From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>

Wire data commonly use BE byte order (including in the existing migration
protocol), use it also for for VFIO device state packets.

This will allow VFIO multifd device state transfer between hosts with
different endianness.
Although currently there is no such use case, it's good to have it now
for completeness.

Reviewed-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Link: https://lore.kernel.org/qemu-devel/dcfc04cc1a50655650dbac8398e2742ada84ee39.1741611079.git.maciej.szmigiero@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/vfio/migration-multifd.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c
index 233724710b377afd40aabe5ef5b846f654f9865d..378f6f3bf01f6a4155fb424f8028cb5380f27f02 100644
--- a/hw/vfio/migration-multifd.c
+++ b/hw/vfio/migration-multifd.c
@@ -13,6 +13,7 @@
 #include "hw/vfio/vfio-common.h"
 #include "migration/misc.h"
 #include "qapi/error.h"
+#include "qemu/bswap.h"
 #include "qemu/error-report.h"
 #include "qemu/lockable.h"
 #include "qemu/main-loop.h"
@@ -155,12 +156,16 @@ bool vfio_multifd_load_state_buffer(void *opaque, char *data, size_t data_size,
         return false;
     }
 
+    packet->version = be32_to_cpu(packet->version);
     if (packet->version != VFIO_DEVICE_STATE_PACKET_VER_CURRENT) {
         error_setg(errp, "%s: packet has unknown version %" PRIu32,
                    vbasedev->name, packet->version);
         return false;
     }
 
+    packet->idx = be32_to_cpu(packet->idx);
+    packet->flags = be32_to_cpu(packet->flags);
+
     if (packet->idx == UINT32_MAX) {
         error_setg(errp, "%s: packet index is invalid", vbasedev->name);
         return false;
@@ -558,9 +563,9 @@ vfio_save_complete_precopy_thread_config_state(VFIODevice *vbasedev,
 
     packet_len = sizeof(*packet) + bioc->usage;
     packet = g_malloc0(packet_len);
-    packet->version = VFIO_DEVICE_STATE_PACKET_VER_CURRENT;
-    packet->idx = idx;
-    packet->flags = VFIO_DEVICE_STATE_CONFIG_STATE;
+    packet->version = cpu_to_be32(VFIO_DEVICE_STATE_PACKET_VER_CURRENT);
+    packet->idx = cpu_to_be32(idx);
+    packet->flags = cpu_to_be32(VFIO_DEVICE_STATE_CONFIG_STATE);
     memcpy(&packet->data, bioc->data, bioc->usage);
 
     if (!multifd_queue_device_state(idstr, instance_id,
@@ -610,7 +615,7 @@ vfio_multifd_save_complete_precopy_thread(SaveLiveCompletePrecopyThreadData *d,
     }
 
     packet = g_malloc0(sizeof(*packet) + migration->data_buffer_size);
-    packet->version = VFIO_DEVICE_STATE_PACKET_VER_CURRENT;
+    packet->version = cpu_to_be32(VFIO_DEVICE_STATE_PACKET_VER_CURRENT);
 
     for (idx = 0; ; idx++) {
         ssize_t data_size;
@@ -631,7 +636,7 @@ vfio_multifd_save_complete_precopy_thread(SaveLiveCompletePrecopyThreadData *d,
             break;
         }
 
-        packet->idx = idx;
+        packet->idx = cpu_to_be32(idx);
         packet_size = sizeof(*packet) + data_size;
 
         if (!multifd_queue_device_state(d->idstr, d->instance_id,
-- 
2.48.1