migration/multifd: Support incoming mapped-ram stream format

For the incoming mapped-ram migration we need to read the ramblock
headers, get the pages bitmap and send the host address of each
non-zero page to the multifd channel thread for writing.

Usage on HMP is:

(qemu) migrate_set_capability multifd on
(qemu) migrate_set_capability mapped-ram on
(qemu) migrate_incoming file:migfile

(the ram.h include needs to move because we've been previously relying
on it being included from migration.c. Now file.h will start including
multifd.h before migration.o is processed)

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240229153017.2221-22-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/migration/file.c b/migration/file.c
index d949a941d0..499d2782fe 100644
--- a/migration/file.c
+++ b/migration/file.c
@@ -13,7 +13,6 @@
 #include "channel.h"
 #include "file.h"
 #include "migration.h"
-#include "multifd.h"
 #include "io/channel-file.h"
 #include "io/channel-util.h"
 #include "options.h"
@@ -204,3 +203,20 @@ int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov,
 
     return (ret < 0) ? ret : 0;
 }
+
+int multifd_file_recv_data(MultiFDRecvParams *p, Error **errp)
+{
+    MultiFDRecvData *data = p->data;
+    size_t ret;
+
+    ret = qio_channel_pread(p->c, (char *) data->opaque,
+                            data->size, data->file_offset, errp);
+    if (ret != data->size) {
+        error_prepend(errp,
+                      "multifd recv (%u): read 0x%zx, expected 0x%zx",
+                      p->id, ret, data->size);
+        return -1;
+    }
+
+    return 0;
+}