    /* SPDX-License-Identifier: MIT */
    /******************************************************************************
     * vcpu.h
     *
     * VCPU initialisation, query, and hotplug.
     *
     * Copyright (c) 2005, Keir Fraser <keir@xensource.com>
     */

    #ifndef __XEN_PUBLIC_VCPU_H__
    #define __XEN_PUBLIC_VCPU_H__

    #include "xen.h"

    /*
     * Prototype for this hypercall is:
     *  long vcpu_op(int cmd, unsigned int vcpuid, void *extra_args)
     * @cmd        == VCPUOP_??? (VCPU operation).
     * @vcpuid     == VCPU to operate on.
     * @extra_args == Operation-specific extra arguments (NULL if none).
     */

    /*
     * Initialise a VCPU. Each VCPU can be initialised only once. A
     * newly-initialised VCPU will not run until it is brought up by VCPUOP_up.
     *
     * @extra_arg == For PV or ARM guests this is a pointer to a vcpu_guest_context
     *               structure containing the initial state for the VCPU. For x86
     *               HVM based guests this is a pointer to a vcpu_hvm_context
     *               structure.
     */
    #define VCPUOP_initialise            0

    /*
     * Bring up a VCPU. This makes the VCPU runnable. This operation will fail
     * if the VCPU has not been initialised (VCPUOP_initialise).
     */
    #define VCPUOP_up                    1

    /*
     * Bring down a VCPU (i.e., make it non-runnable).
     * There are a few caveats that callers should observe:
     *  1. This operation may return, and VCPU_is_up may return false, before the
     *     VCPU stops running (i.e., the command is asynchronous). It is a good
     *     idea to ensure that the VCPU has entered a non-critical loop before
     *     bringing it down. Alternatively, this operation is guaranteed
     *     synchronous if invoked by the VCPU itself.
     *  2. After a VCPU is initialised, there is currently no way to drop all its
     *     references to domain memory. Even a VCPU that is down still holds
     *     memory references via its pagetable base pointer and GDT. It is good
     *     practise to move a VCPU onto an 'idle' or default page table, LDT and
     *     GDT before bringing it down.
     */
    #define VCPUOP_down                  2

    /* Returns 1 if the given VCPU is up. */
    #define VCPUOP_is_up                 3

    /*
     * Return information about the state and running time of a VCPU.
     * @extra_arg == pointer to vcpu_runstate_info structure.
     */
    #define VCPUOP_get_runstate_info     4
    struct vcpu_runstate_info {
        /* VCPU's current state (RUNSTATE_*). */
        int      state;
        /* When was current state entered (system time, ns)? */
        uint64_t state_entry_time;
        /*
         * Update indicator set in state_entry_time:
         * When activated via VMASST_TYPE_runstate_update_flag, set during
         * updates in guest memory mapped copy of vcpu_runstate_info.
         */
    #define XEN_RUNSTATE_UPDATE          (xen_mk_ullong(1) << 63)
        /*
         * Time spent in each RUNSTATE_* (ns). The sum of these times is
         * guaranteed not to drift from system time.
         */
        uint64_t time[4];
    };
    typedef struct vcpu_runstate_info vcpu_runstate_info_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_runstate_info_t);

    /* VCPU is currently running on a physical CPU. */
    #define RUNSTATE_running  0

    /* VCPU is runnable, but not currently scheduled on any physical CPU. */
    #define RUNSTATE_runnable 1

    /* VCPU is blocked (a.k.a. idle). It is therefore not runnable. */
    #define RUNSTATE_blocked  2

    /*
     * VCPU is not runnable, but it is not blocked.
     * This is a 'catch all' state for things like hotplug and pauses by the
     * system administrator (or for critical sections in the hypervisor).
     * RUNSTATE_blocked dominates this state (it is the preferred state).
     */
    #define RUNSTATE_offline  3

    /*
     * Register a shared memory area from which the guest may obtain its own
     * runstate information without needing to execute a hypercall.
     * Notes:
     *  1. The registered address may be virtual or physical or guest handle,
     *     depending on the platform. Virtual address or guest handle should be
     *     registered on x86 systems.
     *  2. Only one shared area may be registered per VCPU. The shared area is
     *     updated by the hypervisor each time the VCPU is scheduled. Thus
     *     runstate.state will always be RUNSTATE_running and
     *     runstate.state_entry_time will indicate the system time at which the
     *     VCPU was last scheduled to run.
     *  3. New code wants to prefer VCPUOP_register_runstate_phys_area, and only
     *     fall back to the operation here for backwards compatibility.
     * @extra_arg == pointer to vcpu_register_runstate_memory_area structure.
     */
    #define VCPUOP_register_runstate_memory_area 5
    struct vcpu_register_runstate_memory_area {
        union {
            XEN_GUEST_HANDLE(vcpu_runstate_info_t) h;
            struct vcpu_runstate_info *v;
            uint64_t p;
        } addr;
    };
    typedef struct vcpu_register_runstate_memory_area vcpu_register_runstate_memory_area_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_register_runstate_memory_area_t);

    /*
     * Set or stop a VCPU's periodic timer. Every VCPU has one periodic timer
     * which can be set via these commands. Periods smaller than one millisecond
     * may not be supported.
     */
    #define VCPUOP_set_periodic_timer    6 /* arg == vcpu_set_periodic_timer_t */
    #define VCPUOP_stop_periodic_timer   7 /* arg == NULL */
    struct vcpu_set_periodic_timer {
        uint64_t period_ns;
    };
    typedef struct vcpu_set_periodic_timer vcpu_set_periodic_timer_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_set_periodic_timer_t);

    /*
     * Set or stop a VCPU's single-shot timer. Every VCPU has one single-shot
     * timer which can be set via these commands.
     */
    #define VCPUOP_set_singleshot_timer  8 /* arg == vcpu_set_singleshot_timer_t */
    #define VCPUOP_stop_singleshot_timer 9 /* arg == NULL */
    struct vcpu_set_singleshot_timer {
        uint64_t timeout_abs_ns;   /* Absolute system time value in nanoseconds. */
        uint32_t flags;            /* VCPU_SSHOTTMR_??? */
    };
    typedef struct vcpu_set_singleshot_timer vcpu_set_singleshot_timer_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_set_singleshot_timer_t);

    /* Flags to VCPUOP_set_singleshot_timer. */
     /*
      * Request the timeout to be in the future (return -ETIME if it's passed)
      * but can be ignored by the hypervisor.
      */
    #define _VCPU_SSHOTTMR_future (0)
    #define VCPU_SSHOTTMR_future  (1U << _VCPU_SSHOTTMR_future)

    /*
     * Register a memory location in the guest address space for the
     * vcpu_info structure.  This allows the guest to place the vcpu_info
     * structure in a convenient place, such as in a per-cpu data area.
     * The pointer need not be page aligned, but the structure must not
     * cross a page boundary.
     *
     * This may be called only once per vcpu.
     */
    #define VCPUOP_register_vcpu_info   10  /* arg == vcpu_register_vcpu_info_t */
    struct vcpu_register_vcpu_info {
        uint64_t mfn;    /* mfn of page to place vcpu_info */
        uint32_t offset; /* offset within page */
        uint32_t rsvd;   /* unused */
    };
    typedef struct vcpu_register_vcpu_info vcpu_register_vcpu_info_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_register_vcpu_info_t);

    /* Send an NMI to the specified VCPU. @extra_arg == NULL. */
    #define VCPUOP_send_nmi             11

    /*
     * Get the physical ID information for a pinned vcpu's underlying physical
     * processor.  The physical ID informmation is architecture-specific.
     * On x86: id[31:0]=apic_id, id[63:32]=acpi_id.
     * This command returns -EINVAL if it is not a valid operation for this VCPU.
     */
    #define VCPUOP_get_physid           12 /* arg == vcpu_get_physid_t */
    struct vcpu_get_physid {
        uint64_t phys_id;
    };
    typedef struct vcpu_get_physid vcpu_get_physid_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_get_physid_t);
    #define xen_vcpu_physid_to_x86_apicid(physid) ((uint32_t)(physid))
    #define xen_vcpu_physid_to_x86_acpiid(physid) ((uint32_t)((physid) >> 32))

    /*
     * Register a memory location to get a secondary copy of the vcpu time
     * parameters.  The master copy still exists as part of the vcpu shared
     * memory area, and this secondary copy is updated whenever the master copy
     * is updated (and using the same versioning scheme for synchronisation).
     *
     * The intent is that this copy may be mapped (RO) into userspace so
     * that usermode can compute system time using the time info and the
     * tsc.  Usermode will see an array of vcpu_time_info structures, one
     * for each vcpu, and choose the right one by an existing mechanism
     * which allows it to get the current vcpu number (such as via a
     * segment limit).  It can then apply the normal algorithm to compute
     * system time from the tsc.
     *
     * New code wants to prefer VCPUOP_register_vcpu_time_phys_area, and only
     * fall back to the operation here for backwards compatibility.
     *
     * @extra_arg == pointer to vcpu_register_time_info_memory_area structure.
     */
    #define VCPUOP_register_vcpu_time_memory_area   13
    DEFINE_XEN_GUEST_HANDLE(vcpu_time_info_t);
    struct vcpu_register_time_memory_area {
        union {
            XEN_GUEST_HANDLE(vcpu_time_info_t) h;
            struct vcpu_time_info *v;
            uint64_t p;
        } addr;
    };
    typedef struct vcpu_register_time_memory_area vcpu_register_time_memory_area_t;
    DEFINE_XEN_GUEST_HANDLE(vcpu_register_time_memory_area_t);

    /*
     * Like the respective VCPUOP_register_*_memory_area, just using the "addr.p"
     * field of the supplied struct as a guest physical address (i.e. in GFN space).
     * The respective area may not cross a page boundary.  Pass ~0 to unregister an
     * area.  Note that as long as an area is registered by physical address, the
     * linear address based area will not be serviced (updated) by the hypervisor.
     *
     * Note that the area registered via VCPUOP_register_runstate_memory_area will
     * be updated in the same manner as the one registered via virtual address PLUS
     * VMASST_TYPE_runstate_update_flag engaged by the domain.
     *
     * XENFEAT_{runstate,vcpu_time}_phys_area feature bits signal the availability
     * of these ops.
     */
    #define VCPUOP_register_runstate_phys_area      14
    #define VCPUOP_register_vcpu_time_phys_area     15

    #endif /* __XEN_PUBLIC_VCPU_H__ */

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