1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2af711cdaSIsaku Yamahata /****************************************************************************** 3af711cdaSIsaku Yamahata * features.c 4af711cdaSIsaku Yamahata * 5af711cdaSIsaku Yamahata * Xen feature flags. 6af711cdaSIsaku Yamahata * 7af711cdaSIsaku Yamahata * Copyright (c) 2006, Ian Campbell, XenSource Inc. 8af711cdaSIsaku Yamahata */ 9af711cdaSIsaku Yamahata #include <linux/types.h> 10af711cdaSIsaku Yamahata #include <linux/cache.h> 1159aa56bfSPaul Gortmaker #include <linux/export.h> 12ac4c403cSJuergen Gross #include <linux/printk.h> 13ecbf29cdSJeremy Fitzhardinge 14ecbf29cdSJeremy Fitzhardinge #include <asm/xen/hypercall.h> 15ecbf29cdSJeremy Fitzhardinge 16ac4c403cSJuergen Gross #include <xen/xen.h> 17ecbf29cdSJeremy Fitzhardinge #include <xen/interface/xen.h> 18ecbf29cdSJeremy Fitzhardinge #include <xen/interface/version.h> 19af711cdaSIsaku Yamahata #include <xen/features.h> 20af711cdaSIsaku Yamahata 21ac4c403cSJuergen Gross /* 22ac4c403cSJuergen Gross * Linux kernel expects at least Xen 4.0. 23ac4c403cSJuergen Gross * 24ac4c403cSJuergen Gross * Assume some features to be available for that reason (depending on guest 25ac4c403cSJuergen Gross * mode, of course). 26ac4c403cSJuergen Gross */ 27ac4c403cSJuergen Gross #define chk_required_feature(f) { \ 28ac4c403cSJuergen Gross if (!xen_feature(f)) \ 29ac4c403cSJuergen Gross panic("Xen: feature %s not available!\n", #f); \ 30ac4c403cSJuergen Gross } 31ac4c403cSJuergen Gross 32af711cdaSIsaku Yamahata u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly; 33af711cdaSIsaku Yamahata EXPORT_SYMBOL_GPL(xen_features); 34af711cdaSIsaku Yamahata xen_setup_features(void)35af711cdaSIsaku Yamahatavoid xen_setup_features(void) 36af711cdaSIsaku Yamahata { 37af711cdaSIsaku Yamahata struct xen_feature_info fi; 38af711cdaSIsaku Yamahata int i, j; 39af711cdaSIsaku Yamahata 40af711cdaSIsaku Yamahata for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) { 41af711cdaSIsaku Yamahata fi.submap_idx = i; 42af711cdaSIsaku Yamahata if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0) 43af711cdaSIsaku Yamahata break; 44af711cdaSIsaku Yamahata for (j = 0; j < 32; j++) 45*ecb6237fSJulien Grall xen_features[i * 32 + j] = !!(fi.submap & 1U << j); 46af711cdaSIsaku Yamahata } 47ac4c403cSJuergen Gross 48ac4c403cSJuergen Gross if (xen_pv_domain()) { 49ac4c403cSJuergen Gross chk_required_feature(XENFEAT_mmu_pt_update_preserve_ad); 50ac4c403cSJuergen Gross chk_required_feature(XENFEAT_gnttab_map_avail_bits); 51ac4c403cSJuergen Gross } 52af711cdaSIsaku Yamahata } 53