diff options
| author | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2017-02-24 18:28:36 +0000 |
|---|---|---|
| committer | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2017-02-28 11:30:23 +0000 |
| commit | 41d84210d403a686052fb5fc4c9f027e13e92185 (patch) | |
| tree | 2d31a0130c4b60b9e0a2dece43d16b43e1de32bc /migration | |
| parent | df9ff5e1e37982e666216fe9a324d118a30f178f (diff) | |
postcopy: Use temporary for placing zero huge pages
The kernel can't do UFFDIO_ZEROPAGE for huge pages, so we have
to allocate a temporary (always zero) page and use UFFDIO_COPYPAGE
on it.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20170224182844.32452-9-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'migration')
| -rw-r--r-- | migration/postcopy-ram.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index a8b7fedc99..4c736d28a0 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -324,6 +324,10 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) munmap(mis->postcopy_tmp_page, mis->largest_page_size); mis->postcopy_tmp_page = NULL; } + if (mis->postcopy_tmp_zero_page) { + munmap(mis->postcopy_tmp_zero_page, mis->largest_page_size); + mis->postcopy_tmp_zero_page = NULL; + } trace_postcopy_ram_incoming_cleanup_exit(); return 0; } @@ -593,8 +597,23 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host, return -e; } } else { - /* TODO: The kernel can't use UFFDIO_ZEROPAGE for hugepages */ - assert(0); + /* The kernel can't use UFFDIO_ZEROPAGE for hugepages */ + if (!mis->postcopy_tmp_zero_page) { + mis->postcopy_tmp_zero_page = mmap(NULL, mis->largest_page_size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + -1, 0); + if (mis->postcopy_tmp_zero_page == MAP_FAILED) { + int e = errno; + mis->postcopy_tmp_zero_page = NULL; + error_report("%s: %s mapping large zero page", + __func__, strerror(e)); + return -e; + } + memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size); + } + return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page, + pagesize); } return 0; |