1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* IRQ offload/bypass manager
*
* Copyright (C) 2015 Red Hat, Inc.
* Copyright (c) 2015 Linaro Ltd.
*/
#ifndef IRQBYPASS_H
#define IRQBYPASS_H
#include <linux/list.h>
struct eventfd_ctx;
struct irq_bypass_consumer;
/*
* Theory of operation
*
* The IRQ bypass manager is a simple set of lists and callbacks that allows
* IRQ producers (ex. physical interrupt sources) to be matched to IRQ
* consumers (ex. virtualization hardware that allows IRQ bypass or offload)
* via a shared eventfd_ctx. Producers and consumers register independently.
* When a producer and consumer are paired, i.e. an eventfd match is found, the
* optional @stop callback will be called for each participant. The pair will
* then be connected via the @add_* callbacks, and finally the optional @start
* callback will allow any final coordination. When either participant is
* unregistered, the process is repeated using the @del_* callbacks in place of
* the @add_* callbacks. eventfds must be unique per producer/consumer, 1:N
* pairings are not supported.
*/
struct irq_bypass_consumer;
/**
* struct irq_bypass_producer - IRQ bypass producer definition
* @eventfd: eventfd context used to match producers and consumers
* @consumer: The connected consumer (NULL if no connection)
* @irq: Linux IRQ number for the producer device
* @add_consumer: Connect the IRQ producer to an IRQ consumer (optional)
* @del_consumer: Disconnect the IRQ producer from an IRQ consumer (optional)
* @stop: Perform any quiesce operations necessary prior to add/del (optional)
* @start: Perform any startup operations necessary after add/del (optional)
*
* The IRQ bypass producer structure represents an interrupt source for
* participation in possible host bypass, for instance an interrupt vector
* for a physical device assigned to a VM.
*/
struct irq_bypass_producer {
struct eventfd_ctx *eventfd;
struct irq_bypass_consumer *consumer;
int irq;
int (*add_consumer)(struct irq_bypass_producer *,
struct irq_bypass_consumer *);
void (*del_consumer)(struct irq_bypass_producer *,
struct irq_bypass_consumer *);
void (*stop)(struct irq_bypass_producer *);
void (*start)(struct irq_bypass_producer *);
};
/**
* struct irq_bypass_consumer - IRQ bypass consumer definition
* @eventfd: eventfd context used to match producers and consumers
* @producer: The connected producer (NULL if no connection)
* @add_producer: Connect the IRQ consumer to an IRQ producer
* @del_producer: Disconnect the IRQ consumer from an IRQ producer
* @stop: Perform any quiesce operations necessary prior to add/del (optional)
* @start: Perform any startup operations necessary after add/del (optional)
*
* The IRQ bypass consumer structure represents an interrupt sink for
* participation in possible host bypass, for instance a hypervisor may
* support offloads to allow bypassing the host entirely or offload
* portions of the interrupt handling to the VM.
*/
struct irq_bypass_consumer {
struct eventfd_ctx *eventfd;
struct irq_bypass_producer *producer;
int (*add_producer)(struct irq_bypass_consumer *,
struct irq_bypass_producer *);
void (*del_producer)(struct irq_bypass_consumer *,
struct irq_bypass_producer *);
void (*stop)(struct irq_bypass_consumer *);
void (*start)(struct irq_bypass_consumer *);
};
int irq_bypass_register_producer(struct irq_bypass_producer *producer,
struct eventfd_ctx *eventfd, int irq);
void irq_bypass_unregister_producer(struct irq_bypass_producer *producer);
int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer,
struct eventfd_ctx *eventfd);
void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer);
#endif /* IRQBYPASS_H */
|
