutex_unlock(&decomp_done_lock);
-    return qemu_file_get_error(decomp_file);
-}
-
-void compress_threads_load_cleanup(void)
-{
-    int i, thread_count;
-
-    if (!migrate_compress()) {
-        return;
-    }
-    thread_count = migrate_decompress_threads();
-    for (i = 0; i < thread_count; i++) {
-        /*
-         * we use it as a indicator which shows if the thread is
-         * properly init'd or not
-         */
-        if (!decomp_param[i].compbuf) {
-            break;
-        }
-
-        qemu_mutex_lock(&decomp_param[i].mutex);
-        decomp_param[i].quit = true;
-        qemu_cond_signal(&decomp_param[i].cond);
-        qemu_mutex_unlock(&decomp_param[i].mutex);
-    }
-    for (i = 0; i < thread_count; i++) {
-        if (!decomp_param[i].compbuf) {
-            break;
-        }
-
-        qemu_thread_join(decompress_threads + i);
-        qemu_mutex_destroy(&decomp_param[i].mutex);
-        qemu_cond_destroy(&decomp_param[i].cond);
-        inflateEnd(&decomp_param[i].stream);
-        g_free(decomp_param[i].compbuf);
-        decomp_param[i].compbuf = NULL;
-    }
-    g_free(decompress_threads);
-    g_free(decomp_param);
-    decompress_threads = NULL;
-    decomp_param = NULL;
-    decomp_file = NULL;
-}
-
-int compress_threads_load_setup(QEMUFile *f)
-{
-    int i, thread_count;
-
-    if (!migrate_compress()) {
-        return 0;
-    }
-
-    /*
-     * set compression_counters memory to zero for a new migration
-     */
-    memset(&compression_counters, 0, sizeof(compression_counters));
-
-    thread_count = migrate_decompress_threads();
-    decompress_threads = g_new0(QemuThread, thread_count);
-    decomp_param = g_new0(DecompressParam, thread_count);
-    qemu_mutex_init(&decomp_done_lock);
-    qemu_cond_init(&decomp_done_cond);
-    decomp_file = f;
-    for (i = 0; i < thread_count; i++) {
-        if (inflateInit(&decomp_param[i].stream) != Z_OK) {
-            goto exit;
-        }
-
-        size_t compbuf_size = compressBound(qemu_target_page_size());
-        decomp_param[i].compbuf = g_malloc0(compbuf_size);
-        qemu_mutex_init(&decomp_param[i].mutex);
-        qemu_cond_init(&decomp_param[i].cond);
-        decomp_param[i].done = true;
-        decomp_param[i].quit = false;
-        qemu_thread_create(decompress_threads + i, "decompress",
-                           do_data_decompress, decomp_param + i,
-                           QEMU_THREAD_JOINABLE);
-    }
-    return 0;
-exit:
-    compress_threads_load_cleanup();
-    return -1;
-}
-
-void decompress_data_with_multi_threads(QEMUFile *f, void *host, int len)
-{
-    int thread_count = migrate_decompress_threads();
-    QEMU_LOCK_GUARD(&decomp_done_lock);
-    while (true) {
-        for (int i = 0; i < thread_count; i++) {
-            if (decomp_param[i].done) {
-                decomp_param[i].done = false;
-                qemu_mutex_lock(&decomp_param[i].mutex);
-                qemu_get_buffer(f, decomp_param[i].compbuf, len);
-                decomp_param[i].des = host;
-                decomp_param[i].len = len;
-                qemu_cond_signal(&decomp_param[i].cond);
-                qemu_mutex_unlock(&decomp_param[i].mutex);
-                return;
-            }
-        }
-        qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
-    }
-}
-
-void populate_compress(MigrationInfo *info)
-{
-    if (!migrate_compress()) {
-        return;
-    }
-    info->compression = g_malloc0(sizeof(*info->compression));
-    info->compression->pages = compression_counters.pages;
-    info->compression->busy = compression_counters.busy;
-    info->compression->busy_rate = compression_counters.busy_rate;
-    info->compression->compressed_size = compression_counters.compressed_size;
-    info->compression->compression_rate = compression_counters.compression_rate;
-}
-
-uint64_t compress_ram_pages(void)
-{
-    return compression_counters.pages;
-}
-
-void update_compress_thread_counts(const CompressParam *param, int bytes_xmit)
-{
-    ram_transferred_add(bytes_xmit);
-
-    if (param->result == RES_ZEROPAGE) {
-        stat64_add(&mig_stats.zero_pages, 1);
-        return;
-    }
-
-    /* 8 means a header with RAM_SAVE_FLAG_CONTINUE. */
-    compression_counters.compressed_size += bytes_xmit - 8;
-    compression_counters.pages++;
-}
-
-void compress_update_rates(uint64_t page_count)
-{
-    if (!migrate_compress()) {
-        return;
-    }
-    compression_counters.busy_rate = (double)(compression_counters.busy -
-            compression_counters.compress_thread_busy_prev) / page_count;
-    compression_counters.compress_thread_busy_prev =
-            compression_counters.busy;
-
-    double compressed_size = compression_counters.compressed_size -
-        compression_counters.compressed_size_prev;
-    if (compressed_size) {
-        double uncompressed_size = (compression_counters.pages -
-                                    compression_counters.compress_pages_prev) *
-            qemu_target_page_size();
-
-        /* Compression-Ratio = Uncompressed-size / Compressed-size */
-        compression_counters.compression_rate =
-            uncompressed_size / compressed_size;
-
-        compression_counters.compress_pages_prev =
-            compression_counters.pages;
-        compression_counters.compressed_size_prev =
-            compression_counters.compressed_size;
-    }
-}