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 <redacted>
---
 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);

+
 	/* 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__ */