Re: [PATCH 2/6] xenbus: Use grant-table wrapper functions

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Thu, Oct 20, 2011 at 11:35:53AM -0400, Daniel De Graaf wrote:
> The gnttab_set_{map,unmap}_op functions should be used instead of
> directly populating the fields of gnttab_map_grant_ref.

You could also mention that this has the side effect that under HVM, this happens
automatically:

 op->host_addr = __pa(vaddr);

while under PV it is unchanged.

> 
> Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
> ---
>  drivers/xen/xenbus/xenbus_client.c |   17 +++++++----------
>  1 files changed, 7 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
> index 534e744..ca7c287 100644
> --- a/drivers/xen/xenbus/xenbus_client.c
> +++ b/drivers/xen/xenbus/xenbus_client.c
> @@ -544,12 +544,10 @@ EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
>  int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
>  		    grant_handle_t *handle, void *vaddr)
>  {
> -	struct gnttab_map_grant_ref op = {
> -		.host_addr = (unsigned long)vaddr,
> -		.flags     = GNTMAP_host_map,
> -		.ref       = gnt_ref,
> -		.dom       = dev->otherend_id,
> -	};
> +	struct gnttab_map_grant_ref op;
> +
> +	gnttab_set_map_op(&op, (phys_addr_t)vaddr, GNTMAP_host_map, gnt_ref,
> +	                  dev->otherend_id);
>  
>  	if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
>  		BUG();
> @@ -674,10 +672,9 @@ EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
>  int xenbus_unmap_ring(struct xenbus_device *dev,
>  		      grant_handle_t handle, void *vaddr)
>  {
> -	struct gnttab_unmap_grant_ref op = {
> -		.host_addr = (unsigned long)vaddr,
> -		.handle    = handle,
> -	};
> +	struct gnttab_unmap_grant_ref op;
> +
> +	gnttab_set_unmap_op(&op, (phys_addr_t)vaddr, GNTMAP_host_map, handle);
>  
>  	if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
>  		BUG();
> -- 
> 1.7.6.4