softmmu/physmem: Fix qemu_ram_remap() to handle shared anonymous memory

RAM_SHARED now also properly indicates shared anonymous memory. Let's check
that flag for anonymous memory as well, to restore the proper mapping.

Fixes: 06329cce ("mem: add share parameter to memory-backend-ram")
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210406080126.24010-4-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

softmmu/physmem.c

@@ -2243,13 +2243,13 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
                 abort();
             } else {
                 flags = MAP_FIXED;
+                flags |= block->flags & RAM_SHARED ?
+                         MAP_SHARED : MAP_PRIVATE;
                 if (block->fd >= 0) {
-                    flags |= (block->flags & RAM_SHARED ?
-                              MAP_SHARED : MAP_PRIVATE);
                     area = mmap(vaddr, length, PROT_READ | PROT_WRITE,
                                 flags, block->fd, offset);
                 } else {
-                    flags |= MAP_PRIVATE | MAP_ANONYMOUS;
+                    flags |= MAP_ANONYMOUS;
                     area = mmap(vaddr, length, PROT_READ | PROT_WRITE,
                                 flags, -1, 0);
                 }