event_channel.h

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/******************************************************************************
 * event_channel.h
 *
 * Event channels between domains.
 *
 * Copyright (c) 2003-2004, K A Fraser.
 */

#ifndef __XEN_PUBLIC_EVENT_CHANNEL_H__
#define __XEN_PUBLIC_EVENT_CHANNEL_H__

#include <xen/interface/xen.h>

typedef uint32_t evtchn_port_t;
DEFINE_GUEST_HANDLE(evtchn_port_t);

/*
 * EVTCHNOP_alloc_unbound: Allocate a port in domain <dom> and mark as
 * accepting interdomain bindings from domain <remote_dom>. A fresh port
 * is allocated in <dom> and returned as <port>.
 * NOTES:
 *  1. If the caller is unprivileged then <dom> must be DOMID_SELF.
 *  2. <rdom> may be DOMID_SELF, allowing loopback connections.
 */
#define EVTCHNOP_alloc_unbound    6
struct evtchn_alloc_unbound {
    /* IN parameters */
    domid_t dom, remote_dom;
    /* OUT parameters */
    evtchn_port_t port;
};

/*
 * EVTCHNOP_bind_interdomain: Construct an interdomain event channel between
 * the calling domain and <remote_dom>. <remote_dom,remote_port> must identify
 * a port that is unbound and marked as accepting bindings from the calling
 * domain. A fresh port is allocated in the calling domain and returned as
 * <local_port>.
 * NOTES:
 *  2. <remote_dom> may be DOMID_SELF, allowing loopback connections.
 */
#define EVTCHNOP_bind_interdomain 0
struct evtchn_bind_interdomain {
    /* IN parameters. */
    domid_t remote_dom;
    evtchn_port_t remote_port;
    /* OUT parameters. */
    evtchn_port_t local_port;
};

/*
 * EVTCHNOP_bind_virq: Bind a local event channel to VIRQ <irq> on specified
 * vcpu.
 * NOTES:
 *  1. A virtual IRQ may be bound to at most one event channel per vcpu.
 *  2. The allocated event channel is bound to the specified vcpu. The binding
 *     may not be changed.
 */
#define EVTCHNOP_bind_virq    1
struct evtchn_bind_virq {
    /* IN parameters. */
    uint32_t virq;
    uint32_t vcpu;
    /* OUT parameters. */
    evtchn_port_t port;
};

/*
 * EVTCHNOP_bind_pirq: Bind a local event channel to PIRQ <irq>.
 * NOTES:
 *  1. A physical IRQ may be bound to at most one event channel per domain.
 *  2. Only a sufficiently-privileged domain may bind to a physical IRQ.
 */
#define EVTCHNOP_bind_pirq    2
struct evtchn_bind_pirq {
    /* IN parameters. */
    uint32_t pirq;
#define BIND_PIRQ__WILL_SHARE 1
    uint32_t flags; /* BIND_PIRQ__* */
    /* OUT parameters. */
    evtchn_port_t port;
};

/*
 * EVTCHNOP_bind_ipi: Bind a local event channel to receive events.
 * NOTES:
 *  1. The allocated event channel is bound to the specified vcpu. The binding
 *     may not be changed.
 */
#define EVTCHNOP_bind_ipi     7
struct evtchn_bind_ipi {
    uint32_t vcpu;
    /* OUT parameters. */
    evtchn_port_t port;
};

/*
 * EVTCHNOP_close: Close a local event channel <port>. If the channel is
 * interdomain then the remote end is placed in the unbound state
 * (EVTCHNSTAT_unbound), awaiting a new connection.
 */
#define EVTCHNOP_close        3
struct evtchn_close {
    /* IN parameters. */
    evtchn_port_t port;
};

/*
 * EVTCHNOP_send: Send an event to the remote end of the channel whose local
 * endpoint is <port>.
 */
#define EVTCHNOP_send         4
struct evtchn_send {
    /* IN parameters. */
    evtchn_port_t port;
};

/*
 * EVTCHNOP_status: Get the current status of the communication channel which
 * has an endpoint at <dom, port>.
 * NOTES:
 *  1. <dom> may be specified as DOMID_SELF.
 *  2. Only a sufficiently-privileged domain may obtain the status of an event
 *     channel for which <dom> is not DOMID_SELF.
 */
#define EVTCHNOP_status       5
struct evtchn_status {
    /* IN parameters */
    domid_t  dom;
    evtchn_port_t port;
    /* OUT parameters */
#define EVTCHNSTAT_closed   0  /* Channel is not in use.             */
#define EVTCHNSTAT_unbound  1  /* Channel is waiting interdom connection.*/
#define EVTCHNSTAT_interdomain  2  /* Channel is connected to remote domain. */
#define EVTCHNSTAT_pirq     3  /* Channel is bound to a phys IRQ line.   */
#define EVTCHNSTAT_virq     4  /* Channel is bound to a virtual IRQ line */
#define EVTCHNSTAT_ipi      5  /* Channel is bound to a virtual IPI line */
    uint32_t status;
    uint32_t vcpu;         /* VCPU to which this channel is bound.   */
    union {
        struct {
            domid_t dom;
        } unbound; /* EVTCHNSTAT_unbound */
        struct {
            domid_t dom;
            evtchn_port_t port;
        } interdomain; /* EVTCHNSTAT_interdomain */
        uint32_t pirq;      /* EVTCHNSTAT_pirq        */
        uint32_t virq;      /* EVTCHNSTAT_virq        */
    } u;
};

/*
 * EVTCHNOP_bind_vcpu: Specify which vcpu a channel should notify when an
 * event is pending.
 * NOTES:
 *  1. IPI- and VIRQ-bound channels always notify the vcpu that initialised
 *     the binding. This binding cannot be changed.
 *  2. All other channels notify vcpu0 by default. This default is set when
 *     the channel is allocated (a port that is freed and subsequently reused
 *     has its binding reset to vcpu0).
 */
#define EVTCHNOP_bind_vcpu    8
struct evtchn_bind_vcpu {
    /* IN parameters. */
    evtchn_port_t port;
    uint32_t vcpu;
};

/*
 * EVTCHNOP_unmask: Unmask the specified local event-channel port and deliver
 * a notification to the appropriate VCPU if an event is pending.
 */
#define EVTCHNOP_unmask       9
struct evtchn_unmask {
    /* IN parameters. */
    evtchn_port_t port;
};

struct evtchn_op {
    uint32_t cmd; /* EVTCHNOP_* */
    union {
        struct evtchn_alloc_unbound    alloc_unbound;
        struct evtchn_bind_interdomain bind_interdomain;
        struct evtchn_bind_virq        bind_virq;
        struct evtchn_bind_pirq        bind_pirq;
        struct evtchn_bind_ipi         bind_ipi;
        struct evtchn_close        close;
        struct evtchn_send         send;
        struct evtchn_status           status;
        struct evtchn_bind_vcpu        bind_vcpu;
        struct evtchn_unmask           unmask;
    } u;
};
DEFINE_GUEST_HANDLE_STRUCT(evtchn_op);

#endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */