53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/******************************************************************************
|
|
* features.c
|
|
*
|
|
* Xen feature flags.
|
|
*
|
|
* Copyright (c) 2006, Ian Campbell, XenSource Inc.
|
|
*/
|
|
#include <linux/types.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/export.h>
|
|
#include <linux/printk.h>
|
|
|
|
#include <asm/xen/hypercall.h>
|
|
|
|
#include <xen/xen.h>
|
|
#include <xen/interface/xen.h>
|
|
#include <xen/interface/version.h>
|
|
#include <xen/features.h>
|
|
|
|
/*
|
|
* Linux kernel expects at least Xen 4.0.
|
|
*
|
|
* Assume some features to be available for that reason (depending on guest
|
|
* mode, of course).
|
|
*/
|
|
#define chk_required_feature(f) { \
|
|
if (!xen_feature(f)) \
|
|
panic("Xen: feature %s not available!\n", #f); \
|
|
}
|
|
|
|
u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
|
|
EXPORT_SYMBOL_GPL(xen_features);
|
|
|
|
void xen_setup_features(void)
|
|
{
|
|
struct xen_feature_info fi;
|
|
int i, j;
|
|
|
|
for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
|
|
fi.submap_idx = i;
|
|
if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
|
|
break;
|
|
for (j = 0; j < 32; j++)
|
|
xen_features[i * 32 + j] = !!(fi.submap & 1U << j);
|
|
}
|
|
|
|
if (xen_pv_domain()) {
|
|
chk_required_feature(XENFEAT_mmu_pt_update_preserve_ad);
|
|
chk_required_feature(XENFEAT_gnttab_map_avail_bits);
|
|
}
|
|
}
|