static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis) { PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE); uint64_t remote_hps, remote_tps; trace_loadvm_postcopy_handle_advise(); if (ps != POSTCOPY_INCOMING_NONE) { error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps); return -1; } if (!postcopy_ram_supported_by_host()) { postcopy_state_set(POSTCOPY_INCOMING_NONE); return -1; } remote_hps = qemu_get_be64(mis->from_src_file); if (remote_hps != getpagesize()) { /* * Some combinations of mismatch are probably possible but it gets * a bit more complicated. In particular we need to place whole * host pages on the dest at once, and we need to ensure that we * handle dirtying to make sure we never end up sending part of * a hostpage on it's own. */ error_report("Postcopy needs matching host page sizes (s=%d d=%d)", (int)remote_hps, getpagesize()); return -1; } remote_tps = qemu_get_be64(mis->from_src_file); if (remote_tps != (1ul << qemu_target_page_bits())) { /* * Again, some differences could be dealt with, but for now keep it * simple. */ error_report("Postcopy needs matching target page sizes (s=%d d=%d)", (int)remote_tps, 1 << qemu_target_page_bits()); return -1; } if (ram_postcopy_incoming_init(mis)) { return -1; } postcopy_state_set(POSTCOPY_INCOMING_ADVISE); return 0; }