[PATCH V9 02/46] memory: RAM_NAMED_FILE flag

[Steve Sistare <steven.sistare@oracle.com>]

A memory-backend-ram or a memory-backend-memfd block with the RAM_SHARED
flag set is not migrated when migrate_ignore_shared() is true, but this
is wrong, because it has no named backing store, and its contents will be
lost.  Define a new flag RAM_NAMED_FILE to distinguish this case.  Cpr will
also test this flag, for similar reasons.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 backends/hostmem-file.c | 1 +
 include/exec/memory.h   | 3 +++
 include/exec/ram_addr.h | 1 +
 migration/ram.c         | 3 ++-
 softmmu/physmem.c       | 7 ++++++-
 5 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 2514128..486d77d 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -56,6 +56,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
     ram_flags = backend->share ? RAM_SHARED : 0;
     ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
     ram_flags |= fb->is_pmem ? RAM_PMEM : 0;
+    ram_flags |= RAM_NAMED_FILE;
     memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name,
                                      backend->size, fb->align, ram_flags,
                                      fb->mem_path, fb->readonly, errp);
diff --git a/include/exec/memory.h b/include/exec/memory.h
index bfb1de8..7513d04 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -206,6 +206,9 @@ typedef struct IOMMUTLBEvent {
 /* RAM that isn't accessible through normal means. */
 #define RAM_PROTECTED (1 << 8)
 
+/* RAM is an mmap-ed named file */
+#define RAM_NAMED_FILE (1 << 9)
+
 static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
                                        IOMMUNotifierFlag flags,
                                        hwaddr start, hwaddr end,
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index f3e0c78..4405e2e 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -94,6 +94,7 @@ static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
 }
 
 bool ramblock_is_pmem(RAMBlock *rb);
+bool ramblock_is_named_file(RAMBlock *rb);
 
 long qemu_minrampagesize(void);
 long qemu_maxrampagesize(void);
diff --git a/migration/ram.c b/migration/ram.c
index b94669b..3ea3b41 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -165,7 +165,8 @@ out:
 bool ramblock_is_ignored(RAMBlock *block)
 {
     return !qemu_ram_is_migratable(block) ||
-           (migrate_ignore_shared() && qemu_ram_is_shared(block));
+           (migrate_ignore_shared() && qemu_ram_is_shared(block) &&
+            ramblock_is_named_file(block));
 }
 
 #undef RAMBLOCK_FOREACH
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index dc3c3e5..cce721a 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2070,7 +2070,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
 
     /* Just support these ram flags by now. */
     assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE |
-                          RAM_PROTECTED)) == 0);
+                          RAM_PROTECTED | RAM_NAMED_FILE)) == 0);
 
     if (xen_enabled()) {
         error_setg(errp, "-mem-path not supported with Xen");
@@ -3675,6 +3675,11 @@ bool ramblock_is_pmem(RAMBlock *rb)
     return rb->flags & RAM_PMEM;
 }
 
+bool ramblock_is_named_file(RAMBlock *rb)
+{
+    return rb->flags & RAM_NAMED_FILE;
+}
+
 static void mtree_print_phys_entries(int start, int end, int skip, int ptr)
 {
     if (start == end - 1) {
-- 
1.8.3.1