qemu-e2k/include/hw/xen/xen-bus.h
Paul Durrant 345f42b4be xen-bus / xen-block: add support for event channel polling
This patch introduces a poll callback for event channel fd-s and uses
this to invoke the channel callback function.

To properly support polling, it is necessary for the event channel callback
function to return a boolean saying whether it has done any useful work or
not. Thus xen_block_dataplane_event() is modified to directly invoke
xen_block_handle_requests() and the latter only returns true if it actually
processes any requests. This also means that the call to qemu_bh_schedule()
is moved into xen_block_complete_aio(), which is more intuitive since the
only reason for doing a deferred poll of the shared ring should be because
there were previously insufficient resources to fully complete a previous
poll.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Message-Id: <20190408151617.13025-4-paul.durrant@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
2019-06-24 10:42:29 +01:00

137 lines
4.6 KiB
C

/*
* Copyright (c) 2018 Citrix Systems Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef HW_XEN_BUS_H
#define HW_XEN_BUS_H
#include "hw/xen/xen_common.h"
#include "hw/sysbus.h"
#include "qemu/notify.h"
typedef void (*XenWatchHandler)(void *opaque);
typedef struct XenWatch XenWatch;
typedef struct XenEventChannel XenEventChannel;
typedef struct XenDevice {
DeviceState qdev;
domid_t frontend_id;
char *name;
char *backend_path, *frontend_path;
enum xenbus_state backend_state, frontend_state;
Notifier exit;
XenWatch *backend_state_watch, *frontend_state_watch;
bool backend_online;
XenWatch *backend_online_watch;
xengnttab_handle *xgth;
bool feature_grant_copy;
QLIST_HEAD(, XenEventChannel) event_channels;
} XenDevice;
typedef char *(*XenDeviceGetName)(XenDevice *xendev, Error **errp);
typedef void (*XenDeviceRealize)(XenDevice *xendev, Error **errp);
typedef void (*XenDeviceFrontendChanged)(XenDevice *xendev,
enum xenbus_state frontend_state,
Error **errp);
typedef void (*XenDeviceUnrealize)(XenDevice *xendev, Error **errp);
typedef struct XenDeviceClass {
/*< private >*/
DeviceClass parent_class;
/*< public >*/
const char *backend;
const char *device;
XenDeviceGetName get_name;
XenDeviceRealize realize;
XenDeviceFrontendChanged frontend_changed;
XenDeviceUnrealize unrealize;
} XenDeviceClass;
#define TYPE_XEN_DEVICE "xen-device"
#define XEN_DEVICE(obj) \
OBJECT_CHECK(XenDevice, (obj), TYPE_XEN_DEVICE)
#define XEN_DEVICE_CLASS(class) \
OBJECT_CLASS_CHECK(XenDeviceClass, (class), TYPE_XEN_DEVICE)
#define XEN_DEVICE_GET_CLASS(obj) \
OBJECT_GET_CLASS(XenDeviceClass, (obj), TYPE_XEN_DEVICE)
typedef struct XenBus {
BusState qbus;
domid_t backend_id;
struct xs_handle *xsh;
NotifierList watch_notifiers;
XenWatch *backend_watch;
} XenBus;
typedef struct XenBusClass {
/*< private >*/
BusClass parent_class;
} XenBusClass;
#define TYPE_XEN_BUS "xen-bus"
#define XEN_BUS(obj) \
OBJECT_CHECK(XenBus, (obj), TYPE_XEN_BUS)
#define XEN_BUS_CLASS(class) \
OBJECT_CLASS_CHECK(XenBusClass, (class), TYPE_XEN_BUS)
#define XEN_BUS_GET_CLASS(obj) \
OBJECT_GET_CLASS(XenBusClass, (obj), TYPE_XEN_BUS)
void xen_bus_init(void);
void xen_device_backend_set_state(XenDevice *xendev,
enum xenbus_state state);
enum xenbus_state xen_device_backend_get_state(XenDevice *xendev);
void xen_device_backend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
GCC_FMT_ATTR(3, 4);
void xen_device_frontend_printf(XenDevice *xendev, const char *key,
const char *fmt, ...)
GCC_FMT_ATTR(3, 4);
int xen_device_frontend_scanf(XenDevice *xendev, const char *key,
const char *fmt, ...);
void xen_device_set_max_grant_refs(XenDevice *xendev, unsigned int nr_refs,
Error **errp);
void *xen_device_map_grant_refs(XenDevice *xendev, uint32_t *refs,
unsigned int nr_refs, int prot,
Error **errp);
void xen_device_unmap_grant_refs(XenDevice *xendev, void *map,
unsigned int nr_refs, Error **errp);
typedef struct XenDeviceGrantCopySegment {
union {
void *virt;
struct {
uint32_t ref;
off_t offset;
} foreign;
} source, dest;
size_t len;
} XenDeviceGrantCopySegment;
void xen_device_copy_grant_refs(XenDevice *xendev, bool to_domain,
XenDeviceGrantCopySegment segs[],
unsigned int nr_segs, Error **errp);
typedef bool (*XenEventHandler)(void *opaque);
XenEventChannel *xen_device_bind_event_channel(XenDevice *xendev,
AioContext *ctx,
unsigned int port,
XenEventHandler handler,
void *opaque, Error **errp);
void xen_device_notify_event_channel(XenDevice *xendev,
XenEventChannel *channel,
Error **errp);
void xen_device_unbind_event_channel(XenDevice *xendev,
XenEventChannel *channel,
Error **errp);
#endif /* HW_XEN_BUS_H */