Re: [PATCH v3 02/70] RAMBlock: Add support of KVM private guest memfd

[Xiaoyao Li]

On 11/18/2023 4:35 AM, Isaku Yamahata wrote:

On Wed, Nov 15, 2023 at 02:14:11AM -0500,
Xiaoyao Li <xiaoyao...@intel.com> wrote:

diff --git a/system/physmem.c b/system/physmem.c
index fc2b0fee0188..0af2213cbd9c 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1841,6 +1841,20 @@ static void ram_block_add(RAMBlock *new_block, Error 
**errp)
          }
      }

+#ifdef CONFIG_KVM

+    if (kvm_enabled() && new_block->flags & RAM_GUEST_MEMFD &&
+        new_block->guest_memfd < 0) {
+        /* TODO: to decide if KVM_GUEST_MEMFD_ALLOW_HUGEPAGE is supported */
+        uint64_t flags = 0;
+        new_block->guest_memfd = kvm_create_guest_memfd(new_block->max_length,
+                                                        flags, errp);
+        if (new_block->guest_memfd < 0) {
+            qemu_mutex_unlock_ramlist();
+            return;
+        }
+    }
+#endif
+

We should define kvm_create_guest_memfd() stub in accel/stub/kvm-stub.c.
We can remove this #ifdef.

Nice suggestion! Will use stub.