migration: Receiving a zero page non zero is an error

We don't allow non zero compressed pages since:

commit 3edcd7e6eb
Author: Peter Lieven <pl@kamp.de>
Date:   Tue Mar 26 10:58:35 2013 +0100

    migration: search for zero instead of dup pages

RDMA case is a bit more complicated, but they don't handle it since:

commit a1febc4950
Author: Richard Henderson <rth@twiddle.net>
Date:   Mon Aug 29 11:46:14 2016 -0700

    cutils: Export only buffer_is_zero

Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231019085259.13307-2-quintela@redhat.com>
This commit is contained in:
Juan Quintela 2023-10-19 10:52:58 +02:00
parent e77326179d
commit 413d64fedc
2 changed files with 16 additions and 5 deletions

View File

@ -3715,16 +3715,18 @@ int ram_load_postcopy(QEMUFile *f, int channel)
switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
case RAM_SAVE_FLAG_ZERO:
ch = qemu_get_byte(f);
if (ch != 0) {
error_report("Found a zero page with value %d", ch);
ret = -EINVAL;
break;
}
/*
* Can skip to set page_buffer when
* this is a zero page and (block->page_size == TARGET_PAGE_SIZE).
*/
if (ch || !matches_target_page_size) {
if (!matches_target_page_size) {
memset(page_buffer, ch, TARGET_PAGE_SIZE);
}
if (ch) {
tmp_page->all_zero = false;
}
break;
case RAM_SAVE_FLAG_PAGE:
@ -4030,6 +4032,11 @@ static int ram_load_precopy(QEMUFile *f)
case RAM_SAVE_FLAG_ZERO:
ch = qemu_get_byte(f);
if (ch != 0) {
error_report("Found a zero page with value %d", ch);
ret = -EINVAL;
break;
}
ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
break;

View File

@ -3592,7 +3592,11 @@ int rdma_registration_handle(QEMUFile *f)
host_addr = block->local_host_addr +
(comp->offset - block->offset);
if (comp->value) {
error_report("rdma: Zero page with non-zero (%d) value",
comp->value);
goto err;
}
ram_handle_compressed(host_addr, comp->value, comp->length);
break;