Add support for sending a pagefault event if userfaultfd is registered. Only page missing event is currently supported.
Signed-off-by: Nikita Kalyazin kalyazin@amazon.com --- 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: