Rename the field to reflect the fact that the guest_memfd in this case only
backs private portion of the ramblock rather than all of it.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/system/memory.h   |  2 +-
 include/system/ramblock.h |  7 ++++++-
 accel/kvm/kvm-all.c       |  2 +-
 system/memory.c           |  2 +-
 system/physmem.c          | 21 +++++++++++----------
 5 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index 4428701a9f..5c38018f4a 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -1826,7 +1826,7 @@ bool memory_region_is_protected(MemoryRegion *mr);
  * memory_region_has_guest_memfd_private: check whether a memory region has
  *     guest_memfd associated
  *
- * Returns %true if a memory region's ram_block has valid guest_memfd assigned.
+ * Returns %true if a memory region's ram_block has guest_memfd_private assigned.
  *
  * @mr: the memory region being queried
  */
diff --git a/include/system/ramblock.h b/include/system/ramblock.h
index 76694fe1b5..9ecf7f970c 100644
--- a/include/system/ramblock.h
+++ b/include/system/ramblock.h
@@ -40,7 +40,12 @@ struct RAMBlock {
     Error *cpr_blocker;
     int fd;
     uint64_t fd_offset;
-    int guest_memfd;
+    /*
+     * When RAM_GUEST_MEMFD_PRIVATE flag is set, this ramblock can have
+     * private pages backed by guest_memfd_private specified, while shared
+     * pages are backed by the ramblock on its own.
+     */
+    int guest_memfd_private;
     RamBlockAttributes *attributes;
     size_t page_size;
     /* dirty bitmap used during migration */
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 6521648ce9..687f33a2bb 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1598,7 +1598,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
         mem->ram_start_offset = ram_start_offset;
         mem->ram = ram;
         mem->flags = kvm_mem_flags(mr);
-        mem->guest_memfd = mr->ram_block->guest_memfd;
+        mem->guest_memfd = mr->ram_block->guest_memfd_private;
         mem->guest_memfd_offset = mem->guest_memfd >= 0 ?
                                   (uint8_t*)ram - mr->ram_block->host : 0;
 
diff --git a/system/memory.c b/system/memory.c
index 5f05e5d73e..dadcc21d0e 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1899,7 +1899,7 @@ bool memory_region_is_protected(MemoryRegion *mr)
 
 bool memory_region_has_guest_memfd_private(MemoryRegion *mr)
 {
-    return mr->ram_block && mr->ram_block->guest_memfd >= 0;
+    return mr->ram_block && mr->ram_block->guest_memfd_private >= 0;
 }
 
 uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
diff --git a/system/physmem.c b/system/physmem.c
index 1a186739a8..66fa4c7b6a 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2211,7 +2211,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
                        object_get_typename(OBJECT(current_machine->cgs)));
             goto out_free;
         }
-        assert(new_block->guest_memfd < 0);
+        assert(new_block->guest_memfd_private < 0);
 
         ret = ram_block_coordinated_discard_require(true);
         if (ret < 0) {
@@ -2221,9 +2221,9 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
             goto out_free;
         }
 
-        new_block->guest_memfd = kvm_create_guest_memfd(new_block->max_length,
-                                                        0, errp);
-        if (new_block->guest_memfd < 0) {
+        new_block->guest_memfd_private =
+            kvm_create_guest_memfd(new_block->max_length, 0, errp);
+        if (new_block->guest_memfd_private < 0) {
             qemu_mutex_unlock_ramlist();
             goto out_free;
         }
@@ -2240,7 +2240,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
         new_block->attributes = ram_block_attributes_create(new_block);
         if (!new_block->attributes) {
             error_setg(errp, "Failed to create ram block attribute");
-            close(new_block->guest_memfd);
+            close(new_block->guest_memfd_private);
             ram_block_coordinated_discard_require(false);
             qemu_mutex_unlock_ramlist();
             goto out_free;
@@ -2377,7 +2377,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, ram_addr_t max_size,
     new_block->max_length = max_size;
     new_block->resized = resized;
     new_block->flags = ram_flags;
-    new_block->guest_memfd = -1;
+    new_block->guest_memfd_private = -1;
     new_block->host = file_ram_alloc(new_block, max_size, fd,
                                      file_size < offset + max_size,
                                      offset, errp);
@@ -2550,7 +2550,7 @@ RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size,
     new_block->used_length = size;
     new_block->max_length = max_size;
     new_block->fd = -1;
-    new_block->guest_memfd = -1;
+    new_block->guest_memfd_private = -1;
     new_block->page_size = qemu_real_host_page_size();
     new_block->host = host;
     new_block->flags = ram_flags;
@@ -2601,9 +2601,9 @@ static void reclaim_ramblock(RAMBlock *block)
         qemu_anon_ram_free(block->host, block->max_length);
     }
 
-    if (block->guest_memfd >= 0) {
+    if (block->guest_memfd_private >= 0) {
         ram_block_attributes_destroy(block->attributes);
-        close(block->guest_memfd);
+        close(block->guest_memfd_private);
         ram_block_coordinated_discard_require(false);
     }
 
@@ -4211,7 +4211,8 @@ int ram_block_discard_guest_memfd_range(RAMBlock *rb, uint64_t offset,
 
 #ifdef CONFIG_FALLOCATE_PUNCH_HOLE
     /* ignore fd_offset with guest_memfd */
-    ret = fallocate(rb->guest_memfd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+    ret = fallocate(rb->guest_memfd_private,
+                    FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
                     offset, length);
 
     if (ret) {
-- 
2.50.1