hw/mem/cxl_type3: Fix problem with g_steal_pointer()

When setting GLIB_VERSION_MAX_ALLOWED to GLIB_VERSION_2_58 or higher,
glib adds type safety checks to the g_steal_pointer() macro. This
triggers errors in the ct3_build_cdat_entries_for_mr() function which
uses the g_steal_pointer() for type-casting from one pointer type to
the other (which also looks quite weird since the local pointers have
all been declared with g_autofree though they are never freed here).
Fix it by using a proper typecast instead. For making this possible, we
have to remove the QEMU_PACKED attribute from some structs since GCC
otherwise complains that the source and destination pointer might
have different alignment restrictions. Removing the QEMU_PACKED should
be fine here since the structs are already naturally aligned. Anyway,
add some QEMU_BUILD_BUG_ON() statements to make sure that we've got
the right sizes (without padding in the structs).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/mem/cxl_type3.c

@@ -46,12 +46,12 @@ static void ct3_build_cdat_entries_for_mr(CDATSubHeader **cdat_table,
                                           int dsmad_handle, MemoryRegion *mr,
                                           bool is_pmem, uint64_t dpa_base)
 {
-    g_autofree CDATDsmas *dsmas = NULL;
-    g_autofree CDATDslbis *dslbis0 = NULL;
-    g_autofree CDATDslbis *dslbis1 = NULL;
-    g_autofree CDATDslbis *dslbis2 = NULL;
-    g_autofree CDATDslbis *dslbis3 = NULL;
-    g_autofree CDATDsemts *dsemts = NULL;
+    CDATDsmas *dsmas;
+    CDATDslbis *dslbis0;
+    CDATDslbis *dslbis1;
+    CDATDslbis *dslbis2;
+    CDATDslbis *dslbis3;
+    CDATDsemts *dsemts;
 
     dsmas = g_malloc(sizeof(*dsmas));
     *dsmas = (CDATDsmas) {
@@ -135,12 +135,12 @@ static void ct3_build_cdat_entries_for_mr(CDATSubHeader **cdat_table,
     };
 
     /* Header always at start of structure */
-    cdat_table[CT3_CDAT_DSMAS] = g_steal_pointer(&dsmas);
-    cdat_table[CT3_CDAT_DSLBIS0] = g_steal_pointer(&dslbis0);
-    cdat_table[CT3_CDAT_DSLBIS1] = g_steal_pointer(&dslbis1);
-    cdat_table[CT3_CDAT_DSLBIS2] = g_steal_pointer(&dslbis2);
-    cdat_table[CT3_CDAT_DSLBIS3] = g_steal_pointer(&dslbis3);
-    cdat_table[CT3_CDAT_DSEMTS] = g_steal_pointer(&dsemts);
+    cdat_table[CT3_CDAT_DSMAS] = (CDATSubHeader *)dsmas;
+    cdat_table[CT3_CDAT_DSLBIS0] = (CDATSubHeader *)dslbis0;
+    cdat_table[CT3_CDAT_DSLBIS1] = (CDATSubHeader *)dslbis1;
+    cdat_table[CT3_CDAT_DSLBIS2] = (CDATSubHeader *)dslbis2;
+    cdat_table[CT3_CDAT_DSLBIS3] = (CDATSubHeader *)dslbis3;
+    cdat_table[CT3_CDAT_DSEMTS] = (CDATSubHeader *)dsemts;
 }
 
 static int ct3_build_cdat_table(CDATSubHeader ***cdat_table, void *priv)

include/hw/cxl/cxl_cdat.h

@@ -82,7 +82,8 @@ typedef struct CDATDsmas {
     uint16_t reserved;
     uint64_t DPA_base;
     uint64_t DPA_length;
-} QEMU_PACKED CDATDsmas;
+} CDATDsmas;
+QEMU_BUILD_BUG_ON(sizeof(CDATDsmas) != 24);
 
 /* Device Scoped Latency and Bandwidth Information Structure - CDAT Table 5 */
 typedef struct CDATDslbis {
@@ -95,7 +96,8 @@ typedef struct CDATDslbis {
     uint64_t entry_base_unit;
     uint16_t entry[3];
     uint16_t reserved2;
-} QEMU_PACKED CDATDslbis;
+} CDATDslbis;
+QEMU_BUILD_BUG_ON(sizeof(CDATDslbis) != 24);
 
 /* Device Scoped Memory Side Cache Information Structure - CDAT Table 6 */
 typedef struct CDATDsmscis {
@@ -122,7 +124,8 @@ typedef struct CDATDsemts {
     uint16_t reserved;
     uint64_t DPA_offset;
     uint64_t DPA_length;
-} QEMU_PACKED CDATDsemts;
+} CDATDsemts;
+QEMU_BUILD_BUG_ON(sizeof(CDATDsemts) != 24);
 
 /* Switch Scoped Latency and Bandwidth Information Structure - CDAT Table 9 */
 typedef struct CDATSslbisHeader {