multifd: Use normal pages array on the send side

We are only sending normal pages through multifd channels.
Later on this series, we are going to also send zero pages.
We are going to detect if a page is zero or non zero in the multifd
channel thread, not on the main thread.

So we receive an array of pages page->offset[N]

And we will end with:

p->normal[N - zero_pages]
p->zero[zero_pages].

In this patch, we just copy all the pages in offset to normal.

for (i = 0; i < pages->num; i++) {
    p->narmal[p->normal_num] = pages->offset[i];
    p->normal_num++:
}

Later in the series this becomes:

for (i = 0; i < pages->num; i++) {
    if (buffer_is_zero(page->offset[i])) {
        p->zerol[p->zero_num] = pages->offset[i];
        p->zero_num++:
    } else {
        p->narmal[p->normal_num] = pages->offset[i];
        p->normal_num++:
    }
}

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

---

Improving comment (dave)
Renaming num_normal_pages to total_normal_pages (peter)

1 files changed, 6 insertions, 2 deletions

diff --git a/migration/multifd.h b/migration/multifd.h
index 7496f951a7..7823199dbe 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -104,14 +104,18 @@ typedef struct {
     /* thread local variables */
     /* packets sent through this channel */
     uint64_t num_packets;
-    /* pages sent through this channel */
-    uint64_t num_pages;
+    /* non zero pages sent through this channel */
+    uint64_t total_normal_pages;
     /* syncs main thread and channels */
     QemuSemaphore sem_sync;
     /* buffers to send */
     struct iovec *iov;
     /* number of iovs used */
     uint32_t iovs_num;
+    /* Pages that are not zero */
+    ram_addr_t *normal;
+    /* num of non zero pages */
+    uint32_t normal_num;
     /* used for compression methods */
     void *data;
 }  MultiFDSendParams;