[RFC,v2,12/21] kvm/memory: Introduce the infrastructure to set the default shared/private value

Commit Message

Xiaoyao Li Sept. 14, 2023, 3:51 a.m. UTC

Introduce new flag RAM_DEFAULT_PRIVATE for RAMBlock. It's used to
indicate the default attribute,  private or not.

Set the RAM range to private explicitly when it's default private.

Originated-from: Isaku Yamahata <[e-mail]>
Signed-off-by: Xiaoyao Li <[e-mail]>
---
 accel/kvm/kvm-all.c   | 10 ++++++++++
 include/exec/memory.h |  6 ++++++
 softmmu/memory.c      | 13 +++++++++++++
 3 files changed, 29 insertions(+)

Patch

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index eeccc6317fa9..7e32ee83b258 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1487,6 +1487,16 @@  static void kvm_set_phys_mem(KVMMemoryListener *kml,
                     strerror(-err));
             abort();
         }
+
+        if (memory_region_is_default_private(mr)) {
+            err = kvm_set_memory_attributes_private(start_addr, slot_size);
+            if (err) {
+                error_report("%s: failed to set memory attribute private: %s\n",
+                             __func__, strerror(-err));
+                exit(1);
+            }
+        }
+
         start_addr += slot_size;
         ram_start_offset += slot_size;
         ram += slot_size;
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 4b8486ca3632..2c738b5dc420 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -238,6 +238,9 @@  typedef struct IOMMUTLBEvent {
 /* RAM can be private that has kvm gmem backend */
 #define RAM_KVM_GMEM    (1 << 10)
 
+/* RAM is default private */
+#define RAM_DEFAULT_PRIVATE     (1 << 11)
+
 static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
                                        IOMMUNotifierFlag flags,
                                        hwaddr start, hwaddr end,
@@ -1684,6 +1687,9 @@  bool memory_region_is_protected(MemoryRegion *mr);
  */
 bool memory_region_has_gmem_fd(MemoryRegion *mr);
 
+void memory_region_set_default_private(MemoryRegion *mr);
+bool memory_region_is_default_private(MemoryRegion *mr);
+
 /**
  * memory_region_get_iommu: check whether a memory region is an iommu
  *
diff --git a/softmmu/memory.c b/softmmu/memory.c
index e69a5f96d5d1..dc5d0d7703b5 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -1851,6 +1851,19 @@  bool memory_region_has_gmem_fd(MemoryRegion *mr)
     return mr->ram_block && mr->ram_block->gmem_fd >= 0;
 }
 
+bool memory_region_is_default_private(MemoryRegion *mr)
+{
+    return memory_region_has_gmem_fd(mr) &&
+           (mr->ram_block->flags & RAM_DEFAULT_PRIVATE);
+}
+
+void memory_region_set_default_private(MemoryRegion *mr)
+{
+    if (memory_region_has_gmem_fd(mr)) {
+        mr->ram_block->flags |= RAM_DEFAULT_PRIVATE;
+    }
+}
+
 uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
 {
     uint8_t mask = mr->dirty_log_mask;