[RFC PATCH 3/6] KVM: Notify the state change via RamDiscardManager helper during shared/private conversion

[Chenyi Qiang <chenyi.qiang@intel.com>]

Once exit to userspace to convert the page from private to shared or
vice versa at runtime, notify the state change via the
guest_memfd_state_change() helper so that other registered subsystems
like VFIO can be notified.

Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
---
 accel/kvm/kvm-all.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 854cb86b22..94bbbbd2de 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -48,6 +48,7 @@
 #include "kvm-cpus.h"
 #include "sysemu/dirtylimit.h"
 #include "qemu/range.h"
+#include "sysemu/guest-memfd-manager.h"
 
 #include "hw/boards.h"
 #include "sysemu/stats.h"
@@ -2852,6 +2853,7 @@ int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private)
     RAMBlock *rb;
     void *addr;
     int ret = -1;
+    GuestMemfdManager *gmm;
 
     trace_kvm_convert_memory(start, size, to_private ? "shared_to_private" : "private_to_shared");
 
@@ -2914,6 +2916,11 @@ int kvm_convert_memory(hwaddr start, hwaddr size, bool to_private)
     addr = memory_region_get_ram_ptr(mr) + section.offset_within_region;
     rb = qemu_ram_block_from_host(addr, false, &offset);
 
+    gmm = GUEST_MEMFD_MANAGER(mr->rdm);
+    if (gmm) {
+        guest_memfd_state_change(gmm, offset, size, to_private);
+    }
+
     if (to_private) {
         if (rb->page_size != qemu_real_host_page_size()) {
             /*
-- 
2.43.5