diff options
| author | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2018-03-12 17:20:58 +0000 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2018-03-20 05:03:27 +0200 |
| commit | 2ce16640b4cc9ab9e7e6bde9e4264b102e0eb73d (patch) | |
| tree | d35a0ed702eaf057ffbd886db9c54d911ee2dd76 /migration | |
| parent | f90bb71bfdaca6ece1696e194aad11fb8599ffba (diff) | |
postcopy: use UFFDIO_ZEROPAGE only when available
Use a flag on the RAMBlock to state whether it has the
UFFDIO_ZEROPAGE capability, use it when it's available.
This allows the use of postcopy on tmpfs as well as hugepage
backed files.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'migration')
| -rw-r--r-- | migration/postcopy-ram.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 032abfbf1a..a75b5d393f 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -481,6 +481,10 @@ static int ram_block_enable_notify(const char *block_name, void *host_addr, error_report("%s userfault: Region doesn't support COPY", __func__); return -1; } + if (reg_struct.ioctls & ((__u64)1 << _UFFDIO_ZEROPAGE)) { + RAMBlock *rb = qemu_ram_block_by_name(block_name); + qemu_ram_set_uf_zeroable(rb); + } return 0; } @@ -700,11 +704,14 @@ int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from, int postcopy_place_page_zero(MigrationIncomingState *mis, void *host, RAMBlock *rb) { + size_t pagesize = qemu_ram_pagesize(rb); trace_postcopy_place_page_zero(host); - if (qemu_ram_pagesize(rb) == getpagesize()) { - if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, NULL, getpagesize(), - rb)) { + /* Normal RAMBlocks can zero a page using UFFDIO_ZEROPAGE + * but it's not available for everything (e.g. hugetlbpages) + */ + if (qemu_ram_is_uf_zeroable(rb)) { + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, NULL, pagesize, rb)) { int e = errno; error_report("%s: %s zero host: %p", __func__, strerror(e), host); |