On 5/23/25 11:50 AM, Akihiko Odaki wrote: > On 2025/05/21 20:33, Paolo Abeni wrote: >> @@ -235,4 +235,12 @@ >> */ >> #define VHOST_VDPA_GET_VRING_SIZE _IOWR(VHOST_VIRTIO, 0x82, \ >> struct vhost_vring_state) >> + >> +/* Extended features manipulation >> + */ >> +#ifdef __SIZEOF_INT128__ >> +#define VHOST_GET_FEATURES_EX _IOR(VHOST_VIRTIO, 0x83, __u128) >> +#define VHOST_SET_FEATURES_EX _IOW(VHOST_VIRTIO, 0x83, __u128) > > Suffixing names with _EX is a culture of Windows, and it becomes mess > when extending multiple times (e.g., VHOST_GET_FEATURES_EX_EX). > > I sugguest naming them as VHOST_GET_FEATURES2 and VHOST_SET_FEATURES2 or > VHOST_GET_FEATURES128 and VHOST_SET_FEATURES128 for clarity. > > include/uapi/asm-generic/ioctl.h says: > * Encoding the size of the parameter structure in the ioctl request > * is useful for catching programs compiled with old versions > * and to avoid overwriting user space outside the user buffer area. > > So perhaps the intended encoding for an extended ioctl is to keep the > first and second argument and change only the third parameter. For example: > > #define VHOST_GET_FEATURES128 _IOR(VHOST_VIRTIO, 0x00, __u128) > #define VHOST_SET_FEATURES128 _IOW(VHOST_VIRTIO, 0x00, __u128)
Thanks, I like that the latter form. I'll do in the next revision. BTW, the reference to that legacy OS really hurts here :-P /P
