[Qemu-devel] [PULL 35/57] migration_completion: Take current state

[Juan Quintela]

From: "Dr. David Alan Gilbert" 

Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we
complete migration, and we need to know which we expect to be
in to change state safely.

Signed-off-by: Dr. David Alan Gilbert 
Reviewed-by: Juan Quintela 
Signed-off-by: Juan Quintela 
---
 include/migration/migration.h|   5 ++
 include/migration/postcopy-ram.h |  35 
 include/qemu/typedefs.h  |   1 +
 migration/migration.c|   1 +
 migration/postcopy-ram.c | 126 +++
 migration/ram.c  | 181 ++-
 migration/savevm.c   |   2 -
 trace-events |   6 ++
 8 files changed, 354 insertions(+), 3 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 219032d..b382d77 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -199,6 +199,11 @@ double xbzrle_mig_cache_miss_rate(void);

 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
+/* For outgoing discard bitmap */
+int ram_postcopy_send_discard_bitmap(MigrationState *ms);
+/* For incoming postcopy discard */
+int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
+  uint64_t start, size_t length);

 /**
  * @migrate_add_blocker - prevent migration from proceeding
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index d81934f..de79fa7 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -16,4 +16,39 @@
 /* Return true if the host supports everything we need to do postcopy-ram */
 bool postcopy_ram_supported_by_host(void);

+/*
+ * Discard the contents of 'length' bytes from 'start'
+ * We can assume that if we've been called postcopy_ram_hosttest returned true
+ */
+int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
+   size_t length);
+
+
+/*
+ * Called at the start of each RAMBlock by the bitmap code.
+ * 'offset' is the bitmap offset of the named RAMBlock in the migration
+ * bitmap.
+ * Returns a new PDS
+ */
+PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
+ unsigned long offset,
+ const char *name);
+
+/*
+ * Called by the bitmap code for each chunk to discard.
+ * May send a discard message, may just leave it queued to
+ * be sent later.
+ * @start,@length: a range of pages in the migration bitmap in the
+ *  RAM block passed to postcopy_discard_send_init() (length=1 is one page)
+ */
+void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
+ unsigned long start, unsigned long length);
+
+/*
+ * Called at the end of each RAMBlock by the bitmap code.
+ * Sends any outstanding discard messages, frees the PDS.
+ */
+void postcopy_discard_send_finish(MigrationState *ms,
+  PostcopyDiscardState *pds);
+
 #endif
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index f7e0ed0..6b1093d 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -67,6 +67,7 @@ typedef struct PCMachineState PCMachineState;
 typedef struct PCMachineClass PCMachineClass;
 typedef struct PCMCIACardState PCMCIACardState;
 typedef struct PixelFormat PixelFormat;
+typedef struct PostcopyDiscardState PostcopyDiscardState;
 typedef struct PropertyInfo PropertyInfo;
 typedef struct Property Property;
 typedef struct QEMUBH QEMUBH;
diff --git a/migration/migration.c b/migration/migration.c
index 2acd0e6..afc863a 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -24,6 +24,7 @@
 #include "qemu/sockets.h"
 #include "qemu/rcu.h"
 #include "migration/block.h"
+#include "migration/postcopy-ram.h"
 #include "qemu/thread.h"
 #include "qmp-commands.h"
 #include "trace.h"
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index cdd0168..261feda 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -27,6 +27,24 @@
 #include "qemu/error-report.h"
 #include "trace.h"

+/* Arbitrary limit on size of each discard command,
+ * keeps them around ~200 bytes
+ */
+#define MAX_DISCARDS_PER_COMMAND 12
+
+struct PostcopyDiscardState {
+const char *ramblock_name;
+uint64_t offset; /* Bitmap entry for the 1st bit of this RAMBlock */
+uint16_t cur_entry;
+/*
+ * Start and length of a discard range (bytes)
+ */
+uint64_t start_list[MAX_DISCARDS_PER_COMMAND];
+uint64_t length_list[MAX_DISCARDS_PER_COMMAND];
+unsigned int nsentwords;
+unsigned int nsentcmds;
+};
+
 /* Postcopy needs to detect accesses to pages that haven't yet been copied
  * across, and efficiently map new pages in, the 

[Qemu-devel] [PULL 35/57] migration_completion: Take current state

[Juan Quintela]

From: "Dr. David Alan Gilbert" 

Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we
complete migration, and we need to know which we expect to be
in to change state safely.

Signed-off-by: Dr. David Alan Gilbert 
Reviewed-by: Juan Quintela 
Signed-off-by: Juan Quintela 
---
 include/migration/migration.h|   5 ++
 include/migration/postcopy-ram.h |  35 
 include/qemu/typedefs.h  |   1 +
 migration/migration.c|   1 +
 migration/postcopy-ram.c | 126 +++
 migration/ram.c  | 181 ++-
 migration/savevm.c   |   2 -
 trace-events |   6 ++
 8 files changed, 354 insertions(+), 3 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 219032d..b382d77 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -199,6 +199,11 @@ double xbzrle_mig_cache_miss_rate(void);

 void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
 void ram_debug_dump_bitmap(unsigned long *todump, bool expected);
+/* For outgoing discard bitmap */
+int ram_postcopy_send_discard_bitmap(MigrationState *ms);
+/* For incoming postcopy discard */
+int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
+  uint64_t start, size_t length);

 /**
  * @migrate_add_blocker - prevent migration from proceeding
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index d81934f..de79fa7 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -16,4 +16,39 @@
 /* Return true if the host supports everything we need to do postcopy-ram */
 bool postcopy_ram_supported_by_host(void);

+/*
+ * Discard the contents of 'length' bytes from 'start'
+ * We can assume that if we've been called postcopy_ram_hosttest returned true
+ */
+int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
+   size_t length);
+
+
+/*
+ * Called at the start of each RAMBlock by the bitmap code.
+ * 'offset' is the bitmap offset of the named RAMBlock in the migration
+ * bitmap.
+ * Returns a new PDS
+ */
+PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms,
+ unsigned long offset,
+ const char *name);
+
+/*
+ * Called by the bitmap code for each chunk to discard.
+ * May send a discard message, may just leave it queued to
+ * be sent later.
+ * @start,@length: a range of pages in the migration bitmap in the
+ *  RAM block passed to postcopy_discard_send_init() (length=1 is one page)
+ */
+void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds,
+ unsigned long start, unsigned long length);
+
+/*
+ * Called at the end of each RAMBlock by the bitmap code.
+ * Sends any outstanding discard messages, frees the PDS.
+ */
+void postcopy_discard_send_finish(MigrationState *ms,
+  PostcopyDiscardState *pds);
+
 #endif
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index f7e0ed0..6b1093d 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -67,6 +67,7 @@ typedef struct PCMachineState PCMachineState;
 typedef struct PCMachineClass PCMachineClass;
 typedef struct PCMCIACardState PCMCIACardState;
 typedef struct PixelFormat PixelFormat;
+typedef struct PostcopyDiscardState PostcopyDiscardState;
 typedef struct PropertyInfo PropertyInfo;
 typedef struct Property Property;
 typedef struct QEMUBH QEMUBH;
diff --git a/migration/migration.c b/migration/migration.c
index 76aa524..de14359 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -24,6 +24,7 @@
 #include "qemu/sockets.h"
 #include "qemu/rcu.h"
 #include "migration/block.h"
+#include "migration/postcopy-ram.h"
 #include "qemu/thread.h"
 #include "qmp-commands.h"
 #include "trace.h"
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index cdd0168..261feda 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -27,6 +27,24 @@
 #include "qemu/error-report.h"
 #include "trace.h"

+/* Arbitrary limit on size of each discard command,
+ * keeps them around ~200 bytes
+ */
+#define MAX_DISCARDS_PER_COMMAND 12
+
+struct PostcopyDiscardState {
+const char *ramblock_name;
+uint64_t offset; /* Bitmap entry for the 1st bit of this RAMBlock */
+uint16_t cur_entry;
+/*
+ * Start and length of a discard range (bytes)
+ */
+uint64_t start_list[MAX_DISCARDS_PER_COMMAND];
+uint64_t length_list[MAX_DISCARDS_PER_COMMAND];
+unsigned int nsentwords;
+unsigned int nsentcmds;
+};
+
 /* Postcopy needs to detect accesses to pages that haven't yet been copied
  * across, and efficiently map new pages in, the