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