[PATCH v7 10/12] multifd: Support for zero pages transmission

[Juan Quintela <quintela@redhat.com>]

This patch adds counters and similar.  Logic will be added on the
following patch.

Signed-off-by: Juan Quintela <quintela@redhat.com>

---

Added counters for duplicated/non duplicated pages.
Removed reviewed by from David.
Add total_zero_pages
---
 migration/multifd.h    | 17 ++++++++++++++++-
 migration/multifd.c    | 36 +++++++++++++++++++++++++++++-------
 migration/ram.c        |  2 --
 migration/trace-events |  8 ++++----
 4 files changed, 49 insertions(+), 14 deletions(-)

diff --git a/migration/multifd.h b/migration/multifd.h
index cd389d18d2..a1b852200d 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -47,7 +47,10 @@ typedef struct {
     /* size of the next packet that contains pages */
     uint32_t next_packet_size;
     uint64_t packet_num;
-    uint64_t unused[4];    /* Reserved for future use */
+    /* zero pages */
+    uint32_t zero_pages;
+    uint32_t unused32[1];    /* Reserved for future use */
+    uint64_t unused64[3];    /* Reserved for future use */
     char ramblock[256];
     uint64_t offset[];
 } __attribute__((packed)) MultiFDPacket_t;
@@ -127,6 +130,8 @@ typedef struct {
     uint64_t num_packets;
     /* non zero pages sent through this channel */
     uint64_t total_normal_pages;
+    /* zero pages sent through this channel */
+    uint64_t total_zero_pages;
     /* buffers to send */
     struct iovec *iov;
     /* number of iovs used */
@@ -135,6 +140,10 @@ typedef struct {
     ram_addr_t *normal;
     /* num of non zero pages */
     uint32_t normal_num;
+    /* Pages that are  zero */
+    ram_addr_t *zero;
+    /* num of zero pages */
+    uint32_t zero_num;
     /* used for compression methods */
     void *data;
 }  MultiFDSendParams;
@@ -184,12 +193,18 @@ typedef struct {
     uint8_t *host;
     /* non zero pages recv through this channel */
     uint64_t total_normal_pages;
+    /* zero pages recv through this channel */
+    uint64_t total_zero_pages;
     /* buffers to recv */
     struct iovec *iov;
     /* Pages that are not zero */
     ram_addr_t *normal;
     /* num of non zero pages */
     uint32_t normal_num;
+    /* Pages that are  zero */
+    ram_addr_t *zero;
+    /* num of zero pages */
+    uint32_t zero_num;
     /* used for de-compression methods */
     void *data;
 } MultiFDRecvParams;
diff --git a/migration/multifd.c b/migration/multifd.c
index 68fc9f8e88..4473d9f834 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -263,6 +263,7 @@ static void multifd_send_fill_packet(MultiFDSendParams *p)
     packet->normal_pages = cpu_to_be32(p->normal_num);
     packet->next_packet_size = cpu_to_be32(p->next_packet_size);
     packet->packet_num = cpu_to_be64(p->packet_num);
+    packet->zero_pages = cpu_to_be32(p->zero_num);
 
     if (p->pages->block) {
         strncpy(packet->ramblock, p->pages->block->idstr, 256);
@@ -323,7 +324,15 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
     p->next_packet_size = be32_to_cpu(packet->next_packet_size);
     p->packet_num = be64_to_cpu(packet->packet_num);
 
-    if (p->normal_num == 0) {
+    p->zero_num = be32_to_cpu(packet->zero_pages);
+    if (p->zero_num > packet->pages_alloc - p->normal_num) {
+        error_setg(errp, "multifd: received packet "
+                   "with %u zero pages and expected maximum pages are %u",
+                   p->zero_num, packet->pages_alloc - p->normal_num) ;
+        return -1;
+    }
+
+    if (p->normal_num == 0 && p->zero_num == 0) {
         return 0;
     }
 
@@ -432,6 +441,8 @@ static int multifd_send_pages(QEMUFile *f)
     ram_counters.multifd_bytes += p->sent_bytes;
     qemu_file_acct_rate_limit(f, p->sent_bytes);
     p->sent_bytes = 0;
+    ram_counters.normal += p->normal_num;
+    ram_counters.duplicate += p->zero_num;
     qemu_mutex_unlock(&p->mutex);
     qemu_sem_post(&p->sem);
 
@@ -545,6 +556,8 @@ void multifd_save_cleanup(void)
         p->iov = NULL;
         g_free(p->normal);
         p->normal = NULL;
+        g_free(p->zero);
+        p->zero = NULL;
         multifd_send_state->ops->send_cleanup(p, &local_err);
         if (local_err) {
             migrate_set_error(migrate_get_current(), local_err);
@@ -666,6 +679,7 @@ static void *multifd_send_thread(void *opaque)
             qemu_mutex_unlock(&p->mutex);
 
             p->normal_num = 0;
+            p->zero_num = 0;
 
             if (use_zero_copy_send) {
                 p->iovs_num = 0;
@@ -687,8 +701,8 @@ static void *multifd_send_thread(void *opaque)
             }
             multifd_send_fill_packet(p);
 
-            trace_multifd_send(p->id, packet_num, p->normal_num, p->flags,
-                               p->next_packet_size);
+            trace_multifd_send(p->id, packet_num, p->normal_num, p->zero_num,
+                               p->flags, p->next_packet_size);
 
             if (use_zero_copy_send) {
                 /* Send header first, without zerocopy */
@@ -712,6 +726,7 @@ static void *multifd_send_thread(void *opaque)
             qemu_mutex_lock(&p->mutex);
             p->num_packets++;
             p->total_normal_pages += p->normal_num;
+            p->total_zero_pages += p->zero_num;
             p->pages->num = 0;
             p->pages->block = NULL;
             p->sent_bytes += p->packet_len;;
@@ -753,7 +768,8 @@ out:
     qemu_mutex_unlock(&p->mutex);
 
     rcu_unregister_thread();
-    trace_multifd_send_thread_end(p->id, p->num_packets, p->total_normal_pages);
+    trace_multifd_send_thread_end(p->id, p->num_packets, p->total_normal_pages,
+                                  p->total_zero_pages);
 
     return NULL;
 }
@@ -938,6 +954,7 @@ int multifd_save_setup(Error **errp)
         p->normal = g_new0(ram_addr_t, page_count);
         p->page_size = qemu_target_page_size();
         p->page_count = page_count;
+        p->zero = g_new0(ram_addr_t, page_count);
 
         if (migrate_use_zero_copy_send()) {
             p->write_flags = QIO_CHANNEL_WRITE_FLAG_ZERO_COPY;
@@ -1046,6 +1063,8 @@ int multifd_load_cleanup(Error **errp)
         p->iov = NULL;
         g_free(p->normal);
         p->normal = NULL;
+        g_free(p->zero);
+        p->zero = NULL;
         multifd_recv_state->ops->recv_cleanup(p);
     }
     qemu_sem_destroy(&multifd_recv_state->sem_sync);
@@ -1116,13 +1135,14 @@ static void *multifd_recv_thread(void *opaque)
             break;
         }
 
-        trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->flags,
-                           p->next_packet_size);
+        trace_multifd_recv(p->id, p->packet_num, p->normal_num, p->zero_num,
+                           p->flags, p->next_packet_size);
         sync_needed = p->flags & MULTIFD_FLAG_SYNC;
         /* recv methods don't know how to handle the SYNC flag */
         p->flags &= ~MULTIFD_FLAG_SYNC;
         p->num_packets++;
         p->total_normal_pages += p->normal_num;
+        p->total_normal_pages += p->zero_num;
         qemu_mutex_unlock(&p->mutex);
 
         if (p->normal_num) {
@@ -1147,7 +1167,8 @@ static void *multifd_recv_thread(void *opaque)
     qemu_mutex_unlock(&p->mutex);
 
     rcu_unregister_thread();
-    trace_multifd_recv_thread_end(p->id, p->num_packets, p->total_normal_pages);
+    trace_multifd_recv_thread_end(p->id, p->num_packets, p->total_normal_pages,
+                                  p->total_zero_pages);
 
     return NULL;
 }
@@ -1187,6 +1208,7 @@ int multifd_load_setup(Error **errp)
         p->normal = g_new0(ram_addr_t, page_count);
         p->page_count = page_count;
         p->page_size = qemu_target_page_size();
+        p->zero = g_new0(ram_addr_t, page_count);
     }
 
     for (i = 0; i < thread_count; i++) {
diff --git a/migration/ram.c b/migration/ram.c
index 291ba5c0ed..2af70f517a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1412,8 +1412,6 @@ static int ram_save_multifd_page(RAMState *rs, RAMBlock *block,
     if (multifd_queue_page(rs->f, block, offset) < 0) {
         return -1;
     }
-    ram_counters.normal++;
-
     return 1;
 }
 
diff --git a/migration/trace-events b/migration/trace-events
index a34afe7b85..d34aec177c 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -120,21 +120,21 @@ postcopy_preempt_reset_channel(void) ""
 
 # multifd.c
 multifd_new_send_channel_async(uint8_t id) "channel %u"
-multifd_recv(uint8_t id, uint64_t packet_num, uint32_t used, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " pages %u flags 0x%x next packet size %u"
+multifd_recv(uint8_t id, uint64_t packet_num, uint32_t normal, uint32_t zero, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " normal pages %u zero pages %u flags 0x%x next packet size %u"
 multifd_recv_new_channel(uint8_t id) "channel %u"
 multifd_recv_sync_main(long packet_num) "packet num %ld"
 multifd_recv_sync_main_signal(uint8_t id) "channel %u"
 multifd_recv_sync_main_wait(uint8_t id) "channel %u"
 multifd_recv_terminate_threads(bool error) "error %d"
-multifd_recv_thread_end(uint8_t id, uint64_t packets, uint64_t pages) "channel %u packets %" PRIu64 " pages %" PRIu64
+multifd_recv_thread_end(uint8_t id, uint64_t packets, uint64_t normal_pages, uint64_t zero_pages) "channel %u packets %" PRIu64 " normal pages %" PRIu64 " zero pages %" PRIu64
 multifd_recv_thread_start(uint8_t id) "%u"
-multifd_send(uint8_t id, uint64_t packet_num, uint32_t normal, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " normal pages %u flags 0x%x next packet size %u"
+multifd_send(uint8_t id, uint64_t packet_num, uint32_t normalpages, uint32_t zero_pages, uint32_t flags, uint32_t next_packet_size) "channel %u packet_num %" PRIu64 " normal pages %u zero pages %u flags 0x%x next packet size %u"
 multifd_send_error(uint8_t id) "channel %u"
 multifd_send_sync_main(long packet_num) "packet num %ld"
 multifd_send_sync_main_signal(uint8_t id) "channel %u"
 multifd_send_sync_main_wait(uint8_t id) "channel %u"
 multifd_send_terminate_threads(bool error) "error %d"
-multifd_send_thread_end(uint8_t id, uint64_t packets, uint64_t normal_pages) "channel %u packets %" PRIu64 " normal pages %"  PRIu64
+multifd_send_thread_end(uint8_t id, uint64_t packets, uint64_t normal_pages, uint64_t zero_pages) "channel %u packets %" PRIu64 " normal pages %"  PRIu64 " zero pages %"  PRIu64
 multifd_send_thread_start(uint8_t id) "%u"
 multifd_tls_outgoing_handshake_start(void *ioc, void *tioc, const char *hostname) "ioc=%p tioc=%p hostname=%s"
 multifd_tls_outgoing_handshake_error(void *ioc, const char *err) "ioc=%p err=%s"
-- 
2.37.1