postcopy: Require RAMBlocks that are whole pages

It turns out that it's legal to create a VM with RAMBlocks that aren't
a multiple of the pagesize in use; e.g. a 1025M main memory using
2M host pages.  That breaks postcopy's atomic placement of pages,
so disallow it.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert 2017-05-17 17:58:10 +01:00 committed by Juan Quintela
parent 1eb3fc0a0b
commit 5d214a92ac

View File

@ -96,14 +96,24 @@ static bool ufd_version_check(int ufd)
/* Callback from postcopy_ram_supported_by_host block iterator.
*/
static int test_range_shared(const char *block_name, void *host_addr,
static int test_ramblock_postcopiable(const char *block_name, void *host_addr,
ram_addr_t offset, ram_addr_t length, void *opaque)
{
if (qemu_ram_is_shared(qemu_ram_block_by_name(block_name))) {
RAMBlock *rb = qemu_ram_block_by_name(block_name);
size_t pagesize = qemu_ram_pagesize(rb);
if (qemu_ram_is_shared(rb)) {
error_report("Postcopy on shared RAM (%s) is not yet supported",
block_name);
return 1;
}
if (length % pagesize) {
error_report("Postcopy requires RAM blocks to be a page size multiple,"
" block %s is 0x" RAM_ADDR_FMT " bytes with a "
"page size of 0x%zx", block_name, length, pagesize);
return 1;
}
return 0;
}
@ -140,7 +150,7 @@ bool postcopy_ram_supported_by_host(void)
}
/* We don't support postcopy with shared RAM yet */
if (qemu_ram_foreach_block(test_range_shared, NULL)) {
if (qemu_ram_foreach_block(test_ramblock_postcopiable, NULL)) {
goto out;
}