linux/include/xen/xen.h

#ifndef _XEN_XEN_H
#define _XEN_XEN_H

enum xen_domain_type {
	XEN_NATIVE,		/* running on bare hardware    */
	XEN_PV_DOMAIN,		/* running in a PV domain      */
	XEN_HVM_DOMAIN,		/* running in a Xen hvm domain */
};

#ifdef CONFIG_XEN
extern enum xen_domain_type xen_domain_type;
#else
#define xen_domain_type		XEN_NATIVE
#endif

#define xen_domain()		(xen_domain_type != XEN_NATIVE)
#define xen_pv_domain()		(xen_domain() &&			\
				 xen_domain_type == XEN_PV_DOMAIN)
#define xen_hvm_domain()	(xen_domain() &&			\
				 xen_domain_type == XEN_HVM_DOMAIN)

#ifdef CONFIG_XEN_DOM0
#include <xen/interface/xen.h>
#include <asm/xen/hypervisor.h>

#define xen_initial_domain()	(xen_domain() && \
				 xen_start_info && xen_start_info->flags & SIF_INITDOMAIN)
#else  /* !CONFIG_XEN_DOM0 */
#define xen_initial_domain()	(0)
#endif	/* CONFIG_XEN_DOM0 */

#ifdef CONFIG_XEN_PVH
/* This functionality exists only for x86. The XEN_PVHVM support exists
 * only in x86 world - hence on ARM it will be always disabled.
 * N.B. ARM guests are neither PV nor HVM nor PVHVM.
 * It's a bit like PVH but is different also (it's further towards the H
 * end of the spectrum than even PVH).
 */
#include <xen/features.h>
#define xen_pvh_domain() (xen_pv_domain() && \
			  xen_feature(XENFEAT_auto_translated_physmap))
#else
#define xen_pvh_domain()	(0)
#endif
#endif	/* _XEN_XEN_H */