Memory of a KVM_X86_SW_PROTECTED_VM defaults to faultable to align with the default in kvm->mem_attr_array.
For this RFC, determine default faultability when associating a range with a memslot.
Another option is to determine default faultability at guest_memfd creation time. guest_memfd is created for a specific VM, hence we can set default faultability based on the VM type.
In future, if different struct kvms are bound to the same guest_memfd inode, all the struct kvms must be of the same vm_type.
TODO: Perhaps faultability should be based on kvm->mem_attr_array?
Signed-off-by: Ackerley Tng ackerleytng@google.com
--- virt/kvm/guest_memfd.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index fc2483e35876..1d4dfe0660ad 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -1256,6 +1256,23 @@ static struct file *kvm_gmem_inode_create_getfile(void *priv, loff_t size, return file; }
+static void kvm_gmem_set_default_faultability_by_vm_type(struct inode *inode, + u8 vm_type, + loff_t start, loff_t end) +{ + bool faultable; + + switch (vm_type) { + case KVM_X86_SW_PROTECTED_VM: + faultable = true; + break; + default: + faultable = false; + } + + WARN_ON(kvm_gmem_set_faultable(inode, start, end, faultable)); +} + static int __kvm_gmem_create(struct kvm *kvm, loff_t size, u64 flags) { struct kvm_gmem *gmem; @@ -1378,6 +1395,11 @@ int kvm_gmem_bind(struct kvm *kvm, struct kvm_memory_slot *slot, slot->gmem.pgoff = start;
xa_store_range(&gmem->bindings, start, end - 1, slot, GFP_KERNEL); + + kvm_gmem_set_default_faultability_by_vm_type(file_inode(file), + kvm->arch.vm_type, + start, end); + filemap_invalidate_unlock(inode->i_mapping);
/*