[PATCH 13/24] xen/arm: get privilege status

[Ian Campbell]

On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:
> Use Xen features to figure out if we are privileged.
> 
> XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
> ---
>  arch/arm/xen/enlighten.c         |    7 +++++++
>  include/xen/interface/features.h |    3 +++
>  2 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index dc68074..2e013cf 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -2,6 +2,7 @@
>  #include <xen/interface/xen.h>
>  #include <xen/interface/memory.h>
>  #include <xen/platform_pci.h>
> +#include <xen/features.h>
>  #include <asm/xen/hypervisor.h>
>  #include <asm/xen/hypercall.h>
>  #include <linux/module.h>
> @@ -58,6 +59,12 @@ int __init xen_guest_init(void)
>  	}
>  	xen_domain_type = XEN_HVM_DOMAIN;
>  
> +	xen_setup_features();
> +	if (xen_feature(XENFEAT_dom0))
> +		xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
> +	else
> +		xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);

What happens here on platforms prior to hypervisor changeset 23735?

> +
>  	/* already setup */
>  	if (shared_info_page != 0 && HYPERVISOR_shared_info == shared_info_page)
>  		return 0;
> diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
> index b6ca39a..131a6cc 100644
> --- a/include/xen/interface/features.h
> +++ b/include/xen/interface/features.h
> @@ -50,6 +50,9 @@
>  /* x86: pirq can be used by HVM guests */
>  #define XENFEAT_hvm_pirqs           10
>  
> +/* operation as Dom0 is supported */
> +#define XENFEAT_dom0                      11
> +
>  #define XENFEAT_NR_SUBMAPS 1
>  
>  #endif /* __XEN_PUBLIC_FEATURES_H__ */