@@ -30,6 +30,18 @@ int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from arch_init's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages);
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
+
+/*
* Called back from arch_init's ram_postcopy_each_ram_discard to handle
* discarding one RAMBlock's pre-postcopy dirty pages
*/
@@ -250,6 +250,93 @@ int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
return 0;
}
+/*
+ * Setup an area of RAM so that it *can* be used for postcopy later; this
+ * must be done right at the start prior to pre-copy.
+ * opaque should be the MIS.
+ */
+static int init_area(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+ MigrationIncomingState *mis = opaque;
+
+ DPRINTF("init_area: %s: %p offset=%zx length=%zd(%zx)",
+ block_name, host_addr, offset, length, length);
+ /*
+ * We need the whole of RAM to be truly empty for postcopy, so things
+ * like ROMs and any data tables built during init must be zero'd
+ * - we're going to get the copy from the source anyway.
+ */
+ if (postcopy_ram_discard_range(mis, host_addr, (host_addr + length - 1))) {
+ return -1;
+ }
+
+ /*
+ * We also need the area to be normal 4k pages, not huge pages
+ * (otherwise we can't be sure we can use remap_anon_pages to put
+ * a 4k page in later). THP might come along and map a 2MB page
+ * and when it's partially accessed in precopy it might not break
+ * it down, but leave a 2MB zero'd page.
+ */
+ if (madvise(host_addr, length, MADV_NOHUGEPAGE)) {
+ perror("init_area: NOHUGEPAGE");
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * At the end of migration, undo the effects of init_area
+ * opaque should be the MIS.
+ */
+static int cleanup_area(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+ /* Turn off userfault here as well? */
+
+ DPRINTF("cleanup_area: %s: %p offset=%zx length=%zd(%zx)",
+ block_name, host_addr, offset, length, length);
+ /*
+ * We turned off hugepage for the precopy stage with postcopy enabled
+ * we can turn it back on now.
+ */
+ if (madvise(host_addr, length, MADV_HUGEPAGE)) {
+ perror("init_area: HUGEPAGE");
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from arch_init's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+ postcopy_pmi_init(mis, ram_pages);
+
+ if (qemu_ram_foreach_block(init_area, mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
+{
+ if (qemu_ram_foreach_block(cleanup_area, mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
#else
/* No target OS support, stubs just fail */
@@ -265,6 +352,19 @@ int postcopy_ram_discard_range(MigrationIncomingState *mis, void *start,
error_report("postcopy_ram_discard_range: No OS support");
return -1;
}
+
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+ error_report("postcopy_ram_incoming_init: No OS support\n");
+ return -1;
+}
+
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
+{
+ error_report("postcopy_ram_incoming_cleanup: No OS support\n");
+ return -1;
+}
+
#endif
/* ------------------------------------------------------------------------- */