    /* SPDX-License-Identifier: MIT */
    /******************************************************************************
     * features.h
     *
     * Feature flags, reported by XENVER_get_features.
     *
     * Copyright (c) 2006, Keir Fraser <keir@xensource.com>
     */

    #ifndef __XEN_PUBLIC_FEATURES_H__
    #define __XEN_PUBLIC_FEATURES_H__

    /*
     * `incontents 200 elfnotes_features XEN_ELFNOTE_FEATURES
     *
     * The list of all the features the guest supports. They are set by
     * parsing the XEN_ELFNOTE_FEATURES and XEN_ELFNOTE_SUPPORTED_FEATURES
     * string. The format is the  feature names (as given here without the
     * "XENFEAT_" prefix) separated by '|' characters.
     * If a feature is required for the kernel to function then the feature name
     * must be preceded by a '!' character.
     *
     * Note that if XEN_ELFNOTE_SUPPORTED_FEATURES is used, then in the
     * XENFEAT_dom0 MUST be set if the guest is to be booted as dom0,
     */

    /*
     * If set, the guest does not need to write-protect its pagetables, and can
     * update them via direct writes.
     */
    #define XENFEAT_writable_page_tables       0

    /*
     * If set, the guest does not need to write-protect its segment descriptor
     * tables, and can update them via direct writes.
     */
    #define XENFEAT_writable_descriptor_tables 1

    /*
     * If set, translation between the guest's 'pseudo-physical' address space
     * and the host's machine address space are handled by the hypervisor. In this
     * mode the guest does not need to perform phys-to/from-machine translations
     * when performing page table operations.
     */
    #define XENFEAT_auto_translated_physmap    2

    /* If set, the guest is running in supervisor mode (e.g., x86 ring 0). */
    #define XENFEAT_supervisor_mode_kernel     3

    /*
     * If set, the guest does not need to allocate x86 PAE page directories
     * below 4GB. This flag is usually implied by auto_translated_physmap.
     */
    #define XENFEAT_pae_pgdir_above_4gb        4

    /* x86: Does this Xen host support the MMU_PT_UPDATE_PRESERVE_AD hypercall? */
    #define XENFEAT_mmu_pt_update_preserve_ad  5

    /* x86: Does this Xen host support the MMU_{CLEAR,COPY}_PAGE hypercall? */
    #define XENFEAT_highmem_assist             6

    /*
     * If set, GNTTABOP_map_grant_ref honors flags to be placed into guest kernel
     * available pte bits.
     */
    #define XENFEAT_gnttab_map_avail_bits      7

    /* x86: Does this Xen host support the HVM callback vector type? */
    #define XENFEAT_hvm_callback_vector        8

    /* x86: pvclock algorithm is safe to use on HVM */
    #define XENFEAT_hvm_safe_pvclock           9

    /* x86: pirq can be used by HVM guests */
    #define XENFEAT_hvm_pirqs                 10

    /* operation as Dom0 is supported */
    #define XENFEAT_dom0                      11

    /* Xen also maps grant references at pfn = mfn.
     * This feature flag is deprecated and should not be used.
    #define XENFEAT_grant_map_identity        12
     */

    /* Guest can use XENMEMF_vnode to specify virtual node for memory op. */
    #define XENFEAT_memory_op_vnode_supported 13

    /* arm: Hypervisor supports ARM SMC calling convention. */
    #define XENFEAT_ARM_SMCCC_supported       14

    /*
     * x86/PVH: If set, ACPI RSDP can be placed at any address. Otherwise RSDP
     * must be located in lower 1MB, as required by ACPI Specification for IA-PC
     * systems.
     * This feature flag is only consulted if XEN_ELFNOTE_GUEST_OS contains
     * the "linux" string.
     */
    #define XENFEAT_linux_rsdp_unrestricted   15

    /*
     * A direct-mapped (or 1:1 mapped) domain is a domain for which its
     * local pages have gfn == mfn. If a domain is direct-mapped,
     * XENFEAT_direct_mapped is set; otherwise XENFEAT_not_direct_mapped
     * is set.
     *
     * If neither flag is set (e.g. older Xen releases) the assumptions are:
     * - not auto_translated domains (x86 only) are always direct-mapped
     * - on x86, auto_translated domains are not direct-mapped
     * - on ARM, Dom0 is direct-mapped, DomUs are not
     */
    #define XENFEAT_not_direct_mapped         16
    #define XENFEAT_direct_mapped             17

    /*
     * Signal whether the domain is able to use the following hypercalls:
     *
     * VCPUOP_register_runstate_phys_area
     * VCPUOP_register_vcpu_time_phys_area
     */
    #define XENFEAT_runstate_phys_area        18
    #define XENFEAT_vcpu_time_phys_area       19

    /*
     * If set, Xen will passthrough all MSI-X vector ctrl writes to device model,
     * not only those unmasking an entry. This allows device model to properly keep
     * track of the MSI-X table without having to read it from the device behind
     * Xen's backs. This information is relevant only for device models.
     */
    #define XENFEAT_dm_msix_all_writes        20

    #define XENFEAT_NR_SUBMAPS 1

    #endif /* __XEN_PUBLIC_FEATURES_H__ */

    /*
     * Local variables:
     * mode: C
     * c-file-style: "BSD"
     * c-basic-offset: 4
     * tab-width: 4
     * indent-tabs-mode: nil
     * End:
     */