[PATCH 4/7] KVM: Notify the state change event during shared/private conversion

Chenyi Qiang
2024-12-13T07:09:28Z

Introduce a helper to trigger the state_change() callback of the class.
Once exit to userspace to convert the page from private to shared or
vice versa at runtime, notify the event via the 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 | 4 ++++
include/sysemu/guest-memfd-manager.h | 15 +++++++++++++++
2 files changed, 19 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 52425af534..38f41a98a5 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"
@@ -3080,6 +3081,9 @@ 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);

+ guest_memfd_manager_state_change(GUEST_MEMFD_MANAGER(mr->rdm), offset,
+ size, to_private);
+
if (to_private) {
if (rb->page_size != qemu_real_host_page_size()) {
/*
diff --git a/include/sysemu/guest-memfd-manager.h b/include/sysemu/guest-memfd-manager.h
index f4b175529b..9dc4e0346d 100644
--- a/include/sysemu/guest-memfd-manager.h
+++ b/include/sysemu/guest-memfd-manager.h
@@ -46,4 +46,19 @@ struct GuestMemfdManagerClass {
bool shared_to_private);
};

+static inline int guest_memfd_manager_state_change(GuestMemfdManager *gmm, uint64_t offset,
+ uint64_t size, bool shared_to_private)
+{
+ GuestMemfdManagerClass *klass;
+
+ g_assert(gmm);
+ klass = GUEST_MEMFD_MANAGER_GET_CLASS(gmm);
+
+ if (klass->state_change) {
+ return klass->state_change(gmm, offset, size, shared_to_private);
+ }
+
+ return 0;
+}
+
#endif
--
2.43.5