migration/postcopy: map large zero page in postcopy_ram_incoming_setup()

postcopy_ram_incoming_setup() and postcopy_ram_incoming_cleanup() are
counterpart. It is reasonable to map/unmap large zero page in these two
functions respectively.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191005135021.21721-3-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This commit is contained in:
Wei Yang 2019-10-05 21:50:21 +08:00 committed by Dr. David Alan Gilbert
parent 3414322a83
commit 6629890d55

View File

@ -1144,6 +1144,22 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis)
return -1;
}
/*
* Map large zero page when kernel can't use UFFDIO_ZEROPAGE for hugepages
*/
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: Failed to map large zero page %s",
__func__, strerror(e));
return -e;
}
memset(mis->postcopy_tmp_zero_page, '\0', mis->largest_page_size);
/*
* Ballooning can mark pages as absent while we're postcopying
* that would cause false userfaults.
@ -1250,23 +1266,7 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
qemu_ram_block_host_offset(rb,
host));
} else {
/* 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,
rb);
return postcopy_place_page(mis, host, mis->postcopy_tmp_zero_page, rb);
}
}