[PATCH 00/14] migration/ram.c: Refactor compress code

[PATCH 00/14] migration/ram.c: Refactor compress code

[Lukas Straub]

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This series refactors the ram compress code.

It first removes ram.c dependencies from the core compress code, then
moves it out to its own file. Finally, on the migration destination side
the initialisation and cleanup of compress threads is moved out of ram.c
to migration.c. This allows using COLO with compress enabled.

This series is based on the following series:
https://lore.kernel.org/qemu-devel/af76761aa6978071c5b8e9b872b697db465a5520.1680457631.git.lukasstraub2@web.de/T/#t

Lukas Straub (14):
  ram.c: Let the compress threads return a CompressResult enum
  ram.c: Dont change param->block in the compress thread
  ram.c: Reset result after sending queued data
  ram.c: Do not call save_page_header() from compress threads
  ram.c: Call update_compress_thread_counts from
    compress_send_queued_data
  ram.c: Remove last ram.c dependency from the core compress code
  ram.c: Introduce whitespace (squash with next patch)
  ram.c: Move core compression code into its own file
  ram.c: Remove whitespace (squash with previous patch)
  ram.c: Move core decompression code into its own file
  ram compress: Assert that the file buffer matches the result
  ram.c: Remove unused include after moving out code
  ram-compress.c: Make target independent
  migration: Initialize and cleanup decompression in migration.c

 migration/meson.build    |   5 +-
 migration/migration.c    |   9 +
 migration/qemu-file.c    |  11 +
 migration/qemu-file.h    |   1 +
 migration/ram-compress.c | 483 ++++++++++++++++++++++++++++++++++++++
 migration/ram-compress.h |  70 ++++++
 migration/ram.c          | 490 +++------------------------------------
 7 files changed, 615 insertions(+), 454 deletions(-)
 create mode 100644 migration/ram-compress.c
 create mode 100644 migration/ram-compress.h

--
2.30.2

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[PATCH 01/14] ram.c: Let the compress threads return a CompressResult enum

[Lukas Straub]

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This will be used in the next commits to move save_page_header()
out of compress code.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 9d1817ab7b..ca561e62bd 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -493,10 +493,17 @@ MigrationOps *migration_ops;

 CompressionStats compression_counters;

+enum CompressResult {
+    RES_NONE = 0,
+    RES_ZEROPAGE = 1,
+    RES_COMPRESS = 2
+};
+typedef enum CompressResult CompressResult;
+
 struct CompressParam {
     bool done;
     bool quit;
-    bool zero_page;
+    CompressResult result;
     QEMUFile *file;
     QemuMutex mutex;
     QemuCond cond;
@@ -538,8 +545,9 @@ static QemuCond decomp_done_cond;

 static int ram_save_host_page_urgent(PageSearchStatus *pss);

-static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
-                                 ram_addr_t offset, uint8_t *source_buf);
+static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
+                                           RAMBlock *block, ram_addr_t offset,
+                                           uint8_t *source_buf);

 /* NOTE: page is the PFN not real ram_addr_t. */
 static void pss_init(PageSearchStatus *pss, RAMBlock *rb, ram_addr_t page)
@@ -564,7 +572,7 @@ static void *do_data_compress(void *opaque)
     CompressParam *param = opaque;
     RAMBlock *block;
     ram_addr_t offset;
-    bool zero_page;
+    CompressResult result;

     qemu_mutex_lock(&param->mutex);
     while (!param->quit) {
@@ -574,12 +582,12 @@ static void *do_data_compress(void *opaque)
             param->block = NULL;
             qemu_mutex_unlock(&param->mutex);

-            zero_page = do_compress_ram_page(param->file, &param->stream,
-                                             block, offset, param->originbuf);
+            result = do_compress_ram_page(param->file, &param->stream,
+                                          block, offset, param->originbuf);

             qemu_mutex_lock(&comp_done_lock);
             param->done = true;
-            param->zero_page = zero_page;
+            param->result = result;
             qemu_cond_signal(&comp_done_cond);
             qemu_mutex_unlock(&comp_done_lock);

@@ -1463,8 +1471,9 @@ static int ram_save_multifd_page(QEMUFile *file, RAMBlock *block,
     return 1;
 }

-static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
-                                 ram_addr_t offset, uint8_t *source_buf)
+static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
+                                           RAMBlock *block, ram_addr_t offset,
+                                           uint8_t *source_buf)
 {
     RAMState *rs = ram_state;
     PageSearchStatus *pss = &rs->pss[RAM_CHANNEL_PRECOPY];
@@ -1472,7 +1481,7 @@ static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
     int ret;

     if (save_zero_page_to_file(pss, f, block, offset)) {
-        return true;
+        return RES_ZEROPAGE;
     }

     save_page_header(pss, f, block, offset | RAM_SAVE_FLAG_COMPRESS_PAGE);
@@ -1487,8 +1496,9 @@ static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
     if (ret < 0) {
         qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
         error_report("compressed data failed!");
+        return RES_NONE;
     }
-    return false;
+    return RES_COMPRESS;
 }

 static void
@@ -1496,7 +1506,7 @@ update_compress_thread_counts(const CompressParam *param, int bytes_xmit)
 {
     ram_transferred_add(bytes_xmit);

-    if (param->zero_page) {
+    if (param->result == RES_ZEROPAGE) {
         stat64_add(&ram_atomic_counters.duplicate, 1);
         return;
     }
--
2.30.2


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[PATCH 02/14] ram.c: Dont change param->block in the compress thread

[Lukas Straub]

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Instead introduce a extra parameter to trigger the compress thread.
Now, when the compress thread is done, we know what RAMBlock and
offset it did compress.

This will be used in the next commits to move save_page_header()
out of compress code.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index ca561e62bd..3c9fac086d 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -503,6 +503,7 @@ typedef enum CompressResult CompressResult;
 struct CompressParam {
     bool done;
     bool quit;
+    bool trigger;
     CompressResult result;
     QEMUFile *file;
     QemuMutex mutex;
@@ -576,10 +577,10 @@ static void *do_data_compress(void *opaque)

     qemu_mutex_lock(&param->mutex);
     while (!param->quit) {
-        if (param->block) {
+        if (param->trigger) {
             block = param->block;
             offset = param->offset;
-            param->block = NULL;
+            param->trigger = false;
             qemu_mutex_unlock(&param->mutex);

             result = do_compress_ram_page(param->file, &param->stream,
@@ -1556,6 +1557,7 @@ static inline void set_compress_params(CompressParam *param, RAMBlock *block,
 {
     param->block = block;
     param->offset = offset;
+    param->trigger = true;
 }

 static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset)
--
2.30.2


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[PATCH 03/14] ram.c: Reset result after sending queued data

[Lukas Straub]

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And take the param->mutex lock for the whole section to ensure
thread-safety.
Now, it is explicitly clear if there is no queued data to send.
Before, this was handled by param->file stream being empty and thus
qemu_put_qemu_file() not sending anything.

This will be used in the next commits to move save_page_header()
out of compress code.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 3c9fac086d..bef6292ef7 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1519,6 +1519,13 @@ update_compress_thread_counts(const CompressParam *param, int bytes_xmit)

 static bool save_page_use_compression(RAMState *rs);

+static inline void compress_reset_result(CompressParam *param)
+{
+    param->result = RES_NONE;
+    param->block = NULL;
+    param->offset = 0;
+}
+
 static void flush_compressed_data(RAMState *rs)
 {
     MigrationState *ms = migrate_get_current();
@@ -1540,13 +1547,16 @@ static void flush_compressed_data(RAMState *rs)
     for (idx = 0; idx < thread_count; idx++) {
         qemu_mutex_lock(&comp_param[idx].mutex);
         if (!comp_param[idx].quit) {
-            len = qemu_put_qemu_file(ms->to_dst_file, comp_param[idx].file);
+            CompressParam *param = &comp_param[idx];
+            len = qemu_put_qemu_file(ms->to_dst_file, param->file);
+            compress_reset_result(param);
+
             /*
              * it's safe to fetch zero_page without holding comp_done_lock
              * as there is no further request submitted to the thread,
              * i.e, the thread should be waiting for a request at this point.
              */
-            update_compress_thread_counts(&comp_param[idx], len);
+            update_compress_thread_counts(param, len);
         }
         qemu_mutex_unlock(&comp_param[idx].mutex);
     }
@@ -1571,15 +1581,17 @@ static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset)
 retry:
     for (idx = 0; idx < thread_count; idx++) {
         if (comp_param[idx].done) {
-            comp_param[idx].done = false;
-            bytes_xmit = qemu_put_qemu_file(ms->to_dst_file,
-                                            comp_param[idx].file);
-            qemu_mutex_lock(&comp_param[idx].mutex);
-            set_compress_params(&comp_param[idx], block, offset);
-            qemu_cond_signal(&comp_param[idx].cond);
-            qemu_mutex_unlock(&comp_param[idx].mutex);
+            CompressParam *param = &comp_param[idx];
+            qemu_mutex_lock(&param->mutex);
+            param->done = false;
+            bytes_xmit = qemu_put_qemu_file(ms->to_dst_file, param->file);
+            compress_reset_result(param);
+            set_compress_params(param, block, offset);
+
+            update_compress_thread_counts(param, bytes_xmit);
+            qemu_cond_signal(&param->cond);
+            qemu_mutex_unlock(&param->mutex);
             pages = 1;
-            update_compress_thread_counts(&comp_param[idx], bytes_xmit);
             break;
         }
     }
--
2.30.2


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[PATCH 04/14] ram.c: Do not call save_page_header() from compress threads

[Lukas Straub]

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save_page_header() accesses several global variables, so calling it
from multiple threads is pretty ugly.

Instead, call save_page_header() before writing out the compressed
data from the compress buffer to the migration stream.

This also makes the core compress code more independend from ram.c.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 44 +++++++++++++++++++++++++++++++++++---------
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index bef6292ef7..7ab008145b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1476,17 +1476,13 @@ static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
                                            RAMBlock *block, ram_addr_t offset,
                                            uint8_t *source_buf)
 {
-    RAMState *rs = ram_state;
-    PageSearchStatus *pss = &rs->pss[RAM_CHANNEL_PRECOPY];
     uint8_t *p = block->host + offset;
     int ret;

-    if (save_zero_page_to_file(pss, f, block, offset)) {
+    if (buffer_is_zero(p, TARGET_PAGE_SIZE)) {
         return RES_ZEROPAGE;
     }

-    save_page_header(pss, f, block, offset | RAM_SAVE_FLAG_COMPRESS_PAGE);
-
     /*
      * copy it to a internal buffer to avoid it being modified by VM
      * so that we can catch up the error during compression and
@@ -1526,9 +1522,40 @@ static inline void compress_reset_result(CompressParam *param)
     param->offset = 0;
 }

-static void flush_compressed_data(RAMState *rs)
+static int send_queued_data(CompressParam *param)
 {
+    PageSearchStatus *pss = &ram_state->pss[RAM_CHANNEL_PRECOPY];
     MigrationState *ms = migrate_get_current();
+    QEMUFile *file = ms->to_dst_file;
+    int len = 0;
+
+    RAMBlock *block = param->block;
+    ram_addr_t offset = param->offset;
+
+    if (param->result == RES_NONE) {
+        return 0;
+    }
+
+    assert(block == pss->last_sent_block);
+
+    if (param->result == RES_ZEROPAGE) {
+        len += save_page_header(pss, file, block, offset | RAM_SAVE_FLAG_ZERO);
+        qemu_put_byte(file, 0);
+        len += 1;
+        ram_release_page(block->idstr, offset);
+    } else if (param->result == RES_COMPRESS) {
+        len += save_page_header(pss, file, block,
+                                offset | RAM_SAVE_FLAG_COMPRESS_PAGE);
+        len += qemu_put_qemu_file(file, param->file);
+    } else {
+        abort();
+    }
+
+    return len;
+}
+
+static void flush_compressed_data(RAMState *rs)
+{
     int idx, len, thread_count;

     if (!save_page_use_compression(rs)) {
@@ -1548,7 +1575,7 @@ static void flush_compressed_data(RAMState *rs)
         qemu_mutex_lock(&comp_param[idx].mutex);
         if (!comp_param[idx].quit) {
             CompressParam *param = &comp_param[idx];
-            len = qemu_put_qemu_file(ms->to_dst_file, param->file);
+            len = send_queued_data(param);
             compress_reset_result(param);

             /*
@@ -1574,7 +1601,6 @@ static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset)
 {
     int idx, thread_count, bytes_xmit = -1, pages = -1;
     bool wait = migrate_compress_wait_thread();
-    MigrationState *ms = migrate_get_current();

     thread_count = migrate_compress_threads();
     qemu_mutex_lock(&comp_done_lock);
@@ -1584,7 +1610,7 @@ retry:
             CompressParam *param = &comp_param[idx];
             qemu_mutex_lock(&param->mutex);
             param->done = false;
-            bytes_xmit = qemu_put_qemu_file(ms->to_dst_file, param->file);
+            bytes_xmit = send_queued_data(param);
             compress_reset_result(param);
             set_compress_params(param, block, offset);

--
2.30.2


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[PATCH 05/14] ram.c: Call update_compress_thread_counts from compress_send_queued_data

[Lukas Straub]

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This makes the core compress code more independend from ram.c.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 7ab008145b..f55eb0e587 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1551,12 +1551,14 @@ static int send_queued_data(CompressParam *param)
         abort();
     }

+    update_compress_thread_counts(param, len);
+
     return len;
 }

 static void flush_compressed_data(RAMState *rs)
 {
-    int idx, len, thread_count;
+    int idx, thread_count;

     if (!save_page_use_compression(rs)) {
         return;
@@ -1575,15 +1577,8 @@ static void flush_compressed_data(RAMState *rs)
         qemu_mutex_lock(&comp_param[idx].mutex);
         if (!comp_param[idx].quit) {
             CompressParam *param = &comp_param[idx];
-            len = send_queued_data(param);
+            send_queued_data(param);
             compress_reset_result(param);
-
-            /*
-             * it's safe to fetch zero_page without holding comp_done_lock
-             * as there is no further request submitted to the thread,
-             * i.e, the thread should be waiting for a request at this point.
-             */
-            update_compress_thread_counts(param, len);
         }
         qemu_mutex_unlock(&comp_param[idx].mutex);
     }
@@ -1599,7 +1594,7 @@ static inline void set_compress_params(CompressParam *param, RAMBlock *block,

 static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset)
 {
-    int idx, thread_count, bytes_xmit = -1, pages = -1;
+    int idx, thread_count, pages = -1;
     bool wait = migrate_compress_wait_thread();

     thread_count = migrate_compress_threads();
@@ -1610,11 +1605,10 @@ retry:
             CompressParam *param = &comp_param[idx];
             qemu_mutex_lock(&param->mutex);
             param->done = false;
-            bytes_xmit = send_queued_data(param);
+            send_queued_data(param);
             compress_reset_result(param);
             set_compress_params(param, block, offset);

-            update_compress_thread_counts(param, bytes_xmit);
             qemu_cond_signal(&param->cond);
             qemu_mutex_unlock(&param->mutex);
             pages = 1;
--
2.30.2


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[PATCH 06/14] ram.c: Remove last ram.c dependency from the core compress code

[Lukas Straub]

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Make compression interfaces take send_queued_data() as an argument.
Remove save_page_use_compression() from flush_compressed_data().

This removes the last ram.c dependency from the core compress code.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index f55eb0e587..20428ccf42 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1556,13 +1556,10 @@ static int send_queued_data(CompressParam *param)
     return len;
 }

-static void flush_compressed_data(RAMState *rs)
+static void flush_compressed_data(int (send_queued_data(CompressParam *)))
 {
     int idx, thread_count;

-    if (!save_page_use_compression(rs)) {
-        return;
-    }
     thread_count = migrate_compress_threads();

     qemu_mutex_lock(&comp_done_lock);
@@ -1584,6 +1581,15 @@ static void flush_compressed_data(RAMState *rs)
     }
 }

+static void ram_flush_compressed_data(RAMState *rs)
+{
+    if (!save_page_use_compression(rs)) {
+        return;
+    }
+
+    flush_compressed_data(send_queued_data);
+}
+
 static inline void set_compress_params(CompressParam *param, RAMBlock *block,
                                        ram_addr_t offset)
 {
@@ -1592,7 +1598,8 @@ static inline void set_compress_params(CompressParam *param, RAMBlock *block,
     param->trigger = true;
 }

-static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset)
+static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset,
+                                int (send_queued_data(CompressParam *)))
 {
     int idx, thread_count, pages = -1;
     bool wait = migrate_compress_wait_thread();
@@ -1673,7 +1680,7 @@ static int find_dirty_block(RAMState *rs, PageSearchStatus *pss)
              * Also If xbzrle is on, stop using the data compression at this
              * point. In theory, xbzrle can do better than compression.
              */
-            flush_compressed_data(rs);
+            ram_flush_compressed_data(rs);

             /* Hit the end of the list */
             pss->block = QLIST_FIRST_RCU(&ram_list.blocks);
@@ -2363,11 +2370,11 @@ static bool save_compress_page(RAMState *rs, PageSearchStatus *pss,
      * much CPU resource.
      */
     if (block != pss->last_sent_block) {
-        flush_compressed_data(rs);
+        ram_flush_compressed_data(rs);
         return false;
     }

-    if (compress_page_with_multi_thread(block, offset) > 0) {
+    if (compress_page_with_multi_thread(block, offset, send_queued_data) > 0) {
         return true;
     }

@@ -3419,7 +3426,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
              * page is sent in one chunk.
              */
             if (migrate_postcopy_ram()) {
-                flush_compressed_data(rs);
+                ram_flush_compressed_data(rs);
             }

             /*
@@ -3512,7 +3519,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
         }
         qemu_mutex_unlock(&rs->bitmap_mutex);

-        flush_compressed_data(rs);
+        ram_flush_compressed_data(rs);
         ram_control_after_iterate(f, RAM_CONTROL_FINISH);
     }

--
2.30.2


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[PATCH 07/14] ram.c: Introduce whitespace (squash with next patch)

[Lukas Straub]

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Introduce whitespace to make it easier to reroll the series.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/migration/ram.c b/migration/ram.c
index 20428ccf42..475c04a18b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -602,6 +602,12 @@ static void *do_data_compress(void *opaque)
     return NULL;
 }

+
+
+/* split */
+
+
+
 static void compress_threads_save_cleanup(void)
 {
     int i, thread_count;
@@ -641,6 +647,12 @@ static void compress_threads_save_cleanup(void)
     comp_param = NULL;
 }

+
+
+/* split */
+
+
+
 static int compress_threads_save_setup(void)
 {
     int i, thread_count;
--
2.30.2


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[PATCH 08/14] ram.c: Move core compression code into its own file

[Lukas Straub]

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No functional changes intended.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/meson.build    |   5 +-
 migration/ram-compress.c | 273 +++++++++++++++++++++++++++++++++++++++
 migration/ram-compress.h |  65 ++++++++++
 migration/ram.c          | 255 +-----------------------------------
 4 files changed, 343 insertions(+), 255 deletions(-)
 create mode 100644 migration/ram-compress.c
 create mode 100644 migration/ram-compress.h

diff --git a/migration/meson.build b/migration/meson.build
index 0d1bb9f96e..262e3c9754 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -36,4 +36,7 @@ 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',
+                               'ram-compress.c',
+                               'target.c'))
diff --git a/migration/ram-compress.c b/migration/ram-compress.c
new file mode 100644
index 0000000000..77902a1d65
--- /dev/null
+++ b/migration/ram-compress.c
@@ -0,0 +1,273 @@
+/*
+ * 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 "migration.h"
+#include "io/channel-null.h"
+#include "exec/ram_addr.h"
+
+CompressionStats 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;
+
+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_use_compression() || !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_use_compression()) {
+        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(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;
+    int ret;
+
+    if (buffer_is_zero(p, TARGET_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, TARGET_PAGE_SIZE);
+    ret = qemu_put_compression_data(f, stream, source_buf, TARGET_PAGE_SIZE);
+    if (ret < 0) {
+        qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
+        error_report("compressed data failed!");
+        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 flush_compressed_data(int (send_queued_data(CompressParam *)))
+{
+    int idx, thread_count;
+
+    thread_count = migrate_compress_threads();
+
+    qemu_mutex_lock(&comp_done_lock);
+    for (idx = 0; idx < thread_count; idx++) {
+        while (!comp_param[idx].done) {
+            qemu_cond_wait(&comp_done_cond, &comp_done_lock);
+        }
+    }
+    qemu_mutex_unlock(&comp_done_lock);
+
+    for (idx = 0; idx < thread_count; idx++) {
+        qemu_mutex_lock(&comp_param[idx].mutex);
+        if (!comp_param[idx].quit) {
+            CompressParam *param = &comp_param[idx];
+            send_queued_data(param);
+            compress_reset_result(param);
+        }
+        qemu_mutex_unlock(&comp_param[idx].mutex);
+    }
+}
+
+static inline void set_compress_params(CompressParam *param, RAMBlock *block,
+                                       ram_addr_t offset)
+{
+    param->block = block;
+    param->offset = offset;
+    param->trigger = true;
+}
+
+int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset,
+                                int (send_queued_data(CompressParam *)))
+{
+    int idx, thread_count, pages = -1;
+    bool wait = migrate_compress_wait_thread();
+
+    thread_count = migrate_compress_threads();
+    qemu_mutex_lock(&comp_done_lock);
+retry:
+    for (idx = 0; idx < thread_count; idx++) {
+        if (comp_param[idx].done) {
+            CompressParam *param = &comp_param[idx];
+            qemu_mutex_lock(&param->mutex);
+            param->done = false;
+            send_queued_data(param);
+            compress_reset_result(param);
+            set_compress_params(param, block, offset);
+
+            qemu_cond_signal(&param->cond);
+            qemu_mutex_unlock(&param->mutex);
+            pages = 1;
+            break;
+        }
+    }
+
+    /*
+     * wait for the free thread if the user specifies 'compress-wait-thread',
+     * otherwise we will post the page out in the main thread as normal page.
+     */
+    if (pages < 0 && wait) {
+        qemu_cond_wait(&comp_done_cond, &comp_done_lock);
+        goto retry;
+    }
+    qemu_mutex_unlock(&comp_done_lock);
+
+    return pages;
+}
diff --git a/migration/ram-compress.h b/migration/ram-compress.h
new file mode 100644
index 0000000000..06570a799c
--- /dev/null
+++ b/migration/ram-compress.h
@@ -0,0 +1,65 @@
+/*
+ * 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.
+ */
+
+#ifndef QEMU_MIGRATION_COMPRESS_H
+#define QEMU_MIGRATION_COMPRESS_H
+
+#include "qemu-file.h"
+
+enum CompressResult {
+    RES_NONE = 0,
+    RES_ZEROPAGE = 1,
+    RES_COMPRESS = 2
+};
+typedef enum CompressResult CompressResult;
+
+struct CompressParam {
+    bool done;
+    bool quit;
+    bool trigger;
+    CompressResult result;
+    QEMUFile *file;
+    QemuMutex mutex;
+    QemuCond cond;
+    RAMBlock *block;
+    ram_addr_t offset;
+
+    /* internally used fields */
+    z_stream stream;
+    uint8_t *originbuf;
+};
+typedef struct CompressParam CompressParam;
+
+void compress_threads_save_cleanup(void);
+int compress_threads_save_setup(void);
+
+void flush_compressed_data(int (send_queued_data(CompressParam *)));
+int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset,
+                                int (send_queued_data(CompressParam *)));
+
+#endif
diff --git a/migration/ram.c b/migration/ram.c
index 475c04a18b..114901241e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -34,6 +34,7 @@
 #include "qemu/main-loop.h"
 #include "io/channel-null.h"
 #include "xbzrle.h"
+#include "ram-compress.h"
 #include "ram.h"
 #include "migration.h"
 #include "migration/register.h"
@@ -491,32 +492,6 @@ typedef struct MigrationOps MigrationOps;

 MigrationOps *migration_ops;

-CompressionStats compression_counters;
-
-enum CompressResult {
-    RES_NONE = 0,
-    RES_ZEROPAGE = 1,
-    RES_COMPRESS = 2
-};
-typedef enum CompressResult CompressResult;
-
-struct CompressParam {
-    bool done;
-    bool quit;
-    bool trigger;
-    CompressResult result;
-    QEMUFile *file;
-    QemuMutex mutex;
-    QemuCond cond;
-    RAMBlock *block;
-    ram_addr_t offset;
-
-    /* internally used fields */
-    z_stream stream;
-    uint8_t *originbuf;
-};
-typedef struct CompressParam CompressParam;
-
 struct DecompressParam {
     bool done;
     bool quit;
@@ -529,15 +504,6 @@ struct DecompressParam {
 };
 typedef struct DecompressParam DecompressParam;

-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;
-
 static QEMUFile *decomp_file;
 static DecompressParam *decomp_param;
 static QemuThread *decompress_threads;
@@ -546,10 +512,6 @@ static QemuCond decomp_done_cond;

 static int ram_save_host_page_urgent(PageSearchStatus *pss);

-static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
-                                           RAMBlock *block, ram_addr_t offset,
-                                           uint8_t *source_buf);
-
 /* NOTE: page is the PFN not real ram_addr_t. */
 static void pss_init(PageSearchStatus *pss, RAMBlock *rb, ram_addr_t page)
 {
@@ -568,39 +530,7 @@ static bool pss_overlap(PageSearchStatus *pss1, PageSearchStatus *pss2)
         (pss1->host_page_start == pss2->host_page_start);
 }

-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;
-}



@@ -608,44 +538,7 @@ static void *do_data_compress(void *opaque)



-static void compress_threads_save_cleanup(void)
-{
-    int i, thread_count;
-
-    if (!migrate_use_compression() || !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;
-}



@@ -653,49 +546,7 @@ static void compress_threads_save_cleanup(void)



-static int compress_threads_save_setup(void)
-{
-    int i, thread_count;

-    if (!migrate_use_compression()) {
-        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(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;
-}

 /**
  * save_page_header: write page header to wire
@@ -1484,32 +1335,6 @@ static int ram_save_multifd_page(QEMUFile *file, RAMBlock *block,
     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;
-    int ret;
-
-    if (buffer_is_zero(p, TARGET_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, TARGET_PAGE_SIZE);
-    ret = qemu_put_compression_data(f, stream, source_buf, TARGET_PAGE_SIZE);
-    if (ret < 0) {
-        qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
-        error_report("compressed data failed!");
-        return RES_NONE;
-    }
-    return RES_COMPRESS;
-}
-
 static void
 update_compress_thread_counts(const CompressParam *param, int bytes_xmit)
 {
@@ -1527,13 +1352,6 @@ update_compress_thread_counts(const CompressParam *param, int bytes_xmit)

 static bool save_page_use_compression(RAMState *rs);

-static inline void compress_reset_result(CompressParam *param)
-{
-    param->result = RES_NONE;
-    param->block = NULL;
-    param->offset = 0;
-}
-
 static int send_queued_data(CompressParam *param)
 {
     PageSearchStatus *pss = &ram_state->pss[RAM_CHANNEL_PRECOPY];
@@ -1568,31 +1386,6 @@ static int send_queued_data(CompressParam *param)
     return len;
 }

-static void flush_compressed_data(int (send_queued_data(CompressParam *)))
-{
-    int idx, thread_count;
-
-    thread_count = migrate_compress_threads();
-
-    qemu_mutex_lock(&comp_done_lock);
-    for (idx = 0; idx < thread_count; idx++) {
-        while (!comp_param[idx].done) {
-            qemu_cond_wait(&comp_done_cond, &comp_done_lock);
-        }
-    }
-    qemu_mutex_unlock(&comp_done_lock);
-
-    for (idx = 0; idx < thread_count; idx++) {
-        qemu_mutex_lock(&comp_param[idx].mutex);
-        if (!comp_param[idx].quit) {
-            CompressParam *param = &comp_param[idx];
-            send_queued_data(param);
-            compress_reset_result(param);
-        }
-        qemu_mutex_unlock(&comp_param[idx].mutex);
-    }
-}
-
 static void ram_flush_compressed_data(RAMState *rs)
 {
     if (!save_page_use_compression(rs)) {
@@ -1602,52 +1395,6 @@ static void ram_flush_compressed_data(RAMState *rs)
     flush_compressed_data(send_queued_data);
 }

-static inline void set_compress_params(CompressParam *param, RAMBlock *block,
-                                       ram_addr_t offset)
-{
-    param->block = block;
-    param->offset = offset;
-    param->trigger = true;
-}
-
-static int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset,
-                                int (send_queued_data(CompressParam *)))
-{
-    int idx, thread_count, pages = -1;
-    bool wait = migrate_compress_wait_thread();
-
-    thread_count = migrate_compress_threads();
-    qemu_mutex_lock(&comp_done_lock);
-retry:
-    for (idx = 0; idx < thread_count; idx++) {
-        if (comp_param[idx].done) {
-            CompressParam *param = &comp_param[idx];
-            qemu_mutex_lock(&param->mutex);
-            param->done = false;
-            send_queued_data(param);
-            compress_reset_result(param);
-            set_compress_params(param, block, offset);
-
-            qemu_cond_signal(&param->cond);
-            qemu_mutex_unlock(&param->mutex);
-            pages = 1;
-            break;
-        }
-    }
-
-    /*
-     * wait for the free thread if the user specifies 'compress-wait-thread',
-     * otherwise we will post the page out in the main thread as normal page.
-     */
-    if (pages < 0 && wait) {
-        qemu_cond_wait(&comp_done_cond, &comp_done_lock);
-        goto retry;
-    }
-    qemu_mutex_unlock(&comp_done_lock);
-
-    return pages;
-}
-
 #define PAGE_ALL_CLEAN 0
 #define PAGE_TRY_AGAIN 1
 #define PAGE_DIRTY_FOUND 2
--
2.30.2


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[PATCH 09/14] ram.c: Remove whitespace (squash with previous patch)

[Lukas Straub]

[-- Attachment #1: Type: text/plain, Size: 575 bytes --]

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 114901241e..31b9b0b9ec 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -530,24 +530,6 @@ static bool pss_overlap(PageSearchStatus *pss1, PageSearchStatus *pss2)
         (pss1->host_page_start == pss2->host_page_start);
 }

-
-
-
-
-/* split */
-
-
-
-
-
-
-
-/* split */
-
-
-
-
-
 /**
  * save_page_header: write page header to wire
  *
--
2.30.2


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[PATCH 10/14] ram.c: Move core decompression code into its own file

[Lukas Straub]

[-- Attachment #1: Type: text/plain, Size: 14271 bytes --]

No functional changes intended.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram-compress.c | 203 ++++++++++++++++++++++++++++++++++++++
 migration/ram-compress.h |   5 +
 migration/ram.c          | 204 ---------------------------------------
 3 files changed, 208 insertions(+), 204 deletions(-)

diff --git a/migration/ram-compress.c b/migration/ram-compress.c
index 77902a1d65..f75b8c3079 100644
--- a/migration/ram-compress.c
+++ b/migration/ram-compress.c
@@ -47,6 +47,24 @@ static QemuThread *compress_threads;
 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);
@@ -271,3 +289,188 @@ retry:

     return pages;
 }
+
+/* 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 = 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)
+{
+    int idx, thread_count;
+
+    if (!migrate_use_compression()) {
+        return 0;
+    }
+
+    thread_count = migrate_decompress_threads();
+    qemu_mutex_lock(&decomp_done_lock);
+    for (idx = 0; idx < thread_count; idx++) {
+        while (!decomp_param[idx].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_use_compression()) {
+        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_use_compression()) {
+        return 0;
+    }
+
+    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;
+        }
+
+        decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_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 idx, thread_count;
+
+    thread_count = migrate_decompress_threads();
+    QEMU_LOCK_GUARD(&decomp_done_lock);
+    while (true) {
+        for (idx = 0; idx < thread_count; idx++) {
+            if (decomp_param[idx].done) {
+                decomp_param[idx].done = false;
+                qemu_mutex_lock(&decomp_param[idx].mutex);
+                qemu_get_buffer(f, decomp_param[idx].compbuf, len);
+                decomp_param[idx].des = host;
+                decomp_param[idx].len = len;
+                qemu_cond_signal(&decomp_param[idx].cond);
+                qemu_mutex_unlock(&decomp_param[idx].mutex);
+                break;
+            }
+        }
+        if (idx < thread_count) {
+            break;
+        } else {
+            qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
+        }
+    }
+}
diff --git a/migration/ram-compress.h b/migration/ram-compress.h
index 06570a799c..6f7fe2f472 100644
--- a/migration/ram-compress.h
+++ b/migration/ram-compress.h
@@ -62,4 +62,9 @@ void flush_compressed_data(int (send_queued_data(CompressParam *)));
 int compress_page_with_multi_thread(RAMBlock *block, ram_addr_t offset,
                                 int (send_queued_data(CompressParam *)));

+int wait_for_decompress_done(void);
+void compress_threads_load_cleanup(void);
+int compress_threads_load_setup(QEMUFile *f);
+void decompress_data_with_multi_threads(QEMUFile *f, void *host, int len);
+
 #endif
diff --git a/migration/ram.c b/migration/ram.c
index 31b9b0b9ec..5a2486bf89 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -492,24 +492,6 @@ typedef struct MigrationOps MigrationOps;

 MigrationOps *migration_ops;

-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 int ram_save_host_page_urgent(PageSearchStatus *pss);

 /* NOTE: page is the PFN not real ram_addr_t. */
@@ -3467,192 +3449,6 @@ void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
     }
 }

-/* 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 = 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;
-}
-
-static int wait_for_decompress_done(void)
-{
-    int idx, thread_count;
-
-    if (!migrate_use_compression()) {
-        return 0;
-    }
-
-    thread_count = migrate_decompress_threads();
-    qemu_mutex_lock(&decomp_done_lock);
-    for (idx = 0; idx < thread_count; idx++) {
-        while (!decomp_param[idx].done) {
-            qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
-        }
-    }
-    qemu_mutex_unlock(&decomp_done_lock);
-    return qemu_file_get_error(decomp_file);
-}
-
-static void compress_threads_load_cleanup(void)
-{
-    int i, thread_count;
-
-    if (!migrate_use_compression()) {
-        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;
-}
-
-static int compress_threads_load_setup(QEMUFile *f)
-{
-    int i, thread_count;
-
-    if (!migrate_use_compression()) {
-        return 0;
-    }
-
-    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;
-        }
-
-        decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_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;
-}
-
-static void decompress_data_with_multi_threads(QEMUFile *f,
-                                               void *host, int len)
-{
-    int idx, thread_count;
-
-    thread_count = migrate_decompress_threads();
-    QEMU_LOCK_GUARD(&decomp_done_lock);
-    while (true) {
-        for (idx = 0; idx < thread_count; idx++) {
-            if (decomp_param[idx].done) {
-                decomp_param[idx].done = false;
-                qemu_mutex_lock(&decomp_param[idx].mutex);
-                qemu_get_buffer(f, decomp_param[idx].compbuf, len);
-                decomp_param[idx].des = host;
-                decomp_param[idx].len = len;
-                qemu_cond_signal(&decomp_param[idx].cond);
-                qemu_mutex_unlock(&decomp_param[idx].mutex);
-                break;
-            }
-        }
-        if (idx < thread_count) {
-            break;
-        } else {
-            qemu_cond_wait(&decomp_done_cond, &decomp_done_lock);
-        }
-    }
-}
-
 static void colo_init_ram_state(void)
 {
     ram_state_init(&ram_state);
--
2.30.2


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[PATCH 11/14] ram compress: Assert that the file buffer matches the result

[Lukas Straub]

[-- Attachment #1: Type: text/plain, Size: 3900 bytes --]

Before this series, "nothing to send" was handled by the file buffer
being empty. Now it is tracked via param->result.

Assert that the file buffer state matches the result.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/qemu-file.c    | 11 +++++++++++
 migration/qemu-file.h    |  1 +
 migration/ram-compress.c |  5 +++++
 migration/ram.c          |  2 ++
 4 files changed, 19 insertions(+)

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 102ab3b439..2b3f3f8549 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -887,6 +887,17 @@ 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.
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index 9d0155a2a1..15e5f189f0 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -113,6 +113,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 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
diff --git a/migration/ram-compress.c b/migration/ram-compress.c
index f75b8c3079..b75a9d2b9a 100644
--- a/migration/ram-compress.c
+++ b/migration/ram-compress.c
@@ -193,6 +193,8 @@ static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
     uint8_t *p = block->host + offset;
     int ret;

+    assert(qemu_file_buffer_empty(f));
+
     if (buffer_is_zero(p, TARGET_PAGE_SIZE)) {
         return RES_ZEROPAGE;
     }
@@ -207,6 +209,7 @@ static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
     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;
@@ -238,6 +241,7 @@ void flush_compressed_data(int (send_queued_data(CompressParam *)))
         if (!comp_param[idx].quit) {
             CompressParam *param = &comp_param[idx];
             send_queued_data(param);
+            assert(qemu_file_buffer_empty(param->file));
             compress_reset_result(param);
         }
         qemu_mutex_unlock(&comp_param[idx].mutex);
@@ -267,6 +271,7 @@ retry:
             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);

diff --git a/migration/ram.c b/migration/ram.c
index 5a2486bf89..7a8f540737 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1333,11 +1333,13 @@ static int send_queued_data(CompressParam *param)
     assert(block == pss->last_sent_block);

     if (param->result == RES_ZEROPAGE) {
+        assert(qemu_file_buffer_empty(param->file));
         len += save_page_header(pss, file, block, offset | RAM_SAVE_FLAG_ZERO);
         qemu_put_byte(file, 0);
         len += 1;
         ram_release_page(block->idstr, offset);
     } else if (param->result == RES_COMPRESS) {
+        assert(!qemu_file_buffer_empty(param->file));
         len += save_page_header(pss, file, block,
                                 offset | RAM_SAVE_FLAG_COMPRESS_PAGE);
         len += qemu_put_qemu_file(file, param->file);
--
2.30.2


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[PATCH 12/14] ram.c: Remove unused include after moving out code

[Lukas Straub]

[-- Attachment #1: Type: text/plain, Size: 463 bytes --]

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/ram.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index 7a8f540737..9072d70f7c 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -32,7 +32,6 @@
 #include "qemu/bitmap.h"
 #include "qemu/madvise.h"
 #include "qemu/main-loop.h"
-#include "io/channel-null.h"
 #include "xbzrle.h"
 #include "ram-compress.h"
 #include "ram.h"
--
2.30.2


[-- Attachment #2: OpenPGP digital signature --]
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[PATCH 13/14] ram-compress.c: Make target independent

[Lukas Straub]

[-- Attachment #1: Type: text/plain, Size: 3429 bytes --]

Make ram-compress.c target independent.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/meson.build    |  2 +-
 migration/ram-compress.c | 16 +++++++++-------
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/migration/meson.build b/migration/meson.build
index 262e3c9754..16f642031c 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -22,6 +22,7 @@ softmmu_ss.add(files(
   'migration.c',
   'multifd.c',
   'multifd-zlib.c',
+  'ram-compress.c',
   'postcopy-ram.c',
   'savevm.c',
   'socket.c',
@@ -38,5 +39,4 @@ softmmu_ss.add(when: zstd, if_true: files('multifd-zstd.c'))
 specific_ss.add(when: 'CONFIG_SOFTMMU',
                 if_true: files('dirtyrate.c',
                                'ram.c',
-                               'ram-compress.c',
                                'target.c'))
diff --git a/migration/ram-compress.c b/migration/ram-compress.c
index b75a9d2b9a..a75c6e0573 100644
--- a/migration/ram-compress.c
+++ b/migration/ram-compress.c
@@ -34,7 +34,8 @@
 #include "qemu/error-report.h"
 #include "migration.h"
 #include "io/channel-null.h"
-#include "exec/ram_addr.h"
+#include "exec/target_page.h"
+#include "exec/ramblock.h"

 CompressionStats compression_counters;

@@ -155,7 +156,7 @@ int compress_threads_save_setup(void)
     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(TARGET_PAGE_SIZE);
+        comp_param[i].originbuf = g_try_malloc(qemu_target_page_size());
         if (!comp_param[i].originbuf) {
             goto exit;
         }
@@ -195,7 +196,7 @@ static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,

     assert(qemu_file_buffer_empty(f));

-    if (buffer_is_zero(p, TARGET_PAGE_SIZE)) {
+    if (buffer_is_zero(p, qemu_target_page_size())) {
         return RES_ZEROPAGE;
     }

@@ -204,8 +205,8 @@ static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
      * so that we can catch up the error during compression and
      * decompression
      */
-    memcpy(source_buf, p, TARGET_PAGE_SIZE);
-    ret = qemu_put_compression_data(f, stream, source_buf, TARGET_PAGE_SIZE);
+    memcpy(source_buf, p, qemu_target_page_size());
+    ret = qemu_put_compression_data(f, stream, source_buf, qemu_target_page_size());
     if (ret < 0) {
         qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
         error_report("compressed data failed!");
@@ -335,7 +336,7 @@ static void *do_data_decompress(void *opaque)
             param->des = 0;
             qemu_mutex_unlock(&param->mutex);

-            pagesize = TARGET_PAGE_SIZE;
+            pagesize = qemu_target_page_size();

             ret = qemu_uncompress_data(&param->stream, des, pagesize,
                                        param->compbuf, len);
@@ -438,7 +439,8 @@ int compress_threads_load_setup(QEMUFile *f)
             goto exit;
         }

-        decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
+        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;
--
2.30.2


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[PATCH 14/14] migration: Initialize and cleanup decompression in migration.c

[Lukas Straub]

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This fixes compress with colo.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/migration.c | 9 +++++++++
 migration/ram.c       | 5 -----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index ae2025d9d8..cbdc10b840 100644
--- a/migration/migration.c
+++ b/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"
@@ -316,6 +317,7 @@ 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 */
@@ -598,6 +600,12 @@ 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);
@@ -663,6 +671,7 @@ fail:
     qemu_fclose(mis->from_src_file);

     multifd_load_cleanup();
+    compress_threads_load_cleanup();

     exit(EXIT_FAILURE);
 }
diff --git a/migration/ram.c b/migration/ram.c
index 9072d70f7c..e9a295fab9 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3559,10 +3559,6 @@ void colo_release_ram_cache(void)
  */
 static int ram_load_setup(QEMUFile *f, void *opaque)
 {
-    if (compress_threads_load_setup(f)) {
-        return -1;
-    }
-
     xbzrle_load_setup();
     ramblock_recv_map_init();

@@ -3578,7 +3574,6 @@ static int ram_load_cleanup(void *opaque)
     }

     xbzrle_load_cleanup();
-    compress_threads_load_cleanup();

     RAMBLOCK_FOREACH_NOT_IGNORED(rb) {
         g_free(rb->receivedmap);
--
2.30.2

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RE: [PATCH 00/14] migration/ram.c: Refactor compress code

[Zhang, Chen]

> -----Original Message-----
> From: qemu-devel-bounces+chen.zhang=intel.com@nongnu.org <qemu-
> devel-bounces+chen.zhang=intel.com@nongnu.org> On Behalf Of Lukas
> Straub
> Sent: Monday, April 3, 2023 1:56 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>; Juan Quintela
> <quintela@redhat.com>; Peter Xu <peterx@redhat.com>
> Subject: [PATCH 00/14] migration/ram.c: Refactor compress code
> 
> This series refactors the ram compress code.
> 
> It first removes ram.c dependencies from the core compress code, then
> moves it out to its own file. Finally, on the migration destination side the
> initialisation and cleanup of compress threads is moved out of ram.c to
> migration.c. This allows using COLO with compress enabled.
> 

Nice to see this optimization~
Support the ram compress feature will reduce COLO checkpoint network bandwidth requirements
And may improve COLO protected VM's performance.

Thanks
Chen

> This series is based on the following series:
> https://lore.kernel.org/qemu-
> devel/af76761aa6978071c5b8e9b872b697db465a5520.1680457631.git.lukasstr
> aub2@web.de/T/#t
> 
> Lukas Straub (14):
>   ram.c: Let the compress threads return a CompressResult enum
>   ram.c: Dont change param->block in the compress thread
>   ram.c: Reset result after sending queued data
>   ram.c: Do not call save_page_header() from compress threads
>   ram.c: Call update_compress_thread_counts from
>     compress_send_queued_data
>   ram.c: Remove last ram.c dependency from the core compress code
>   ram.c: Introduce whitespace (squash with next patch)
>   ram.c: Move core compression code into its own file
>   ram.c: Remove whitespace (squash with previous patch)
>   ram.c: Move core decompression code into its own file
>   ram compress: Assert that the file buffer matches the result
>   ram.c: Remove unused include after moving out code
>   ram-compress.c: Make target independent
>   migration: Initialize and cleanup decompression in migration.c
> 
>  migration/meson.build    |   5 +-
>  migration/migration.c    |   9 +
>  migration/qemu-file.c    |  11 +
>  migration/qemu-file.h    |   1 +
>  migration/ram-compress.c | 483
> ++++++++++++++++++++++++++++++++++++++
>  migration/ram-compress.h |  70 ++++++
>  migration/ram.c          | 490 +++------------------------------------
>  7 files changed, 615 insertions(+), 454 deletions(-)  create mode 100644
> migration/ram-compress.c  create mode 100644 migration/ram-compress.h
> 
> --
> 2.30.2

Re: [PATCH 01/14] ram.c: Let the compress threads return a CompressResult enum

[Philippe Mathieu-Daudé]

On 2/4/23 19:56, Lukas Straub wrote:
> This will be used in the next commits to move save_page_header()
> out of compress code.
> 
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>   migration/ram.c | 34 ++++++++++++++++++++++------------
>   1 file changed, 22 insertions(+), 12 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 9d1817ab7b..ca561e62bd 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -493,10 +493,17 @@ MigrationOps *migration_ops;
> 
>   CompressionStats compression_counters;
> 
> +enum CompressResult {
> +    RES_NONE = 0,

What about RES_INVALID?

> +    RES_ZEROPAGE = 1,
> +    RES_COMPRESS = 2
> +};


> -static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
> -                                 ram_addr_t offset, uint8_t *source_buf)
> +static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
> +                                           RAMBlock *block, ram_addr_t offset,
> +                                           uint8_t *source_buf)
>   {


>       if (ret < 0) {
>           qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
>           error_report("compressed data failed!");
> +        return RES_NONE;
>       }
> -    return false;
> +    return RES_COMPRESS;
>   }

Re: [PATCH 10/14] ram.c: Move core decompression code into its own file

[Philippe Mathieu-Daudé]

On 2/4/23 19:56, Lukas Straub wrote:
> No functional changes intended.
> 
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>   migration/ram-compress.c | 203 ++++++++++++++++++++++++++++++++++++++
>   migration/ram-compress.h |   5 +
>   migration/ram.c          | 204 ---------------------------------------
>   3 files changed, 208 insertions(+), 204 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH 13/14] ram-compress.c: Make target independent

[Philippe Mathieu-Daudé]

On 2/4/23 19:56, Lukas Straub wrote:
> Make ram-compress.c target independent.
> 
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>   migration/meson.build    |  2 +-
>   migration/ram-compress.c | 16 +++++++++-------
>   2 files changed, 10 insertions(+), 8 deletions(-)

\o/

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH 12/14] ram.c: Remove unused include after moving out code

[Philippe Mathieu-Daudé]

On 2/4/23 19:56, Lukas Straub wrote:
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>   migration/ram.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 7a8f540737..9072d70f7c 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -32,7 +32,6 @@
>   #include "qemu/bitmap.h"
>   #include "qemu/madvise.h"
>   #include "qemu/main-loop.h"
> -#include "io/channel-null.h"

To squash with patch #8 "ram.c: Move core compression code into its own 
file".

Re: [PATCH 01/14] ram.c: Let the compress threads return a CompressResult enum

[Lukas Straub]

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On Mon, 3 Apr 2023 09:25:41 +0200
Philippe Mathieu-Daudé <philmd@linaro.org> wrote:

> On 2/4/23 19:56, Lukas Straub wrote:
> > This will be used in the next commits to move save_page_header()
> > out of compress code.
> > 
> > Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> > ---
> >   migration/ram.c | 34 ++++++++++++++++++++++------------
> >   1 file changed, 22 insertions(+), 12 deletions(-)
> > 
> > diff --git a/migration/ram.c b/migration/ram.c
> > index 9d1817ab7b..ca561e62bd 100644
> > --- a/migration/ram.c
> > +++ b/migration/ram.c
> > @@ -493,10 +493,17 @@ MigrationOps *migration_ops;
> > 
> >   CompressionStats compression_counters;
> > 
> > +enum CompressResult {
> > +    RES_NONE = 0,  
> 
> What about RES_INVALID?

I think RES_NONE is more accurate, because having no result is a common
case. The submit side first handles the result from a previous
compression and then submits the new compression request. And for
example, when submitting the very first request to the thread there
won't be a previous result. Or when submitting after the threads where
flushed.

I just opted to return RES_NONE on error, because it seems more correct.

> > +    RES_ZEROPAGE = 1,
> > +    RES_COMPRESS = 2
> > +};  
> 
> 
> > -static bool do_compress_ram_page(QEMUFile *f, z_stream *stream, RAMBlock *block,
> > -                                 ram_addr_t offset, uint8_t *source_buf)
> > +static CompressResult do_compress_ram_page(QEMUFile *f, z_stream *stream,
> > +                                           RAMBlock *block, ram_addr_t offset,
> > +                                           uint8_t *source_buf)
> >   {  
> 
> 
> >       if (ret < 0) {
> >           qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
> >           error_report("compressed data failed!");
> > +        return RES_NONE;
> >       }
> > -    return false;
> > +    return RES_COMPRESS;
> >   }  
> 



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Re: [PATCH 00/14] migration/ram.c: Refactor compress code

[Lukas Straub]

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On Sun, 2 Apr 2023 17:55:59 +0000
Lukas Straub <lukasstraub2@web.de> wrote:

> This series refactors the ram compress code.
> 
> It first removes ram.c dependencies from the core compress code, then
> moves it out to its own file. Finally, on the migration destination side
> the initialisation and cleanup of compress threads is moved out of ram.c
> to migration.c. This allows using COLO with compress enabled.
> 
> This series is based on the following series:
> https://lore.kernel.org/qemu-devel/af76761aa6978071c5b8e9b872b697db465a5520.1680457631.git.lukasstraub2@web.de/T/#t
> 

Hmm, I'm wondering if I should add postcopy+compress tests in this
series? Because if we start this, the test matrix really will explode.

Regards,
Lukas Straub

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Re: [PATCH 00/14] migration/ram.c: Refactor compress code

[Peter Xu]

On Wed, Apr 05, 2023 at 02:44:13PM +0000, Lukas Straub wrote:
> On Sun, 2 Apr 2023 17:55:59 +0000
> Lukas Straub <lukasstraub2@web.de> wrote:
> 
> > This series refactors the ram compress code.
> > 
> > It first removes ram.c dependencies from the core compress code, then
> > moves it out to its own file. Finally, on the migration destination side
> > the initialisation and cleanup of compress threads is moved out of ram.c
> > to migration.c. This allows using COLO with compress enabled.
> > 
> > This series is based on the following series:
> > https://lore.kernel.org/qemu-devel/af76761aa6978071c5b8e9b872b697db465a5520.1680457631.git.lukasstraub2@web.de/T/#t
> > 
> 
> Hmm, I'm wondering if I should add postcopy+compress tests in this
> series? Because if we start this, the test matrix really will explode.

Do you perhaps mean when compress added to the existing (and already large)
postcopy test matrix?

I assume we can still add one for vanilla postcopy+compress, so it still
covers the major parts.  Or, add the compress test with the postcopy test
with most features enabled? The most comprehensive one in qtest should be:

/x86_64/migration/postcopy/preempt/recovery/tls/psk

That covers postcopy+preempt+tls, meanwhile there'll be an emulation of
network failure too during postcopy and test recovering from it.

-- 
Peter Xu