ref: b07a6e33bd1d0653709e4789ee7463a6ff102f67
dir: /sys/src/9/xen/xen-public/event_channel.h/
/******************************************************************************
* event_channel.h
*
* Event channels between domains.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Copyright (c) 2003-2004, K A Fraser.
*/
#ifndef __XEN_PUBLIC_EVENT_CHANNEL_H__
#define __XEN_PUBLIC_EVENT_CHANNEL_H__
#include "xen.h"
/*
* `incontents 150 evtchn Event Channels
*
* Event channels are the basic primitive provided by Xen for event
* notifications. An event is the Xen equivalent of a hardware
* interrupt. They essentially store one bit of information, the event
* of interest is signalled by transitioning this bit from 0 to 1.
*
* Notifications are received by a guest via an upcall from Xen,
* indicating when an event arrives (setting the bit). Further
* notifications are masked until the bit is cleared again (therefore,
* guests must check the value of the bit after re-enabling event
* delivery to ensure no missed notifications).
*
* Event notifications can be masked by setting a flag; this is
* equivalent to disabling interrupts and can be used to ensure
* atomicity of certain operations in the guest kernel.
*
* Event channels are represented by the evtchn_* fields in
* struct shared_info and struct vcpu_info.
*/
/*
* ` enum neg_errnoval
* ` HYPERVISOR_event_channel_op(enum event_channel_op cmd, void *args)
* `
* @cmd == EVTCHNOP_* (event-channel operation).
* @args == struct evtchn_* Operation-specific extra arguments (NULL if none).
*/
/* ` enum event_channel_op { // EVTCHNOP_* => struct evtchn_* */
#define EVTCHNOP_bind_interdomain 0
#define EVTCHNOP_bind_virq 1
#define EVTCHNOP_bind_pirq 2
#define EVTCHNOP_close 3
#define EVTCHNOP_send 4
#define EVTCHNOP_status 5
#define EVTCHNOP_alloc_unbound 6
#define EVTCHNOP_bind_ipi 7
#define EVTCHNOP_bind_vcpu 8
#define EVTCHNOP_unmask 9
#define EVTCHNOP_reset 10
/* ` } */
typedef uint32_t evtchn_port_t;
DEFINE_XEN_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.
*/
struct evtchn_alloc_unbound {
/* IN parameters */
domid_t dom, remote_dom;
/* OUT parameters */
evtchn_port_t port;
};
typedef struct evtchn_alloc_unbound evtchn_alloc_unbound_t;
/*
* 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:
* 1. <remote_dom> may be DOMID_SELF, allowing loopback connections.
*/
struct evtchn_bind_interdomain {
/* IN parameters. */
domid_t remote_dom;
evtchn_port_t remote_port;
/* OUT parameters. */
evtchn_port_t local_port;
};
typedef struct evtchn_bind_interdomain evtchn_bind_interdomain_t;
/*
* EVTCHNOP_bind_virq: Bind a local event channel to VIRQ <irq> on specified
* vcpu.
* NOTES:
* 1. Virtual IRQs are classified as per-vcpu or global. See the VIRQ list
* in xen.h for the classification of each VIRQ.
* 2. Global VIRQs must be allocated on VCPU0 but can subsequently be
* re-bound via EVTCHNOP_bind_vcpu.
* 3. Per-vcpu VIRQs may be bound to at most one event channel per vcpu.
* The allocated event channel is bound to the specified vcpu and the
* binding cannot be changed.
*/
struct evtchn_bind_virq {
/* IN parameters. */
uint32_t virq; /* enum virq */
uint32_t vcpu;
/* OUT parameters. */
evtchn_port_t port;
};
typedef struct evtchn_bind_virq evtchn_bind_virq_t;
/*
* EVTCHNOP_bind_pirq: Bind a local event channel to a real IRQ (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.
*/
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;
};
typedef struct evtchn_bind_pirq evtchn_bind_pirq_t;
/*
* 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.
*/
struct evtchn_bind_ipi {
uint32_t vcpu;
/* OUT parameters. */
evtchn_port_t port;
};
typedef struct evtchn_bind_ipi evtchn_bind_ipi_t;
/*
* 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.
*/
struct evtchn_close {
/* IN parameters. */
evtchn_port_t port;
};
typedef struct evtchn_close evtchn_close_t;
/*
* EVTCHNOP_send: Send an event to the remote end of the channel whose local
* endpoint is <port>.
*/
struct evtchn_send {
/* IN parameters. */
evtchn_port_t port;
};
typedef struct evtchn_send evtchn_send_t;
/*
* 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.
*/
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;
};
typedef struct evtchn_status evtchn_status_t;
/*
* EVTCHNOP_bind_vcpu: Specify which vcpu a channel should notify when an
* event is pending.
* NOTES:
* 1. IPI-bound channels always notify the vcpu specified at bind time.
* This binding cannot be changed.
* 2. Per-VCPU VIRQ channels always notify the vcpu specified at bind time.
* This binding cannot be changed.
* 3. 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).
*/
struct evtchn_bind_vcpu {
/* IN parameters. */
evtchn_port_t port;
uint32_t vcpu;
};
typedef struct evtchn_bind_vcpu evtchn_bind_vcpu_t;
/*
* EVTCHNOP_unmask: Unmask the specified local event-channel port and deliver
* a notification to the appropriate VCPU if an event is pending.
*/
struct evtchn_unmask {
/* IN parameters. */
evtchn_port_t port;
};
typedef struct evtchn_unmask evtchn_unmask_t;
/*
* EVTCHNOP_reset: Close all event channels associated with specified domain.
* NOTES:
* 1. <dom> may be specified as DOMID_SELF.
* 2. Only a sufficiently-privileged domain may specify other than DOMID_SELF.
*/
struct evtchn_reset {
/* IN parameters. */
domid_t dom;
};
typedef struct evtchn_reset evtchn_reset_t;
/*
* ` enum neg_errnoval
* ` HYPERVISOR_event_channel_op_compat(struct evtchn_op *op)
* `
* Superceded by new event_channel_op() hypercall since 0x00030202.
*/
struct evtchn_op {
uint32_t cmd; /* enum event_channel_op */
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;
};
typedef struct evtchn_op evtchn_op_t;
DEFINE_XEN_GUEST_HANDLE(evtchn_op_t);
#endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/