motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-01 06:43:53 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

postcopy: Transmit ram size summary word

Browse source 
Replace the host page-size in the 'advise' command by a pagesize
summary bitmap; if the VM is just using normal RAM then
this will be exactly the same as before, however if they're using
huge pages they'll be different, and thus:
   a) Migration from/to old qemu's that don't understand huge pages
      will fail early.
   b) Migrations with different size RAMBlocks will also fail early.

This catches it very early; earlier than the detailed per-block
check in the next patch.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20170224182844.32452-2-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Dr. David Alan Gilbert 2017-02-24 18:28:29 +00:00
parent f9c8caa04f
commit e8ca1db29b
3 changed files with 39 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

17
migration/ram.c
View file

@ -600,6 +600,23 @@ static void migration_bitmap_sync_init(void)
iterations_prev = 0;
}
/* Returns a summary bitmap of the page sizes of all RAMBlocks;
* for VMs with just normal pages this is equivalent to the
* host page size. If it's got some huge pages then it's the OR
* of all the different page sizes.
*/
uint64_t ram_pagesize_summary(void)
{
RAMBlock *block;
uint64_t summary = 0;
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
summary |= block->page_size;
}
return summary;
}
static void migration_bitmap_sync(void)
{
RAMBlock *block;