[PATCH v4 04/12] ramblock: Rename guest_memfd to guest_memfd_private

[Michael Roth <michael.roth@amd.com>]

From: Peter Xu <peterx@redhat.com>

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.

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
---
 accel/kvm/kvm-all.c       |  2 +-
 include/system/memory.h   |  7 ++++---
 include/system/ramblock.h |  7 ++++++-
 system/memory.c           |  2 +-
 system/physmem.c          | 33 +++++++++++++++++----------------
 5 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index bda2e25a66..3afe491242 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1729,7 +1729,7 @@ 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/include/system/memory.h b/include/system/memory.h
index 2192fc9bdc..96b0a0a444 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -1507,10 +1507,11 @@ bool memory_region_skip_iommu_map(const MemoryRegion *mr);
 void memory_region_set_skip_iommu_map(MemoryRegion *mr, bool skip);
 
 /**
- * memory_region_has_guest_memfd: check whether a memory region has guest_memfd
- *     associated
+ * memory_region_has_guest_memfd: check whether a memory region has
+ *     guest_memfd_private 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 valid guest_memfd_private
+ * assigned.
  *
  * @mr: the memory region being queried
  */
diff --git a/include/system/ramblock.h b/include/system/ramblock.h
index f0639287bf..8ed5e10710 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/system/memory.c b/system/memory.c
index 5fc36708ec..4e6d54148e 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1843,7 +1843,7 @@ void memory_region_set_skip_iommu_map(MemoryRegion *mr, bool skip)
 
 bool memory_region_has_guest_memfd(const 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(const MemoryRegion *mr)
diff --git a/system/physmem.c b/system/physmem.c
index 406338f165..b979518bf6 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -2200,7 +2200,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp)
             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) {
@@ -2210,9 +2210,9 @@ 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;
         }
@@ -2229,7 +2229,7 @@ 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;
@@ -2365,7 +2365,7 @@ 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);
@@ -2538,7 +2538,7 @@ 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;
@@ -2589,8 +2589,8 @@ static void reclaim_ramblock(RAMBlock *block)
         qemu_anon_ram_free(block->host, block->max_length);
     }
 
-    if (block->guest_memfd >= 0) {
-        close(block->guest_memfd);
+    if (block->guest_memfd_private >= 0) {
+        close(block->guest_memfd_private);
         ram_block_coordinated_discard_require(false);
     }
 
@@ -2838,12 +2838,12 @@ int ram_block_rebind(Error **errp)
 
     RAMBLOCK_FOREACH(block) {
         if (block->flags & RAM_GUEST_MEMFD) {
-            if (block->guest_memfd >= 0) {
-                close(block->guest_memfd);
+            if (block->guest_memfd_private >= 0) {
+                close(block->guest_memfd_private);
             }
-            block->guest_memfd = kvm_create_guest_memfd(block->max_length,
-                                                        0, errp);
-            if (block->guest_memfd < 0) {
+            block->guest_memfd_private = kvm_create_guest_memfd(
+                block->max_length, 0, errp);
+            if (block->guest_memfd_private < 0) {
                 qemu_mutex_unlock_ramlist();
                 return -1;
             }
@@ -4227,7 +4227,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t offset, size_t length)
         return ret;
     }
 
-    if (rb->guest_memfd >= 0) {
+    if (rb->guest_memfd_private >= 0) {
         ret = ram_block_discard_guest_memfd_range(rb, offset, length);
     }
 
@@ -4241,7 +4241,8 @@ 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) {
-- 
2.43.0