On Thu, Apr 04, 2024, Paolo Bonzini wrote: > In preparation for adding a function that walks a set of pages > provided by userspace and populates them in a guest_memfd, > add a version of kvm_gmem_get_pfn() that has a "bool prepare" > argument and passes it down to kvm_gmem_get_folio(). > > Populating guest memory has to call repeatedly __kvm_gmem_get_pfn() > on the same file, so make the new function take struct file*. > > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > --- > virt/kvm/guest_memfd.c | 38 +++++++++++++++++++++++--------------- > 1 file changed, 23 insertions(+), 15 deletions(-) > > diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c > index 486748e65f36..a537a7e63ab5 100644 > --- a/virt/kvm/guest_memfd.c > +++ b/virt/kvm/guest_memfd.c > @@ -540,33 +540,29 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot) > fput(file); > } > > -int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, > - gfn_t gfn, kvm_pfn_t *pfn, int *max_order) > +static int __kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot, > + gfn_t gfn, kvm_pfn_t *pfn, int *max_order, bool prepare) I genuinely don't know what it means to "prepare" a guest_memfd. I see it becomes if (!prepare) fgp_flags |= FGP_CREAT_ONLY; but I find the name "prepare" to be extremely unhelpful.
