Add support for sending a pagefault event if userfaultfd is registered.
Only page missing event is currently supported.
Signed-off-by: Nikita Kalyazin <kalyazin@xxxxxxxxxx>
---
virt/kvm/guest_memfd.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index af825f7494ea..358c3776ed66 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -4,6 +4,9 @@
#include <linux/kvm_host.h>
#include <linux/pagemap.h>
#include <linux/anon_inodes.h>
+#ifdef CONFIG_KVM_PRIVATE_MEM
+#include <linux/userfaultfd_k.h>
+#endif /* CONFIG_KVM_PRIVATE_MEM */
#include "kvm_mm.h"
@@ -332,9 +335,16 @@ static vm_fault_t kvm_gmem_fault(struct vm_fault *vmf)
struct folio *folio;
vm_fault_t ret = VM_FAULT_LOCKED;
+ folio = filemap_get_entry(inode->i_mapping, vmf->pgoff);
+ if (!folio && userfaultfd_missing(vmf->vma))
+ return handle_userfault(vmf, VM_UFFD_MISSING);
+ if (folio)
+ folio_lock(folio);
+
filemap_invalidate_lock_shared(inode->i_mapping);
- folio = kvm_gmem_get_folio(inode, vmf->pgoff);
+ if (!folio)
+ folio = kvm_gmem_get_folio(inode, vmf->pgoff);
if (IS_ERR(folio)) {
switch (PTR_ERR(folio)) {
case -EAGAIN:
--
2.47.1
