Re: [Xen-devel] [PATCH WIP 3/6] xen/arm: get privilege status

From: Konrad Rzeszutek Wilk
Date: Mon Jul 09 2012 - 10:49:51 EST


On Fri, Jun 22, 2012 at 05:14:42PM +0100, Stefano Stabellini wrote:
> Use Xen features to figure out if we are privileged.

Is there a corresponding Xen c/s for the XNEFEAT_dom0?

Why can't the existing SIF_PRIVILIGED call work? Isn't that
somethign that the hypervisor sets for the guest?

>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> ---
> arch/arm/xen/enlighten.c | 9 ++++++++-
> include/xen/interface/features.h | 3 +++
> 2 files changed, 11 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index e1c2e4d..ddacecf 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -3,6 +3,7 @@
> #include <xen/interface/memory.h>
> #include <asm/xen/hypervisor.h>
> #include <asm/xen/hypercall.h>
> +#include <xen/features.h>
>
> #include <linux/module.h>
>
> @@ -11,7 +12,7 @@
>
> #include <asm/pgtable.h>
>
> -struct start_info _xen_start_info = { .flags = (SIF_INITDOMAIN|SIF_PRIVILEGED) };
> +struct start_info _xen_start_info;
> struct start_info *xen_start_info = &_xen_start_info;
> EXPORT_SYMBOL_GPL(xen_start_info);
>
> @@ -133,6 +134,12 @@ static void __init xen_hvm_init_shared_info(void)
> struct xen_add_to_physmap xatp;
> static struct shared_info *shared_info_page = 0;
>
> + 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);
> +
> /* already setup */
> if (shared_info_page != 0 && HYPERVISOR_shared_info == shared_info_page)
> return;
> 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__ */
> --
> 1.7.2.5
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
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