[Qemu-devel] [PATCH v3 1/2] memory: export migration page size

["Michael S. Tsirkin" <mst@redhat.com>]

Migration code assumes that each RAM block is a multiple of target page
size.
We can fix this in a variety of ways, the simplest way is
exporting the required page size so callers can make regions
large enough.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 arch_init.c           | 6 ++++++
 include/exec/memory.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/arch_init.c b/arch_init.c
index 68a7ab7..c62778f 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -150,6 +150,12 @@ int qemu_read_default_config_files(bool userconfig)
     return 0;
 }
 
+/* Smallest page size for migrated RAM. */
+uint64_t qemu_migration_page_size(void)
+{
+    return TARGET_PAGE_SIZE;
+}
+
 static inline bool is_zero_page(uint8_t *p)
 {
     return buffer_find_nonzero_offset(p, TARGET_PAGE_SIZE) ==
diff --git a/include/exec/memory.h b/include/exec/memory.h
index ebe0d24..6ffffa2 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -1055,6 +1055,7 @@ void *address_space_map(AddressSpace *as, hwaddr addr,
 void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
                          int is_write, hwaddr access_len);
 
+extern uint64_t qemu_migration_page_size(void);
 
 #endif
 
-- 
MST