xref: /linux/drivers/xen/features.c (revision 7ff836f064e2c814a7504c91a4464eea45d475bd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /******************************************************************************
3  * features.c
4  *
5  * Xen feature flags.
6  *
7  * Copyright (c) 2006, Ian Campbell, XenSource Inc.
8  */
9 #include <linux/types.h>
10 #include <linux/cache.h>
11 #include <linux/export.h>
12 
13 #include <asm/xen/hypercall.h>
14 
15 #include <xen/interface/xen.h>
16 #include <xen/interface/version.h>
17 #include <xen/features.h>
18 
19 u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
20 EXPORT_SYMBOL_GPL(xen_features);
21 
22 void xen_setup_features(void)
23 {
24 	struct xen_feature_info fi;
25 	int i, j;
26 
27 	for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
28 		fi.submap_idx = i;
29 		if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
30 			break;
31 		for (j = 0; j < 32; j++)
32 			xen_features[i * 32 + j] = !!(fi.submap & 1<<j);
33 	}
34 }
35