diff options
| author | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2017-05-17 17:58:09 +0100 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2017-05-18 18:04:53 +0200 |
| commit | 1eb3fc0a0b61b5d22adee2a9add3162a6c03a47e (patch) | |
| tree | f52c213e3456aa91214d9ee05db39a02213810ff /migration/ram.c | |
| parent | 56821559f0ba682fe6b367815572e6f974d329ab (diff) | |
migration: Fix non-multiple of page size migration
Unfortunately it's legal to create a VM with a RAM size that's
not a multiple of the underlying host page or huge page size.
Recently I'd changed things to always send host sized pages,
and that breaks if we have say a 1025MB guest on 2MB hugepages.
Unfortunately we can't just make that illegal since it would break
migration from/to existing oddly configured VMs.
Symptom: qemu-system-x86_64: Illegal RAM offset 40100000
as it transmits the fraction of the hugepage after the end
of the RAMBlock (may also cause a crash on the source
- possibly due to clearing bits after the bitmap)
Reported-by: Yumei Huang <yuhuang@redhat.com>
Red Hat bug: https://bugzilla.redhat.com/show_bug.cgi?id=1449037
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>
Diffstat (limited to 'migration/ram.c')
| -rw-r--r-- | migration/ram.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/migration/ram.c b/migration/ram.c index f59fdd41a4..59459efe18 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1312,6 +1312,8 @@ static int ram_save_target_page(RAMState *rs, PageSearchStatus *pss, * a host page in which case the remainder of the hostpage is sent. * Only dirty target pages are sent. Note that the host page size may * be a huge page for this block. + * The saving stops at the boundary of the used_length of the block + * if the RAMBlock isn't a multiple of the host page size. * * Returns the number of pages written or negative on error * @@ -1335,7 +1337,8 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss, pages += tmppages; pss->page++; - } while (pss->page & (pagesize_bits - 1)); + } while ((pss->page & (pagesize_bits - 1)) && + offset_in_ramblock(pss->block, pss->page << TARGET_PAGE_BITS)); /* The offset we leave with is the last one we looked at */ pss->page--; |