Commit c53b7ddc authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Juan Quintela
Browse files

postcopy: Check order of received target pages 



Ensure that target pages received within a host page are in order.
This shouldn't trigger, but in the cases where the sender goes
wrong and sends stuff out of order it produces a corruption that's
really nasty to debug.

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent a7180877

migration/ram.c

+11 −0
Original line number Diff line number Diff line
@@ -2097,6 +2097,7 @@ static int ram_load_postcopy(QEMUFile *f) 
    MigrationIncomingState *mis = migration_incoming_get_current();

    /* Temporary page that is later 'placed' */

    void *postcopy_host_page = postcopy_get_tmp_page(mis);

    void *last_host = NULL;



    while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {

        ram_addr_t addr;
@@ -2133,7 +2134,16 @@ static int ram_load_postcopy(QEMUFile *f) 
            /* If all TP are zero then we can optimise the place */

            if (!((uintptr_t)host & ~qemu_host_page_mask)) {

                all_zero = true;

            } else {

                /* not the 1st TP within the HP */

                if (host != (last_host + TARGET_PAGE_SIZE)) {

                    error_report("Non-sequential target page %p/%p\n",

                                  host, last_host);

                    ret = -EINVAL;

                    break;

                }

            }





            /*

             * If it's the last part of a host page then we place the host
@@ -2143,6 +2153,7 @@ static int ram_load_postcopy(QEMUFile *f) 
                                     ~qemu_host_page_mask) == 0;

            place_source = postcopy_host_page;

        }

        last_host = host;



        switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {

        case RAM_SAVE_FLAG_COMPRESS: