features.c 803 B

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  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. #include <asm/xen/hypercall.h>
  13. #include <xen/interface/xen.h>
  14. #include <xen/interface/version.h>
  15. #include <xen/features.h>
  16. u8 xen_features[XENFEAT_NR_SUBMAPS * 32] __read_mostly;
  17. EXPORT_SYMBOL_GPL(xen_features);
  18. void xen_setup_features(void)
  19. {
  20. struct xen_feature_info fi;
  21. int i, j;
  22. for (i = 0; i < XENFEAT_NR_SUBMAPS; i++) {
  23. fi.submap_idx = i;
  24. if (HYPERVISOR_xen_version(XENVER_get_features, &fi) < 0)
  25. break;
  26. for (j = 0; j < 32; j++)
  27. xen_features[i * 32 + j] = !!(fi.submap & 1<<j);
  28. }
  29. }