migration: Simplify alignment and alignment checks

Let's use QEMU_ALIGN_DOWN() and friends to make the code a bit easier to
read.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

3 files changed, 8 insertions, 9 deletions

diff --git a/migration/migration.c b/migration/migration.c
index e1c0082..53b9a8a 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -391,7 +391,7 @@ int migrate_send_rp_message_req_pages(MigrationIncomingState *mis,
 int migrate_send_rp_req_pages(MigrationIncomingState *mis,
                               RAMBlock *rb, ram_addr_t start, uint64_t haddr)
 {
-    void *aligned = (void *)(uintptr_t)(haddr & (-qemu_ram_pagesize(rb)));
+    void *aligned = (void *)(uintptr_t)ROUND_DOWN(haddr, qemu_ram_pagesize(rb));
     bool received = false;
 
     WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) {
@@ -2637,8 +2637,8 @@ static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname,
      * Since we currently insist on matching page sizes, just sanity check
      * we're being asked for whole host pages.
      */
-    if (start & (our_host_ps - 1) ||
-       (len & (our_host_ps - 1))) {
+    if (!QEMU_IS_ALIGNED(start, our_host_ps) ||
+        !QEMU_IS_ALIGNED(len, our_host_ps)) {
         error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT
                      " len: %zd", __func__, start, len);
         mark_source_rp_bad(ms);
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 3609ce7..e721f69 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -402,7 +402,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
                      strerror(errno));
         goto out;
     }
-    g_assert(((size_t)testarea & (pagesize - 1)) == 0);
+    g_assert(QEMU_PTR_IS_ALIGNED(testarea, pagesize));
 
     reg_struct.range.start = (uintptr_t)testarea;
     reg_struct.range.len = pagesize;
@@ -660,7 +660,7 @@ int postcopy_wake_shared(struct PostCopyFD *pcfd,
     struct uffdio_range range;
     int ret;
     trace_postcopy_wake_shared(client_addr, qemu_ram_get_idstr(rb));
-    range.start = client_addr & ~(pagesize - 1);
+    range.start = ROUND_DOWN(client_addr, pagesize);
     range.len = pagesize;
     ret = ioctl(pcfd->fd, UFFDIO_WAKE, &range);
     if (ret) {
@@ -702,8 +702,7 @@ static int postcopy_request_page(MigrationIncomingState *mis, RAMBlock *rb,
 int postcopy_request_shared_page(struct PostCopyFD *pcfd, RAMBlock *rb,
                                  uint64_t client_addr, uint64_t rb_offset)
 {
-    size_t pagesize = qemu_ram_pagesize(rb);
-    uint64_t aligned_rbo = rb_offset & ~(pagesize - 1);
+    uint64_t aligned_rbo = ROUND_DOWN(rb_offset, qemu_ram_pagesize(rb));
     MigrationIncomingState *mis = migration_incoming_get_current();
 
     trace_postcopy_request_shared_page(pcfd->idstr, qemu_ram_get_idstr(rb),
@@ -993,7 +992,7 @@ static void *postcopy_ram_fault_thread(void *opaque)
                 break;
             }
 
-            rb_offset &= ~(qemu_ram_pagesize(rb) - 1);
+            rb_offset = ROUND_DOWN(rb_offset, qemu_ram_pagesize(rb));
             trace_postcopy_ram_fault_thread_request(msg.arg.pagefault.address,
                                                 qemu_ram_get_idstr(rb),
                                                 rb_offset,
diff --git a/migration/ram.c b/migration/ram.c
index 4f629de..54df5dc 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -811,7 +811,7 @@ static void migration_clear_memory_region_dirty_bitmap(RAMBlock *rb,
     assert(shift >= 6);
 
     size = 1ULL << (TARGET_PAGE_BITS + shift);
-    start = (((ram_addr_t)page) << TARGET_PAGE_BITS) & (-size);
+    start = QEMU_ALIGN_DOWN((ram_addr_t)page << TARGET_PAGE_BITS, size);
     trace_migration_bitmap_clear_dirty(rb->idstr, start, size, page);
     memory_region_clear_dirty_bitmap(rb->mr, start, size);
 }