postcopy: Mask fault addresses to huge page boundary

Currently the fault address received by userfault is rounded to
the host page boundary and a host page is requested from the source.
Use the current RAMBlock page size instead of the general host page
size so that for RAMBlocks backed by huge pages we request the whole
huge page.

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: <20170224182844.32452-11-dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 4c736d28a0fdb408991e97322dd00555e60717c0..03cbd6e697487c574396641da3f1da8d754ee5e4 100644 (file)
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -403,7 +403,6 @@ static void *postcopy_ram_fault_thread(void *opaque)
     MigrationIncomingState *mis = opaque;
     struct uffd_msg msg;
     int ret;
-    size_t hostpagesize = getpagesize();
     RAMBlock *rb = NULL;
     RAMBlock *last_rb = NULL; /* last RAMBlock we sent part of */
 
@@ -470,7 +469,7 @@ static void *postcopy_ram_fault_thread(void *opaque)
             break;
         }
 
-        rb_offset &= ~(hostpagesize - 1);
+        rb_offset &= ~(qemu_ram_pagesize(rb) - 1);
         trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address,
                                                 qemu_ram_get_idstr(rb),
                                                 rb_offset);
@@ -482,11 +481,11 @@ static void *postcopy_ram_fault_thread(void *opaque)
         if (rb != last_rb) {
             last_rb = rb;
             migrate_send_rp_req_pages(mis, qemu_ram_get_idstr(rb),
-                                     rb_offset, hostpagesize);
+                                     rb_offset, qemu_ram_pagesize(rb));
         } else {
             /* Save some space */
             migrate_send_rp_req_pages(mis, NULL,
-                                     rb_offset, hostpagesize);
+                                     rb_offset, qemu_ram_pagesize(rb));
         }
     }
     trace_postcopy_ram_fault_thread_exit();