multifd: Make no compression operations into its own structure

It will be used later.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

---

No comp value needs to be zero.

migration/migration.c

@@ -2245,6 +2245,15 @@ int migrate_multifd_channels(void)
     return s->parameters.multifd_channels;
 }
 
+MultiFDCompression migrate_multifd_compression(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->parameters.multifd_compression;
+}
+
 int migrate_use_xbzrle(void)
 {
     MigrationState *s;

migration/migration.h

@@ -300,6 +300,7 @@ bool migrate_auto_converge(void);
 bool migrate_use_multifd(void);
 bool migrate_pause_before_switchover(void);
 int migrate_multifd_channels(void);
+MultiFDCompression migrate_multifd_compression(void);
 
 int migrate_use_xbzrle(void);
 int64_t migrate_xbzrle_cache_size(void);

migration/multifd.c

@@ -38,6 +38,134 @@ typedef struct {
     uint64_t unused2[4];    /* Reserved for future use */
 } __attribute__((packed)) MultiFDInit_t;
 
+/* Multifd without compression */
+
+/**
+ * nocomp_send_setup: setup send side
+ *
+ * For no compression this function does nothing.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @errp: pointer to an error
+ */
+static int nocomp_send_setup(MultiFDSendParams *p, Error **errp)
+{
+    return 0;
+}
+
+/**
+ * nocomp_send_cleanup: cleanup send side
+ *
+ * For no compression this function does nothing.
+ *
+ * @p: Params for the channel that we are using
+ */
+static void nocomp_send_cleanup(MultiFDSendParams *p, Error **errp)
+{
+    return;
+}
+
+/**
+ * nocomp_send_prepare: prepare date to be able to send
+ *
+ * For no compression we just have to calculate the size of the
+ * packet.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @used: number of pages used
+ * @errp: pointer to an error
+ */
+static int nocomp_send_prepare(MultiFDSendParams *p, uint32_t used,
+                               Error **errp)
+{
+    p->next_packet_size = used * qemu_target_page_size();
+    p->flags |= MULTIFD_FLAG_NOCOMP;
+    return 0;
+}
+
+/**
+ * nocomp_send_write: do the actual write of the data
+ *
+ * For no compression we just have to write the data.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @used: number of pages used
+ * @errp: pointer to an error
+ */
+static int nocomp_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
+{
+    return qio_channel_writev_all(p->c, p->pages->iov, used, errp);
+}
+
+/**
+ * nocomp_recv_setup: setup receive side
+ *
+ * For no compression this function does nothing.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @errp: pointer to an error
+ */
+static int nocomp_recv_setup(MultiFDRecvParams *p, Error **errp)
+{
+    return 0;
+}
+
+/**
+ * nocomp_recv_cleanup: setup receive side
+ *
+ * For no compression this function does nothing.
+ *
+ * @p: Params for the channel that we are using
+ */
+static void nocomp_recv_cleanup(MultiFDRecvParams *p)
+{
+}
+
+/**
+ * nocomp_recv_pages: read the data from the channel into actual pages
+ *
+ * For no compression we just need to read things into the correct place.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @used: number of pages used
+ * @errp: pointer to an error
+ */
+static int nocomp_recv_pages(MultiFDRecvParams *p, uint32_t used, Error **errp)
+{
+    uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
+
+    if (flags != MULTIFD_FLAG_NOCOMP) {
+        error_setg(errp, "multifd %d: flags received %x flags expected %x",
+                   p->id, flags, MULTIFD_FLAG_NOCOMP);
+        return -1;
+    }
+    return qio_channel_readv_all(p->c, p->pages->iov, used, errp);
+}
+
+static MultiFDMethods multifd_nocomp_ops = {
+    .send_setup = nocomp_send_setup,
+    .send_cleanup = nocomp_send_cleanup,
+    .send_prepare = nocomp_send_prepare,
+    .send_write = nocomp_send_write,
+    .recv_setup = nocomp_recv_setup,
+    .recv_cleanup = nocomp_recv_cleanup,
+    .recv_pages = nocomp_recv_pages
+};
+
+static MultiFDMethods *multifd_ops[MULTIFD_COMPRESSION__MAX] = {
+    [MULTIFD_COMPRESSION_NONE] = &multifd_nocomp_ops,
+};
+
 static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
 {
     MultiFDInit_t msg = {};
@@ -246,6 +374,8 @@ struct {
      * We will use atomic operations.  Only valid values are 0 and 1.
      */
     int exiting;
+    /* multifd ops */
+    MultiFDMethods *ops;
 } *multifd_send_state;
 
 /*
@@ -397,6 +527,7 @@ void multifd_save_cleanup(void)
     }
     for (i = 0; i < migrate_multifd_channels(); i++) {
         MultiFDSendParams *p = &multifd_send_state->params[i];
+        Error *local_err = NULL;
 
         socket_send_channel_destroy(p->c);
         p->c = NULL;
@@ -410,6 +541,10 @@ void multifd_save_cleanup(void)
         p->packet_len = 0;
         g_free(p->packet);
         p->packet = NULL;
+        multifd_send_state->ops->send_cleanup(p, &local_err);
+        if (local_err) {
+            migrate_set_error(migrate_get_current(), local_err);
+        }
     }
     qemu_sem_destroy(&multifd_send_state->channels_ready);
     g_free(multifd_send_state->params);
@@ -494,7 +629,14 @@ static void *multifd_send_thread(void *opaque)
             uint64_t packet_num = p->packet_num;
             flags = p->flags;
 
-            p->next_packet_size = used * qemu_target_page_size();
+            if (used) {
+                ret = multifd_send_state->ops->send_prepare(p, used,
+                                                            &local_err);
+                if (ret != 0) {
+                    qemu_mutex_unlock(&p->mutex);
+                    break;
+                }
+            }
             multifd_send_fill_packet(p);
             p->flags = 0;
             p->num_packets++;
@@ -513,8 +655,7 @@ static void *multifd_send_thread(void *opaque)
             }
 
             if (used) {
-                ret = qio_channel_writev_all(p->c, p->pages->iov,
-                                             used, &local_err);
+                ret = multifd_send_state->ops->send_write(p, used, &local_err);
                 if (ret != 0) {
                     break;
                 }
@@ -604,6 +745,7 @@ int multifd_save_setup(Error **errp)
     multifd_send_state->pages = multifd_pages_init(page_count);
     qemu_sem_init(&multifd_send_state->channels_ready, 0);
     atomic_set(&multifd_send_state->exiting, 0);
+    multifd_send_state->ops = multifd_ops[migrate_multifd_compression()];
 
     for (i = 0; i < thread_count; i++) {
         MultiFDSendParams *p = &multifd_send_state->params[i];
@@ -623,6 +765,18 @@ int multifd_save_setup(Error **errp)
         p->name = g_strdup_printf("multifdsend_%d", i);
         socket_send_channel_create(multifd_new_send_channel_async, p);
     }
+
+    for (i = 0; i < thread_count; i++) {
+        MultiFDSendParams *p = &multifd_send_state->params[i];
+        Error *local_err = NULL;
+        int ret;
+
+        ret = multifd_send_state->ops->send_setup(p, &local_err);
+        if (ret) {
+            error_propagate(errp, local_err);
+            return ret;
+        }
+    }
     return 0;
 }
 
@@ -634,6 +788,8 @@ struct {
     QemuSemaphore sem_sync;
     /* global number of generated multifd packets */
     uint64_t packet_num;
+    /* multifd ops */
+    MultiFDMethods *ops;
 } *multifd_recv_state;
 
 static void multifd_recv_terminate_threads(Error *err)
@@ -673,7 +829,6 @@ static void multifd_recv_terminate_threads(Error *err)
 int multifd_load_cleanup(Error **errp)
 {
     int i;
-    int ret = 0;
 
     if (!migrate_use_multifd()) {
         return 0;
@@ -706,6 +861,7 @@ int multifd_load_cleanup(Error **errp)
         p->packet_len = 0;
         g_free(p->packet);
         p->packet = NULL;
+        multifd_recv_state->ops->recv_cleanup(p);
     }
     qemu_sem_destroy(&multifd_recv_state->sem_sync);
     g_free(multifd_recv_state->params);
@@ -713,7 +869,7 @@ int multifd_load_cleanup(Error **errp)
     g_free(multifd_recv_state);
     multifd_recv_state = NULL;
 
-    return ret;
+    return 0;
 }
 
 void multifd_recv_sync_main(void)
@@ -778,6 +934,8 @@ static void *multifd_recv_thread(void *opaque)
 
         used = p->pages->used;
         flags = p->flags;
+        /* recv methods don't know how to handle the SYNC flag */
+        p->flags &= ~MULTIFD_FLAG_SYNC;
         trace_multifd_recv(p->id, p->packet_num, used, flags,
                            p->next_packet_size);
         p->num_packets++;
@@ -785,8 +943,7 @@ static void *multifd_recv_thread(void *opaque)
         qemu_mutex_unlock(&p->mutex);
 
         if (used) {
-            ret = qio_channel_readv_all(p->c, p->pages->iov,
-                                        used, &local_err);
+            ret = multifd_recv_state->ops->recv_pages(p, used, &local_err);
             if (ret != 0) {
                 break;
             }
@@ -825,6 +982,7 @@ int multifd_load_setup(Error **errp)
     multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count);
     atomic_set(&multifd_recv_state->count, 0);
     qemu_sem_init(&multifd_recv_state->sem_sync, 0);
+    multifd_recv_state->ops = multifd_ops[migrate_multifd_compression()];
 
     for (i = 0; i < thread_count; i++) {
         MultiFDRecvParams *p = &multifd_recv_state->params[i];
@@ -839,6 +997,18 @@ int multifd_load_setup(Error **errp)
         p->packet = g_malloc0(p->packet_len);
         p->name = g_strdup_printf("multifdrecv_%d", i);
     }
+
+    for (i = 0; i < thread_count; i++) {
+        MultiFDRecvParams *p = &multifd_recv_state->params[i];
+        Error *local_err = NULL;
+        int ret;
+
+        ret = multifd_recv_state->ops->recv_setup(p, &local_err);
+        if (ret) {
+            error_propagate(errp, local_err);
+            return ret;
+        }
+    }
     return 0;
 }
 
@@ -896,4 +1066,3 @@ bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp)
     return atomic_read(&multifd_recv_state->count) ==
            migrate_multifd_channels();
 }
-

migration/multifd.h

@@ -25,6 +25,11 @@ int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset);
 
 #define MULTIFD_FLAG_SYNC (1 << 0)
 
+/* We reserve 3 bits for compression methods */
+#define MULTIFD_FLAG_COMPRESSION_MASK (7 << 1)
+/* we need to be compatible. Before compression value was 0 */
+#define MULTIFD_FLAG_NOCOMP (0 << 1)
+
 /* This value needs to be a multiple of qemu_target_page_size() */
 #define MULTIFD_PACKET_SIZE (512 * 1024)
 
@@ -96,6 +101,8 @@ typedef struct {
     uint64_t num_pages;
     /* syncs main thread and channels */
     QemuSemaphore sem_sync;
+    /* used for compression methods */
+    void *data;
 }  MultiFDSendParams;
 
 typedef struct {
@@ -133,7 +140,26 @@ typedef struct {
     uint64_t num_pages;
     /* syncs main thread and channels */
     QemuSemaphore sem_sync;
+    /* used for de-compression methods */
+    void *data;
 } MultiFDRecvParams;
 
+typedef struct {
+    /* Setup for sending side */
+    int (*send_setup)(MultiFDSendParams *p, Error **errp);
+    /* Cleanup for sending side */
+    void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
+    /* Prepare the send packet */
+    int (*send_prepare)(MultiFDSendParams *p, uint32_t used, Error **errp);
+    /* Write the send packet */
+    int (*send_write)(MultiFDSendParams *p, uint32_t used, Error **errp);
+    /* Setup for receiving side */
+    int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
+    /* Cleanup for receiving side */
+    void (*recv_cleanup)(MultiFDRecvParams *p);
+    /* Read all pages */
+    int (*recv_pages)(MultiFDRecvParams *p, uint32_t used, Error **errp);
+} MultiFDMethods;
+
 #endif
 

migration/ram.c

@@ -43,6 +43,7 @@
 #include "page_cache.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
+#include "qapi/qapi-types-migration.h"
 #include "qapi/qapi-events-migration.h"
 #include "qapi/qmp/qerror.h"
 #include "trace.h"