freebsd-dev/sys/contrib/xen/event_channel.h
Roger Pau Monné 3a9fd8242b xen: import Xen 4.16 public headers in sys/contrib/
The current path of the Xen headers at /sys/xen/interface/ is not
correct, as those headers are imported verbatim from the Xen sources
and shouldn't be modified, as any modifications would be lost when a
new version is imported.

Changes to the public headers must be first done in Xen upstream so
that they can be backported and new imports will already carry them.

Import Xen 4.16 headers in sys/contrib/xen/. It's unlikely that we
will import different Xen code, so don't place them inside of any
subdirectory. If in the future other pieces of Xen code need to be
imported the headers will need to move into an include/ subdirectory.

Note that this commit does not yet modify the include path to use the
newly imported headers.

Sponsored by: Citrix Systems R&D
2022-02-07 10:11:56 +01:00

389 lines
12 KiB
C

/******************************************************************************
* 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
#define EVTCHNOP_init_control 11
#define EVTCHNOP_expand_array 12
#define EVTCHNOP_set_priority 13
#ifdef __XEN__
#define EVTCHNOP_reset_cont 14
#endif
/* ` } */
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. <remote_dom> 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>.
*
* In case the peer domain has already tried to set our event channel
* pending, before it was bound, EVTCHNOP_bind_interdomain always sets
* the local event channel pending.
*
* The usual pattern of use, in the guest's upcall (or subsequent
* handler) is as follows: (Re-enable the event channel for subsequent
* signalling and then) check for the existence of whatever condition
* is being waited for by other means, and take whatever action is
* needed (if any).
*
* 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.
* 3. Destroys all control blocks and event array, resets event channel
* operations to 2-level ABI if called with <dom> == DOMID_SELF and FIFO
* ABI was used. Guests should not bind events during EVTCHNOP_reset call
* as these events are likely to be lost.
*/
struct evtchn_reset {
/* IN parameters. */
domid_t dom;
};
typedef struct evtchn_reset evtchn_reset_t;
/*
* EVTCHNOP_init_control: initialize the control block for the FIFO ABI.
*
* Note: any events that are currently pending will not be resent and
* will be lost. Guests should call this before binding any event to
* avoid losing any events.
*/
struct evtchn_init_control {
/* IN parameters. */
uint64_t control_gfn;
uint32_t offset;
uint32_t vcpu;
/* OUT parameters. */
uint8_t link_bits;
uint8_t _pad[7];
};
typedef struct evtchn_init_control evtchn_init_control_t;
/*
* EVTCHNOP_expand_array: add an additional page to the event array.
*/
struct evtchn_expand_array {
/* IN parameters. */
uint64_t array_gfn;
};
typedef struct evtchn_expand_array evtchn_expand_array_t;
/*
* EVTCHNOP_set_priority: set the priority for an event channel.
*/
struct evtchn_set_priority {
/* IN parameters. */
evtchn_port_t port;
uint32_t priority;
};
typedef struct evtchn_set_priority evtchn_set_priority_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 {
evtchn_alloc_unbound_t alloc_unbound;
evtchn_bind_interdomain_t bind_interdomain;
evtchn_bind_virq_t bind_virq;
evtchn_bind_pirq_t bind_pirq;
evtchn_bind_ipi_t bind_ipi;
evtchn_close_t close;
evtchn_send_t send;
evtchn_status_t status;
evtchn_bind_vcpu_t bind_vcpu;
evtchn_unmask_t unmask;
} u;
};
typedef struct evtchn_op evtchn_op_t;
DEFINE_XEN_GUEST_HANDLE(evtchn_op_t);
/*
* 2-level ABI
*/
#define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
/*
* FIFO ABI
*/
/* Events may have priorities from 0 (highest) to 15 (lowest). */
#define EVTCHN_FIFO_PRIORITY_MAX 0
#define EVTCHN_FIFO_PRIORITY_DEFAULT 7
#define EVTCHN_FIFO_PRIORITY_MIN 15
#define EVTCHN_FIFO_MAX_QUEUES (EVTCHN_FIFO_PRIORITY_MIN + 1)
typedef uint32_t event_word_t;
#define EVTCHN_FIFO_PENDING 31
#define EVTCHN_FIFO_MASKED 30
#define EVTCHN_FIFO_LINKED 29
#define EVTCHN_FIFO_BUSY 28
#define EVTCHN_FIFO_LINK_BITS 17
#define EVTCHN_FIFO_LINK_MASK ((1 << EVTCHN_FIFO_LINK_BITS) - 1)
#define EVTCHN_FIFO_NR_CHANNELS (1 << EVTCHN_FIFO_LINK_BITS)
struct evtchn_fifo_control_block {
uint32_t ready;
uint32_t _rsvd;
uint32_t head[EVTCHN_FIFO_MAX_QUEUES];
};
typedef struct evtchn_fifo_control_block evtchn_fifo_control_block_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:
*/