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-rw-r--r--migration/savevm.c32
1 files changed, 21 insertions, 11 deletions
diff --git a/migration/savevm.c b/migration/savevm.c
index 26d2c44b5e..3b19a4a274 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -870,7 +870,7 @@ int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len)
void qemu_savevm_send_postcopy_advise(QEMUFile *f)
{
uint64_t tmp[2];
- tmp[0] = cpu_to_be64(getpagesize());
+ tmp[0] = cpu_to_be64(ram_pagesize_summary());
tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
trace_qemu_savevm_send_postcopy_advise();
@@ -1352,7 +1352,7 @@ static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
{
PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
- uint64_t remote_hps, remote_tps;
+ uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps;
trace_loadvm_postcopy_handle_advise();
if (ps != POSTCOPY_INCOMING_NONE) {
@@ -1365,17 +1365,27 @@ static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
return -1;
}
- remote_hps = qemu_get_be64(mis->from_src_file);
- if (remote_hps != getpagesize()) {
+ remote_pagesize_summary = qemu_get_be64(mis->from_src_file);
+ local_pagesize_summary = ram_pagesize_summary();
+
+ if (remote_pagesize_summary != local_pagesize_summary) {
/*
- * Some combinations of mismatch are probably possible but it gets
- * a bit more complicated. In particular we need to place whole
- * host pages on the dest at once, and we need to ensure that we
- * handle dirtying to make sure we never end up sending part of
- * a hostpage on it's own.
+ * This detects two potential causes of mismatch:
+ * a) A mismatch in host page sizes
+ * Some combinations of mismatch are probably possible but it gets
+ * a bit more complicated. In particular we need to place whole
+ * host pages on the dest at once, and we need to ensure that we
+ * handle dirtying to make sure we never end up sending part of
+ * a hostpage on it's own.
+ * b) The use of different huge page sizes on source/destination
+ * a more fine grain test is performed during RAM block migration
+ * but this test here causes a nice early clear failure, and
+ * also fails when passed to an older qemu that doesn't
+ * do huge pages.
*/
- error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
- (int)remote_hps, getpagesize());
+ error_report("Postcopy needs matching RAM page sizes (s=%" PRIx64
+ " d=%" PRIx64 ")",
+ remote_pagesize_summary, local_pagesize_summary);
return -1;
}