Re: [Xen-devel] [PATCH v1] xen: fix HYPERVISOR_dm_op() prototype

[Jan Beulich]

>>> On 05.06.17 at 10:41, <sergey.dyasli@xxxxxxxxxx> wrote:
> --- a/arch/x86/include/asm/xen/hypercall.h
> +++ b/arch/x86/include/asm/xen/hypercall.h
> @@ -49,6 +49,7 @@
>  #include <xen/interface/physdev.h>
>  #include <xen/interface/platform.h>
>  #include <xen/interface/xen-mca.h>
> +#include <xen/interface/hvm/dm_op.h>

Why?

> @@ -474,7 +475,7 @@ HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
>  
>  static inline int
>  HYPERVISOR_dm_op(
> -	domid_t dom, unsigned int nr_bufs, void *bufs)
> +	domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)

All you need above here is a forward declaration of the structure.
We should really avoid forcing source files to include all sorts of
headers without actually needing anything from them.

> --- a/include/xen/arm/hypercall.h
> +++ b/include/xen/arm/hypercall.h
> @@ -38,6 +38,7 @@
>  #include <xen/interface/xen.h>
>  #include <xen/interface/sched.h>
>  #include <xen/interface/platform.h>
> +#include <xen/interface/hvm/dm_op.h>

Same here.

> @@ -53,7 +54,8 @@ int HYPERVISOR_physdev_op(int cmd, void *arg);
>  int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args);
>  int HYPERVISOR_tmem_op(void *arg);
>  int HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type);
> -int HYPERVISOR_dm_op(domid_t domid, unsigned int nr_bufs, void *bufs);
> +int HYPERVISOR_dm_op(domid_t domid, unsigned int nr_bufs,
> +		     struct xen_dm_op_buf *bufs);

How come you get away with changing a declaration without
also changing the matching definition?

Jan