Device driver supporting the vending of block storage from a FreeBSD domain to other domains. More...

#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/devicestat.h>
#include <sys/disk.h>
#include <sys/fcntl.h>
#include <sys/filedesc.h>
#include <sys/kdb.h>
#include <sys/module.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/rman.h>
#include <sys/taskqueue.h>
#include <sys/types.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <sys/bitstring.h>
#include <sys/sdt.h>
#include <geom/geom.h>
#include <machine/_inttypes.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <xen/xen-os.h>
#include <xen/blkif.h>
#include <xen/gnttab.h>
#include <xen/xen_intr.h>
#include <contrib/xen/event_channel.h>
#include <contrib/xen/grant_table.h>
#include <xen/xenbus/xenbusvar.h>

Include dependency graph for blkback.c:

Go to the source code of this file.

Data Structures
struct	xbb_xen_reqlist

struct	xbb_xen_req
	Object tracking an in-flight I/O from a Xen VBD consumer. More...

struct	xbb_ring_config
	Configuration data for the shared memory request ring used to communicate with the front-end client of this this driver. More...

struct	xbb_sg
	Structure used to memoize information about a per-request scatter-gather list. More...

struct	xbb_dev_data

struct	xbb_file_data

union	xbb_backend_data

struct	xbb_softc

Macros
#define	XBB_MAX_RING_PAGES 32

#define	XBB_MAX_REQUESTS __CONST_RING_SIZE(blkif, PAGE_SIZE * XBB_MAX_RING_PAGES)

#define	XBB_USE_BOUNCE_BUFFERS
	Define to force all I/O to be performed on memory owned by the backend device, with a copy-in/out to the remote domain's memory. More...

#define	DPRINTF(fmt, args...) do {} while(0)

#define	XBB_MAX_REQUEST_SIZE MIN(128 * 1024, BLKIF_MAX_SEGMENTS_PER_REQUEST * PAGE_SIZE)

#define	XBB_MAX_SEGMENTS_PER_REQUEST

#define	XBB_MAX_SEGMENTS_PER_REQLIST XBB_MAX_SEGMENTS_PER_REQUEST

Typedefs
typedef int(*	xbb_dispatch_t) (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist, int operation, int flags)

Enumerations
enum	xbb_reqlist_flags { XBB_REQLIST_NONE = 0x00 , XBB_REQLIST_MAPPED = 0x01 }

enum	xbb_flag_t { XBBF_READ_ONLY = 0x01 , XBBF_RING_CONNECTED = 0x02 , XBBF_RESOURCE_SHORTAGE = 0x04 , XBBF_SHUTDOWN = 0x08 , XBBF_IN_SHUTDOWN = 0x10 }

enum	xbb_type { XBB_TYPE_NONE = 0x00 , XBB_TYPE_DISK = 0x01 , XBB_TYPE_FILE = 0x02 }

Functions
	__FBSDID ("$FreeBSD$")

static	MALLOC_DEFINE (M_XENBLOCKBACK, "xbbd", "Xen Block Back Driver Data")
	Define to enable rudimentary request logging to the console. More...

static void	xbb_attach_failed (struct xbb_softc xbb, int err, const char fmt,...) __attribute__((format(printf

static void static int	xbb_shutdown (struct xbb_softc *xbb)

	STAILQ_HEAD (xbb_xen_req_list, xbb_xen_req)

	STAILQ_HEAD (xbb_xen_reqlist_list, xbb_xen_reqlist)

	SLIST_HEAD (xbb_xen_req_slist, xbb_xen_req)

static struct xbb_xen_req *	xbb_get_req (struct xbb_softc *xbb)

static void	xbb_release_req (struct xbb_softc xbb, struct xbb_xen_req req)

static void	xbb_release_reqs (struct xbb_softc xbb, struct xbb_xen_req_list req_list, int nreqs)

static uint8_t *	xbb_reqlist_vaddr (struct xbb_xen_reqlist *reqlist, int pagenr, int sector)

static uint8_t *	xbb_reqlist_bounce_addr (struct xbb_xen_reqlist *reqlist, int pagenr, int sector)

static uint8_t *	xbb_reqlist_ioaddr (struct xbb_xen_reqlist *reqlist, int pagenr, int sector)

static uintptr_t	xbb_get_gntaddr (struct xbb_xen_reqlist *reqlist, int pagenr, int sector)

static uint8_t *	xbb_get_kva (struct xbb_softc *xbb, int nr_pages)

static void	xbb_free_kva (struct xbb_softc xbb, uint8_t kva_ptr, int nr_pages)

static void	xbb_unmap_reqlist (struct xbb_xen_reqlist *reqlist)

static struct xbb_xen_reqlist *	xbb_get_reqlist (struct xbb_softc *xbb)

static void	xbb_release_reqlist (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist, int wakeup)

static int	xbb_get_resources (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist, blkif_request_t ring_req, RING_IDX ring_idx)

static void	xbb_queue_response (struct xbb_softc xbb, struct xbb_xen_req req, int status)

static void	xbb_push_responses (struct xbb_softc xbb, int run_taskqueue, int *notify)

static void	xbb_complete_reqlist (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist)

static void	xbb_bio_done (struct bio *bio)

static int	xbb_dispatch_io (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist)

static __inline int	xbb_count_sects (blkif_request_t *ring_req)

static void	xbb_run_queue (void *context, int pending)

static int	xbb_filter (void *arg)

	SDT_PROVIDER_DEFINE (xbb)

	SDT_PROBE_DEFINE1 (xbb, kernel, xbb_dispatch_dev, flush, "int")

	SDT_PROBE_DEFINE3 (xbb, kernel, xbb_dispatch_dev, read, "int", "uint64_t", "uint64_t")

	SDT_PROBE_DEFINE3 (xbb, kernel, xbb_dispatch_dev, write, "int", "uint64_t", "uint64_t")

static int	xbb_dispatch_dev (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist, int operation, int bio_flags)

	SDT_PROBE_DEFINE1 (xbb, kernel, xbb_dispatch_file, flush, "int")

	SDT_PROBE_DEFINE3 (xbb, kernel, xbb_dispatch_file, read, "int", "uint64_t", "uint64_t")

	SDT_PROBE_DEFINE3 (xbb, kernel, xbb_dispatch_file, write, "int", "uint64_t", "uint64_t")

static int	xbb_dispatch_file (struct xbb_softc xbb, struct xbb_xen_reqlist reqlist, int operation, int flags)

static void	xbb_close_backend (struct xbb_softc *xbb)

static int	xbb_open_dev (struct xbb_softc *xbb)

static int	xbb_open_file (struct xbb_softc *xbb)

static int	xbb_open_backend (struct xbb_softc *xbb)

static void	xbb_free_communication_mem (struct xbb_softc *xbb)

static int	xbb_disconnect (struct xbb_softc *xbb)

static int	xbb_connect_ring (struct xbb_softc *xbb)

static int	xbb_alloc_communication_mem (struct xbb_softc *xbb)

static int	xbb_collect_frontend_info (struct xbb_softc *xbb)

static int	xbb_alloc_requests (struct xbb_softc *xbb)

static int	xbb_alloc_request_lists (struct xbb_softc *xbb)

static int	xbb_publish_backend_info (struct xbb_softc *xbb)

static void	xbb_connect (struct xbb_softc *xbb)

static int	xbb_probe (device_t dev)

static void	xbb_setup_sysctl (struct xbb_softc *xbb)

static void	xbb_attach_disk (device_t dev)

static void	xbb_attach_cb (struct xs_watch watch, const char *vec, unsigned int len)

static int	xbb_attach (device_t dev)

static int	xbb_detach (device_t dev)

static int	xbb_suspend (device_t dev)

static int	xbb_resume (device_t dev)

static void	xbb_frontend_changed (device_t dev, XenbusState frontend_state)

	DRIVER_MODULE (xbbd, xenbusb_back, xbb_driver, xbb_devclass, 0, 0)

Variables
static device_method_t	xbb_methods []

static driver_t	xbb_driver

devclass_t	xbb_devclass

Detailed Description

Device driver supporting the vending of block storage from a FreeBSD domain to other domains.

Definition in file blkback.c.

Macro Definition Documentation

◆ DPRINTF

#define DPRINTF	(	fmt,
		args...
	)	do {} while(0)

Definition at line 140 of file blkback.c.

◆ XBB_MAX_REQUEST_SIZE

#define XBB_MAX_REQUEST_SIZE MIN(128 * 1024, BLKIF_MAX_SEGMENTS_PER_REQUEST * PAGE_SIZE)

The maximum mapped region size per request we will allow in a negotiated block-front/back communication channel. Use old default of MAXPHYS == 128K.

Definition at line 148 of file blkback.c.

◆ XBB_MAX_REQUESTS

#define XBB_MAX_REQUESTS __CONST_RING_SIZE(blkif, PAGE_SIZE * XBB_MAX_RING_PAGES)

The maximum number of outstanding request blocks (request headers plus additional segment blocks) we will allow in a negotiated block-front/back communication channel.

Definition at line 101 of file blkback.c.

◆ XBB_MAX_RING_PAGES

#define XBB_MAX_RING_PAGES 32

The maximum number of shared memory ring pages we will allow in a negotiated block-front/back communication channel. Allow enough ring space for all requests to be XBB_MAX_REQUEST_SIZE'd.

Definition at line 94 of file blkback.c.

◆ XBB_MAX_SEGMENTS_PER_REQLIST

#define XBB_MAX_SEGMENTS_PER_REQLIST XBB_MAX_SEGMENTS_PER_REQUEST

The maximum number of ring pages that we can allow per request list. We limit this to the maximum number of segments per request, because that is already a reasonable number of segments to aggregate. This number should never be smaller than XBB_MAX_SEGMENTS_PER_REQUEST, because that would leave situations where we can't dispatch even one large request.

Definition at line 169 of file blkback.c.

◆ XBB_MAX_SEGMENTS_PER_REQUEST

#define XBB_MAX_SEGMENTS_PER_REQUEST

Value:

        (MIN(UIO_MAXIOV,                                        \
             MIN(BLKIF_MAX_SEGMENTS_PER_REQUEST,                \
                 (XBB_MAX_REQUEST_SIZE / PAGE_SIZE) + 1)))

The maximum number of segments (within a request header and accompanying segment blocks) per request we will allow in a negotiated block-front/back communication channel.

Definition at line 156 of file blkback.c.

◆ XBB_USE_BOUNCE_BUFFERS

#define XBB_USE_BOUNCE_BUFFERS

Define to force all I/O to be performed on memory owned by the backend device, with a copy-in/out to the remote domain's memory.

Note: This option is currently required when this driver's domain is operating in HVM mode on a system using an IOMMU.

This driver uses Xen's grant table API to gain access to the memory of the remote domains it serves. When our domain is operating in PV mode, the grant table mechanism directly updates our domain's page table entries to point to the physical pages of the remote domain. This scheme guarantees that blkback and the backing devices it uses can safely perform DMA operations to satisfy requests. In HVM mode, Xen may use a HW IOMMU to insure that our domain cannot DMA to pages owned by another domain. As of Xen 4.0, IOMMU mappings for HVM guests are not updated via the grant table API. For this reason, in HVM mode, we must bounce all requests into memory that is mapped into our domain at domain startup and thus has valid IOMMU mappings.

Definition at line 123 of file blkback.c.

Typedef Documentation

◆ xbb_dispatch_t

typedef int(* xbb_dispatch_t) (struct xbb_softc *xbb, struct xbb_xen_reqlist *reqlist, int operation, int flags)

Function signature of backend specific I/O handlers.

Definition at line 540 of file blkback.c.

Enumeration Type Documentation

◆ xbb_flag_t

enum xbb_flag_t

Per-instance connection state flags.

Enumerator
XBBF_READ_ONLY	The front-end requested a read-only mount of the back-end device/file.
XBBF_RING_CONNECTED	Communication with the front-end has been established.
XBBF_RESOURCE_SHORTAGE	Front-end requests exist in the ring and are waiting for xbb_xen_req objects to free up.
XBBF_SHUTDOWN	Connection teardown in progress.
XBBF_IN_SHUTDOWN	A thread is already performing shutdown processing.

Definition at line 403 of file blkback.c.

◆ xbb_reqlist_flags

enum xbb_reqlist_flags

Enumerator
XBB_REQLIST_NONE
XBB_REQLIST_MAPPED

Definition at line 183 of file blkback.c.

◆ xbb_type

enum xbb_type

Backend device type.

Enumerator
XBB_TYPE_NONE	Backend type unknown.
XBB_TYPE_DISK	Backend type disk (access via cdev switch strategy routine).
XBB_TYPE_FILE	Backend type file (access vnode operations.).

Definition at line 428 of file blkback.c.

Function Documentation

◆ __FBSDID()

__FBSDID ( "$FreeBSD$" )

◆ DRIVER_MODULE()

DRIVER_MODULE	(	xbbd	,
		xenbusb_back	,
		xbb_driver	,
		xbb_devclass	,
		0	,
		0
	)

◆ MALLOC_DEFINE()

static MALLOC_DEFINE	(	M_XENBLOCKBACK	,
		"xbbd"	,
		"Xen Block Back Driver Data"
	)

static

Define to enable rudimentary request logging to the console.

Custom malloc type for all driver allocations.

◆ SDT_PROBE_DEFINE1() [1/2]

SDT_PROBE_DEFINE1	(	xbb	,
		kernel	,
		xbb_dispatch_dev	,
		flush	,
		"int"
	)

◆ SDT_PROBE_DEFINE1() [2/2]

SDT_PROBE_DEFINE1	(	xbb	,
		kernel	,
		xbb_dispatch_file	,
		flush	,
		"int"
	)

◆ SDT_PROBE_DEFINE3() [1/4]

SDT_PROBE_DEFINE3	(	xbb	,
		kernel	,
		xbb_dispatch_dev	,
		read	,
		"int"	,
		"uint64_t"	,
		"uint64_t"
	)

◆ SDT_PROBE_DEFINE3() [2/4]

SDT_PROBE_DEFINE3	(	xbb	,
		kernel	,
		xbb_dispatch_dev	,
		write	,
		"int"	,
		"uint64_t"	,
		"uint64_t"
	)

◆ SDT_PROBE_DEFINE3() [3/4]

SDT_PROBE_DEFINE3	(	xbb	,
		kernel	,
		xbb_dispatch_file	,
		read	,
		"int"	,
		"uint64_t"	,
		"uint64_t"
	)

◆ SDT_PROBE_DEFINE3() [4/4]

SDT_PROBE_DEFINE3	(	xbb	,
		kernel	,
		xbb_dispatch_file	,
		write	,
		"int"	,
		"uint64_t"	,
		"uint64_t"
	)

◆ SDT_PROVIDER_DEFINE()

SDT_PROVIDER_DEFINE ( xbb )

◆ SLIST_HEAD()

SLIST_HEAD	(	xbb_xen_req_slist	,
		xbb_xen_req
	)

◆ STAILQ_HEAD() [1/2]

STAILQ_HEAD	(	xbb_xen_req_list	,
		xbb_xen_req
	)

◆ STAILQ_HEAD() [2/2]

STAILQ_HEAD	(	xbb_xen_reqlist_list	,
		xbb_xen_reqlist
	)

◆ xbb_alloc_communication_mem()

static int xbb_alloc_communication_mem ( struct xbb_softc * xbb )

static

Size KVA and pseudo-physical address allocations based on negotiated values for the size and number of I/O requests, and the size of our communication ring.

Parameters

xbb	Per-instance xbb configuration structure.

These address spaces are used to dynamically map pages in the front-end's domain into our own.

Definition at line 2987 of file blkback.c.

References xbb_softc::dev, DPRINTF, xbb_softc::gnt_base_addr, xbb_softc::kva, xbb_softc::kva_free, xbb_softc::kva_size, xbb_softc::max_request_segments, xbb_softc::max_requests, xbb_softc::pseudo_phys_res, xbb_softc::pseudo_phys_res_id, xbb_softc::reqlist_kva_pages, xbb_softc::reqlist_kva_size, xbb_softc::ring_config, xbb_ring_config::ring_pages, and xenmem_alloc().

Referenced by xbb_connect().

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◆ xbb_alloc_request_lists()

static int xbb_alloc_request_lists ( struct xbb_softc * xbb )

static

Definition at line 3187 of file blkback.c.

References xbb_xen_reqlist::bounce, xbb_softc::dev, xbb_xen_reqlist::gnt_handles, xbb_softc::max_reqlist_segments, xbb_softc::max_reqlist_size, xbb_softc::max_requests, xbb_softc::reqlist_free_stailq, xbb_softc::reqlist_pending_stailq, xbb_softc::request_lists, and xbb_xen_reqlist::xbb.

Referenced by xbb_connect().

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◆ xbb_alloc_requests()

static int xbb_alloc_requests ( struct xbb_softc * xbb )

static

Allocate per-request data structures given request size and number information negotiated with the front-end.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 3160 of file blkback.c.

References xbb_softc::dev, xbb_softc::max_requests, xbb_softc::request_free_stailq, and xbb_softc::requests.

Referenced by xbb_connect().

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◆ xbb_attach()

static int xbb_attach ( device_t dev )

static

Attach to a XenBus device that has been claimed by our probe routine.

Parameters

dev	NewBus device object representing this Xen Block Back instance.

Returns: 0 for success, errno codes for failure.

Definition at line 3718 of file blkback.c.

References xbb_softc::dev, DPRINTF, xbb_softc::hotplug_done, xbb_softc::hotplug_watch, xbb_softc::io_task, xbb_softc::lock, xbb_softc::otherend_id, xbb_attach_cb(), xbb_attach_disk(), xbb_attach_failed(), XBB_MAX_RING_PAGES, xbb_run_queue(), xs_join(), xs_printf(), and xs_register_watch().

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◆ xbb_attach_cb()

static void xbb_attach_cb	(	struct xs_watch *	watch,
		const char **	vec,
		unsigned int	len
	)

static

Definition at line 3674 of file blkback.c.

References xbb_softc::dev, xbb_softc::dev_mode, xbb_softc::dev_name, xbb_softc::dev_type, xbb_softc::hotplug_done, xbb_attach_disk(), xbb_attach_failed(), xs_gather(), and xs_unregister_watch().

Referenced by xbb_attach().

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◆ xbb_attach_disk()

static void xbb_attach_disk ( device_t dev )

static

Definition at line 3597 of file blkback.c.

References xbb_softc::dev, xbb_softc::dev_mode, xbb_softc::dev_name, xbb_softc::flags, xbb_softc::hotplug_done, xbb_softc::io_taskqueue, xbb_softc::sector_size, xbb_attach_failed(), xbb_connect(), xbb_open_backend(), xbb_setup_sysctl(), xbb_softc::xbb_stats, xbb_softc::xbb_stats_in, XBBF_READ_ONLY, and xs_printf().

Referenced by xbb_attach(), and xbb_attach_cb().

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◆ xbb_attach_failed()

static void xbb_attach_failed	(	struct xbb_softc *	xbb,
		int	err,
		const char *	fmt,
			...
	)

static

Report an attach time error to the console and Xen, and cleanup this instance by forcing immediate detach processing.

Parameters

xbb	Per-instance xbb configuration structure.
err	Errno describing the error.
fmt	Printf style format and arguments

Definition at line 3461 of file blkback.c.

References xbb_softc::dev, xbb_softc::lock, xbb_shutdown(), xs_printf(), and xs_vprintf().

Referenced by xbb_attach(), xbb_attach_cb(), and xbb_attach_disk().

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◆ xbb_bio_done()

static void xbb_bio_done ( struct bio * bio )

static

Completion handler for buffer I/O requests issued by the device backend driver.

Parameters

bio	The buffer I/O request on which to perform completion processing.

Definition at line 1469 of file blkback.c.

References xbb_xen_reqlist::bounce, xbb_softc::dev, xbb_softc::dev_name, DPRINTF, xbb_xen_reqlist::kva, xbb_xen_reqlist::pendcnt, xbb_xen_reqlist::residual_512b_sectors, xbb_xen_reqlist::status, xbb_xen_reqlist::xbb, and xbb_complete_reqlist().

Referenced by xbb_dispatch_dev().

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◆ xbb_close_backend()

static void xbb_close_backend ( struct xbb_softc * xbb )

static

Close and cleanup any backend device/file specific state for this block back instance.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 2469 of file blkback.c.

References xbb_softc::backend, xbb_dev_data::cdev, xbb_file_data::cred, xbb_dev_data::csw, xbb_backend_data::dev, xbb_softc::dev_name, xbb_dev_data::dev_ref, xbb_softc::device_type, DPRINTF, xbb_backend_data::file, xbb_softc::flags, xbb_softc::vn, XBB_TYPE_DISK, XBB_TYPE_FILE, XBB_TYPE_NONE, and XBBF_READ_ONLY.

Referenced by xbb_detach(), and xbb_open_backend().

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◆ xbb_collect_frontend_info()

static int xbb_collect_frontend_info ( struct xbb_softc * xbb )

static

Collect front-end information from the XenStore.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 3029 of file blkback.c.

References xbb_softc::abi, xbb_softc::dev, xbb_ring_config::evtchn, xbb_softc::max_request_segments, xbb_softc::max_request_size, xbb_softc::max_requests, xbb_softc::ring_config, xbb_ring_config::ring_pages, xbb_ring_config::ring_ref, XBB_MAX_RING_PAGES, xs_gather(), and xs_scanf().

Referenced by xbb_connect().

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◆ xbb_complete_reqlist()

static void xbb_complete_reqlist	(	struct xbb_softc *	xbb,
		struct xbb_xen_reqlist *	reqlist
	)

static

Complete a request list.

Parameters

xbb	Per-instance xbb configuration structure.
reqlist	Allocated internal request list structure.

Definition at line 1388 of file blkback.c.

References xbb_xen_reqlist::contig_req_list, xbb_xen_reqlist::ds_t0, xbb_xen_reqlist::ds_tag_type, xbb_xen_reqlist::ds_trans_type, xbb_xen_reqlist::flags, xbb_softc::io_task, xbb_softc::io_taskqueue, xbb_softc::lock, notify(), xbb_xen_reqlist::residual_512b_sectors, xbb_xen_reqlist::status, xbb_push_responses(), xbb_queue_response(), xbb_release_reqlist(), XBB_REQLIST_MAPPED, xbb_softc::xbb_stats, xbb_softc::xbb_stats_in, xbb_unmap_reqlist(), and xbb_softc::xen_intr_handle.

Referenced by xbb_bio_done(), xbb_dispatch_file(), and xbb_dispatch_io().

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◆ xbb_connect()

static void xbb_connect ( struct xbb_softc * xbb )

static

Connect to our blkfront peer now that it has completed publishing its configuration into the XenStore.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 3308 of file blkback.c.

References xbb_softc::dev, xbb_softc::flags, xbb_softc::hotplug_done, xbb_softc::max_reqlist_segments, xbb_softc::max_reqlist_size, xbb_softc::max_request_segments, xbb_softc::max_requests, xbb_alloc_communication_mem(), xbb_alloc_request_lists(), xbb_alloc_requests(), xbb_collect_frontend_info(), xbb_connect_ring(), xbb_disconnect(), XBB_MAX_SEGMENTS_PER_REQLIST, and xbb_publish_backend_info().

Referenced by xbb_attach_disk(), and xbb_frontend_changed().

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◆ xbb_connect_ring()

static int xbb_connect_ring ( struct xbb_softc * xbb )

static

Map shared memory ring into domain local address space, initialize ring control structures, and bind an interrupt to the event channel used to notify us of ring changes.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 2854 of file blkback.c.

References xbb_softc::abi, xbb_ring_config::bus_addr, xbb_softc::dev, DPRINTF, xbb_ring_config::evtchn, xbb_softc::flags, xbb_ring_config::gnt_addr, xbb_softc::gnt_base_addr, xbb_ring_config::handle, xbb_softc::kva, xbb_softc::kva_size, xbb_softc::otherend_id, xbb_softc::ring_config, xbb_ring_config::ring_pages, xbb_ring_config::ring_ref, xbb_softc::rings, xbb_ring_config::va, xbb_disconnect(), xbb_filter(), XBB_MAX_RING_PAGES, XBBF_RING_CONNECTED, and xbb_softc::xen_intr_handle.

Referenced by xbb_connect().

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◆ xbb_count_sects()

static __inline int xbb_count_sects ( blkif_request_t * ring_req )

static

Definition at line 1785 of file blkback.c.

Referenced by xbb_run_queue().

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◆ xbb_detach()

static int xbb_detach ( device_t dev )

static

Detach from a block back device instance.

Parameters

dev	NewBus device object representing this Xen Block Back instance.

Returns: 0 for success, errno codes for failure.

Note: A block back device may be detached at any time in its life-cycle, including part way through the attach process. For this reason, initialization order and the initialization state checks in this routine must be carefully coupled so that attach time failures are gracefully handled.

Definition at line 3816 of file blkback.c.

References xbb_softc::dev, xbb_softc::dev_mode, xbb_softc::dev_name, xbb_softc::dev_type, DPRINTF, xbb_softc::io_taskqueue, xbb_softc::lock, xbb_close_backend(), xbb_shutdown(), xbb_softc::xbb_stats, and xbb_softc::xbb_stats_in.

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◆ xbb_disconnect()

static int xbb_disconnect ( struct xbb_softc * xbb )

static

Cleanup all inter-domain communication mechanisms.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 2775 of file blkback.c.

References xbb_softc::active_request_count, xbb_xen_reqlist::bounce, xbb_ring_config::bus_addr, DPRINTF, xbb_softc::flags, xbb_ring_config::gnt_addr, xbb_xen_reqlist::gnt_handles, xbb_ring_config::handle, xbb_softc::io_task, xbb_softc::io_taskqueue, xbb_softc::lock, xbb_softc::request_lists, xbb_softc::requests, xbb_softc::ring_config, xbb_ring_config::ring_pages, xbb_xen_reqlist::xbb, xbb_free_communication_mem(), XBB_MAX_RING_PAGES, XBBF_RING_CONNECTED, and xbb_softc::xen_intr_handle.

Referenced by xbb_connect(), xbb_connect_ring(), and xbb_shutdown().

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◆ xbb_dispatch_dev()

static int xbb_dispatch_dev	(	struct xbb_softc *	xbb,
		struct xbb_xen_reqlist *	reqlist,
		int	operation,
		int	bio_flags
	)

static

Backend handler for character device access.

Parameters

xbb	Per-instance xbb configuration structure.
reqlist	Allocated internal request list structure.
operation	BIO_* I/O operation code.
bio_flags	Additional bio_flag data to pass to any generated bios (e.g. BIO_ORDERED)..

Returns: 0 for success, errno codes for failure.

Definition at line 2059 of file blkback.c.

References xbb_softc::backend, xbb_xen_reqlist::bounce, xbb_dev_data::cdev, xbb_dev_data::csw, xbb_backend_data::dev, xbb_softc::dev, DPRINTF, xbb_sg::first_sect, xbb_xen_reqlist::kva, xbb_sg::last_sect, xbb_xen_reqlist::nr_segments, xbb_sg::nsect, xbb_softc::otherend_id, xbb_xen_reqlist::pendcnt, xbb_softc::sector_size, xbb_softc::sector_size_shift, xbb_xen_reqlist::starting_sector_number, xbb_bio_done(), xbb_dispatch_dev(), XBB_MAX_SEGMENTS_PER_REQLIST, xbb_reqlist_ioaddr(), and xbb_softc::xbb_sgs.

Referenced by xbb_dispatch_dev(), and xbb_open_dev().

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◆ xbb_dispatch_file()

static int xbb_dispatch_file	(	struct xbb_softc *	xbb,
		struct xbb_xen_reqlist *	reqlist,
		int	operation,
		int	flags
	)

static

Backend handler for file access.

Parameters

xbb	Per-instance xbb configuration structure.
reqlist	Allocated internal request list.
operation	BIO_* I/O operation code.
flags	Additional bio_flag data to pass to any generated bios (e.g. BIO_ORDERED)..

Returns: 0 for success, errno codes for failure.

Definition at line 2235 of file blkback.c.

References xbb_softc::backend, xbb_file_data::cred, xbb_softc::dev, xbb_backend_data::file, xbb_sg::first_sect, xbb_sg::last_sect, xbb_xen_reqlist::nr_segments, xbb_sg::nsect, xbb_file_data::saved_xiovecs, xbb_softc::sector_size_shift, xbb_xen_reqlist::starting_sector_number, xbb_xen_reqlist::status, xbb_softc::vn, xbb_complete_reqlist(), xbb_dispatch_file(), xbb_reqlist_ioaddr(), xbb_reqlist_vaddr(), xbb_softc::xbb_sgs, xbb_file_data::xiovecs, and xbb_file_data::xiovecs_vaddr.

Referenced by xbb_dispatch_file(), and xbb_open_file().

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◆ xbb_dispatch_io()

static int xbb_dispatch_io	(	struct xbb_softc *	xbb,
		struct xbb_xen_reqlist *	reqlist
	)

static

Parse a blkif request into an internal request structure and send it to the backend for processing.

Parameters

xbb	Per-instance xbb configuration structure.
reqlist	Allocated internal request list structure.

Returns: On success, 0. For resource shortages, non-zero.

This routine performs the backend common aspects of request parsing including compiling an internal request structure, parsing the S/G list and any secondary ring requests in which they may reside, and the mapping of front-end I/O pages into our domain.

Definition at line 1547 of file blkback.c.

References xbb_xen_reqlist::contig_req_list, xbb_softc::dev, xbb_softc::dev_name, xbb_softc::disable_flush, xbb_softc::dispatch_io, DPRINTF, xbb_xen_reqlist::ds_t0, xbb_xen_reqlist::ds_tag_type, xbb_xen_reqlist::ds_trans_type, xbb_sg::first_sect, xbb_xen_reqlist::flags, xbb_softc::flags, xbb_softc::flush_count, xbb_softc::flush_interval, xbb_ring_config::gnt_addr, xbb_xen_reqlist::gnt_handles, xbb_xen_reqlist::kva, xbb_sg::last_sect, xbb_softc::maps, xbb_softc::max_request_segments, xbb_softc::media_num_sectors, xbb_xen_reqlist::nr_segments, xbb_sg::nsect, xbb_xen_reqlist::operation, xbb_softc::otherend_id, xbb_softc::ring_config, xbb_softc::sector_size, xbb_softc::sector_size_shift, xbb_xen_reqlist::starting_sector_number, xbb_xen_reqlist::status, xbb_xen_reqlist::xbb, xbb_complete_reqlist(), xbb_get_gntaddr(), xbb_get_kva(), XBB_MAX_SEGMENTS_PER_REQLIST, XBB_REQLIST_MAPPED, xbb_softc::xbb_sgs, xbb_softc::xbb_stats, and XBBF_READ_ONLY.

Referenced by xbb_run_queue().

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◆ xbb_filter()

static int xbb_filter ( void * arg )

static

Interrupt handler bound to the shared ring's event channel.

Parameters

arg	Callback argument registerd during event channel binding - the xbb_softc for this instance.

Definition at line 2028 of file blkback.c.

References xbb_softc::io_task, and xbb_softc::io_taskqueue.

Referenced by xbb_connect_ring().

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◆ xbb_free_communication_mem()

static void xbb_free_communication_mem ( struct xbb_softc * xbb )

static

Free dynamically allocated KVA or pseudo-physical address allocations.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 2752 of file blkback.c.

References xbb_softc::dev, xbb_softc::gnt_base_addr, xbb_softc::kva, xbb_softc::kva_free, xbb_softc::pseudo_phys_res, xbb_softc::pseudo_phys_res_id, and xenmem_free().

Referenced by xbb_disconnect().

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◆ xbb_free_kva()

static void xbb_free_kva	(	struct xbb_softc *	xbb,
		uint8_t *	kva_ptr,
		int	nr_pages
	)

static

Free allocated KVA.

Parameters

xbb	Per-instance xbb configuration structure.
kva_ptr	Pointer to allocated KVA region.
nr_pages	Number of pages in the KVA region.

Definition at line 1068 of file blkback.c.

References xbb_softc::kva, xbb_softc::kva_free, and xbb_softc::lock.

Referenced by xbb_release_reqlist().

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◆ xbb_frontend_changed()

static void xbb_frontend_changed	(	device_t	dev,
		XenbusState	frontend_state
	)

static

Handle state changes expressed via the XenStore by our front-end peer.

Parameters

dev	NewBus device object representing this Xen Block Back instance.
frontend_state	The new state of the front-end.

Returns: 0 for success, errno codes for failure.

Definition at line 3907 of file blkback.c.

References xbb_softc::dev, DPRINTF, xbb_softc::lock, xbb_connect(), and xbb_shutdown().

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◆ xbb_get_gntaddr()

static uintptr_t xbb_get_gntaddr	(	struct xbb_xen_reqlist *	reqlist,
		int	pagenr,
		int	sector
	)

inlinestatic

Given a page index and 512b sector offset within that page, calculate an offset into the local pseudo-physical address space used to map a front-end's request data into a request.

Parameters

reqlist	The request list structure whose pseudo-physical region will be accessed.
pagenr	The page index used to compute the pseudo-physical offset.
sector	The 512b sector index used to compute the page relative pseudo-physical offset.

Returns: The computed global pseudo-phsyical address.

Depending on configuration, this will either be a local bounce buffer or a pointer to the memory mapped in from the front-end domain for this request.

Definition at line 957 of file blkback.c.

References xbb_softc::gnt_base_addr, xbb_xen_reqlist::kva, xbb_softc::kva, and xbb_xen_reqlist::xbb.

Referenced by xbb_dispatch_io(), and xbb_unmap_reqlist().

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◆ xbb_get_kva()

static uint8_t * xbb_get_kva	(	struct xbb_softc *	xbb,
		int	nr_pages
	)

static

Get Kernel Virtual Address space for mapping requests.

Parameters

xbb	Per-instance xbb configuration structure.
nr_pages	Number of pages needed.
check_only	If set, check for free KVA but don't allocate it.
have_lock	If set, xbb lock is already held.

Returns: On success, a pointer to the allocated KVA region. Otherwise NULL.

Note: This should be unnecessary once we have either chaining or scatter/gather support for struct bio. At that point we'll be able to put multiple addresses and lengths in one bio/bio chain and won't need to map everything into one virtual segment.

Definition at line 984 of file blkback.c.

References xbb_softc::flags, xbb_softc::kva, xbb_softc::kva_free, xbb_softc::kva_shortages, xbb_softc::lock, xbb_softc::reqlist_kva_pages, xbb_softc::ring_config, xbb_ring_config::va, and XBBF_RESOURCE_SHORTAGE.

Referenced by xbb_dispatch_io().

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◆ xbb_get_req()

static struct xbb_xen_req * xbb_get_req ( struct xbb_softc * xbb )

inlinestatic

Allocate an internal transaction tracking structure from the free pool.

Parameters

xbb	Per-instance xbb configuration structure.

Returns: On success, a pointer to the allocated xbb_xen_req structure. Otherwise NULL.

Definition at line 823 of file blkback.c.

References xbb_softc::active_request_count, xbb_softc::lock, and xbb_softc::request_free_stailq.

Referenced by xbb_get_resources().

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◆ xbb_get_reqlist()

static struct xbb_xen_reqlist * xbb_get_reqlist ( struct xbb_softc * xbb )

inlinestatic

Allocate an internal transaction tracking structure from the free pool.

Parameters

xbb	Per-instance xbb configuration structure.

Returns: On success, a pointer to the allocated xbb_xen_reqlist structure. Otherwise NULL.

Definition at line 1118 of file blkback.c.

References xbb_xen_reqlist::contig_req_list, xbb_xen_reqlist::flags, xbb_xen_reqlist::kva, xbb_softc::lock, xbb_xen_reqlist::nr_segments, xbb_xen_reqlist::num_children, xbb_softc::reqlist_free_stailq, xbb_xen_reqlist::residual_512b_sectors, xbb_xen_reqlist::status, xbb_xen_reqlist::xbb, and XBB_REQLIST_NONE.

Referenced by xbb_get_resources().

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◆ xbb_get_resources()

static int xbb_get_resources	(	struct xbb_softc *	xbb,
		struct xbb_xen_reqlist **	reqlist,
		blkif_request_t *	ring_req,
		RING_IDX	ring_idx
	)

static

Request resources and do basic request setup.

Parameters

xbb	Per-instance xbb configuration structure.
reqlist	Pointer to reqlist pointer.
ring_req	Pointer to a block ring request.
ring_index	The ring index of this request.

Returns: 0 for success, non-zero for failure.

Definition at line 1192 of file blkback.c.

References xbb_softc::abi, xbb_softc::flags, xbb_softc::lock, xbb_xen_reqlist::operation, xbb_softc::reqlist_pending_stailq, xbb_softc::request_shortages, xbb_xen_reqlist::starting_sector_number, xbb_get_req(), xbb_get_reqlist(), xbb_release_req(), xbb_release_reqlist(), xbb_softc::xbb_stats_in, XBBF_RESOURCE_SHORTAGE, and XBBF_SHUTDOWN.

Referenced by xbb_run_queue().

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◆ xbb_open_backend()

static int xbb_open_backend ( struct xbb_softc * xbb )

static

Open the backend provider for this connection.

Parameters

xbb	Per-instance xbb configuration structure.

Returns: 0 for success, errno codes for failure.

Definition at line 2661 of file blkback.c.

References xbb_softc::dev, xbb_softc::dev_name, xbb_softc::device_type, DPRINTF, xbb_softc::flags, xbb_softc::media_num_sectors, xbb_softc::media_size, xbb_softc::sector_size, xbb_softc::sector_size_shift, xbb_softc::vn, xbb_close_backend(), xbb_open_dev(), xbb_open_file(), XBB_TYPE_DISK, and XBBF_READ_ONLY.

Referenced by xbb_attach_disk().

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◆ xbb_open_dev()

static int xbb_open_dev ( struct xbb_softc * xbb )

static

Open a character device to be used for backend I/O.

Parameters

xbb	Per-instance xbb configuration structure.

Returns: 0 for success, errno codes for failure.

Definition at line 2525 of file blkback.c.

References xbb_softc::backend, xbb_dev_data::cdev, xbb_dev_data::csw, xbb_backend_data::dev, xbb_softc::dev, xbb_softc::dev_name, xbb_dev_data::dev_ref, xbb_softc::device_type, xbb_softc::dispatch_io, xbb_softc::media_size, xbb_softc::sector_size, xbb_softc::vn, xbb_dispatch_dev(), and XBB_TYPE_DISK.

Referenced by xbb_open_backend().

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◆ xbb_open_file()

static int xbb_open_file ( struct xbb_softc * xbb )

static

Open a file to be used for backend I/O.

Parameters

xbb	Per-instance xbb configuration structure.

Returns: 0 for success, errno codes for failure.

Definition at line 2587 of file blkback.c.

References xbb_softc::backend, xbb_file_data::cred, xbb_softc::dev, xbb_softc::dev_name, xbb_softc::device_type, xbb_softc::dispatch_io, xbb_backend_data::file, xbb_softc::media_size, xbb_softc::sector_size, xbb_softc::vn, xbb_dispatch_file(), and XBB_TYPE_FILE.

Referenced by xbb_open_backend().

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◆ xbb_probe()

static int xbb_probe ( device_t dev )

static

Inspect a XenBus device and claim it if is of the appropriate type.

Parameters

dev	NewBus device object representing a candidate XenBus device.

Returns: 0 for success, errno codes for failure.

Definition at line 3493 of file blkback.c.

◆ xbb_publish_backend_info()

static int xbb_publish_backend_info ( struct xbb_softc * xbb )

static

Supply information about the physical device to the frontend via XenBus.

Parameters

xbb	Per-instance xbb configuration structure.

Definition at line 3249 of file blkback.c.

References xbb_softc::dev, xbb_softc::flags, xbb_softc::media_num_sectors, xbb_softc::sector_size, XBBF_READ_ONLY, xs_printf(), xs_transaction_end(), and xs_transaction_start().

Referenced by xbb_connect().

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◆ xbb_push_responses()

static void xbb_push_responses	(	struct xbb_softc *	xbb,
		int *	run_taskqueue,
		int *	notify
	)

static

Send queued responses to blkif requests.

Parameters

xbb	Per-instance xbb configuration structure.
run_taskqueue	Flag that is set to 1 if the taskqueue should be run, 0 if it does not need to be run.
notify	Flag that is set to 1 if the other end should be notified via irq, 0 if the other end should not be notified.

Definition at line 1351 of file blkback.c.

References xbb_softc::lock, notify(), xbb_softc::reqs_completed, xbb_softc::reqs_queued_for_completion, and xbb_softc::rings.

Referenced by xbb_complete_reqlist().

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◆ xbb_queue_response()

static void xbb_queue_response	(	struct xbb_softc *	xbb,
		struct xbb_xen_req *	req,
		int	status
	)

static

Create and queue a response to a blkif request.

Parameters

xbb	Per-instance xbb configuration structure.
req	The request structure to which to respond.
status	The status code to report. See BLKIF_RSP_* in sys/contrib/xen/io/blkif.h.

Definition at line 1286 of file blkback.c.

References xbb_softc::abi, xbb_softc::lock, xbb_softc::reqs_completed_with_error, xbb_softc::reqs_queued_for_completion, and xbb_softc::rings.

Referenced by xbb_complete_reqlist().

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◆ xbb_release_req()

static void xbb_release_req	(	struct xbb_softc *	xbb,
		struct xbb_xen_req *	req
	)

inlinestatic

Return an allocated transaction tracking structure to the free pool.

Parameters

xbb	Per-instance xbb configuration structure.
req	The request structure to free.

Definition at line 846 of file blkback.c.

References xbb_softc::active_request_count, xbb_softc::lock, and xbb_softc::request_free_stailq.

Referenced by xbb_get_resources().

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◆ xbb_release_reqlist()

static void xbb_release_reqlist	(	struct xbb_softc *	xbb,
		struct xbb_xen_reqlist *	reqlist,
		int	wakeup
	)

inlinestatic

Return an allocated transaction tracking structure to the free pool.

Parameters

xbb	Per-instance xbb configuration structure.
req	The request list structure to free.
wakeup	If set, wakeup the work thread if freeing this reqlist during a resource shortage condition.

Definition at line 1149 of file blkback.c.

References xbb_xen_reqlist::contig_req_list, xbb_softc::flags, xbb_softc::io_task, xbb_softc::io_taskqueue, xbb_xen_reqlist::kva, xbb_softc::lock, xbb_xen_reqlist::nr_segments, xbb_xen_reqlist::num_children, xbb_softc::reqlist_free_stailq, xbb_xen_reqlist::xbb, xbb_free_kva(), xbb_release_reqs(), xbb_shutdown(), XBBF_RESOURCE_SHORTAGE, and XBBF_SHUTDOWN.

Referenced by xbb_complete_reqlist(), and xbb_get_resources().

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◆ xbb_release_reqs()

static void xbb_release_reqs	(	struct xbb_softc *	xbb,
		struct xbb_xen_req_list *	req_list,
		int	nreqs
	)

inlinestatic

Return an xbb_xen_req_list of allocated xbb_xen_reqs to the free pool.

Parameters

xbb	Per-instance xbb configuration structure.
req_list	The list of requests to free.
nreqs	The number of items in the list.

Definition at line 865 of file blkback.c.

References xbb_softc::active_request_count, xbb_softc::lock, and xbb_softc::request_free_stailq.

Referenced by xbb_release_reqlist().

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◆ xbb_reqlist_bounce_addr()

static uint8_t * xbb_reqlist_bounce_addr	(	struct xbb_xen_reqlist *	reqlist,
		int	pagenr,
		int	sector
	)

inlinestatic

Given a page index and 512b sector offset within that page, calculate an offset into a request's local bounce memory region.

Parameters

reqlist	The request structure whose bounce region will be accessed.
pagenr	The page index used to compute the bounce offset.
sector	The 512b sector index used to compute the page relative bounce offset.

Returns: The computed global bounce buffer address.

Definition at line 907 of file blkback.c.

References xbb_xen_reqlist::bounce.

Referenced by xbb_reqlist_ioaddr().

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◆ xbb_reqlist_ioaddr()

static uint8_t * xbb_reqlist_ioaddr	(	struct xbb_xen_reqlist *	reqlist,
		int	pagenr,
		int	sector
	)

inlinestatic

Given a page number and 512b sector offset within that page, calculate an offset into the request's memory region that the underlying backend device/file should use for I/O.

Parameters

reqlist	The request structure whose I/O region will be accessed.
pagenr	The page index used to compute the I/O offset.
sector	The 512b sector index used to compute the page relative I/O offset.

Returns: The computed global I/O address.

Depending on configuration, this will either be a local bounce buffer or a pointer to the memory mapped in from the front-end domain for this request.

Definition at line 930 of file blkback.c.

References xbb_reqlist_bounce_addr(), and xbb_reqlist_vaddr().

Referenced by xbb_dispatch_dev(), and xbb_dispatch_file().

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◆ xbb_reqlist_vaddr()

static uint8_t * xbb_reqlist_vaddr	(	struct xbb_xen_reqlist *	reqlist,
		int	pagenr,
		int	sector
	)

inlinestatic

Given a page index and 512b sector offset within that page, calculate an offset into a request's kva region.

Parameters

reqlist	The request structure whose kva region will be accessed.
pagenr	The page index used to compute the kva offset.
sector	The 512b sector index used to compute the page relative kva offset.

Returns: The computed global KVA offset.

Definition at line 889 of file blkback.c.

References xbb_xen_reqlist::kva.

Referenced by xbb_dispatch_file(), and xbb_reqlist_ioaddr().

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◆ xbb_resume()

static int xbb_resume ( device_t dev )

static

Perform any processing required to recover from a suspended state.

Parameters

dev	NewBus device object representing this Xen Block Back instance.

Returns: 0 for success, errno codes for failure.

Definition at line 3892 of file blkback.c.

◆ xbb_run_queue()

static void xbb_run_queue	(	void *	context,
		int	pending
	)

static

Process incoming requests from the shared communication ring in response to a signal on the ring's event channel.

Parameters

context	Callback argument registerd during task initialization - the xbb_softc for this instance.
pending	The number of taskqueue_enqueue events that have occurred since this handler was last run.

Run so long as there is work to consume and the generation of a response will not overflow the ring.

Note: There's a 1 to 1 relationship between requests and responses, so an overflow should never occur. This test is to protect our domain from digesting bogus data. Shouldn't we log this?

Definition at line 1814 of file blkback.c.

References xbb_softc::abi, xbb_softc::forced_dispatch, xbb_softc::max_reqlist_segments, xbb_xen_reqlist::next_contig_sector, xbb_softc::no_coalesce_reqs, xbb_softc::normal_dispatch, xbb_xen_reqlist::nr_segments, xbb_xen_reqlist::operation, xbb_softc::reqlist_pending_stailq, xbb_softc::reqs_received, xbb_softc::rings, xbb_softc::total_dispatch, xbb_xen_reqlist::xbb, xbb_count_sects(), xbb_dispatch_io(), and xbb_get_resources().

Referenced by xbb_attach().

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◆ xbb_setup_sysctl()

static void xbb_setup_sysctl ( struct xbb_softc * xbb )

static

Setup sysctl variables to control various Block Back parameters.

Parameters

xbb	Xen Block Back softc.

Definition at line 3512 of file blkback.c.

References xbb_softc::dev, xbb_softc::disable_flush, xbb_softc::flush_interval, xbb_softc::forced_dispatch, xbb_softc::kva_shortages, xbb_softc::max_request_segments, xbb_softc::max_request_size, xbb_softc::max_requests, xbb_softc::no_coalesce_reqs, xbb_softc::normal_dispatch, xbb_softc::reqs_completed, xbb_softc::reqs_completed_with_error, xbb_softc::reqs_queued_for_completion, xbb_softc::reqs_received, xbb_softc::request_shortages, xbb_softc::ring_config, xbb_ring_config::ring_pages, and xbb_softc::total_dispatch.

Referenced by xbb_attach_disk().

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◆ xbb_shutdown()

static int xbb_shutdown ( struct xbb_softc * xbb )

static

Perform device shutdown functions.

Parameters

xbb	Per-instance xbb configuration structure.

Mark this instance as shutting down, wait for any active I/O on the backend device/file to drain, disconnect from the front-end, and notify any waiters (e.g. a thread invoking our detach method) that detach can now proceed.

Definition at line 3388 of file blkback.c.

References xbb_softc::dev, DPRINTF, xbb_softc::flags, xbb_softc::hotplug_watch, xbb_softc::lock, xbb_disconnect(), XBBF_IN_SHUTDOWN, XBBF_SHUTDOWN, and xs_unregister_watch().

Referenced by xbb_attach_failed(), xbb_detach(), xbb_frontend_changed(), and xbb_release_reqlist().

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◆ xbb_suspend()

static int xbb_suspend ( device_t dev )

static

Prepare this block back device for suspension of this VM.

Parameters

dev	NewBus device object representing this Xen Block Back instance.

Returns: 0 for success, errno codes for failure.

Definition at line 3870 of file blkback.c.

References xbb_softc::dev.

◆ xbb_unmap_reqlist()

static void xbb_unmap_reqlist ( struct xbb_xen_reqlist * reqlist )

static

Unmap the front-end pages associated with this I/O request.

Parameters

req	The request structure to unmap.

Definition at line 1085 of file blkback.c.

References xbb_xen_reqlist::gnt_handles, xbb_xen_reqlist::nr_segments, xbb_get_gntaddr(), and XBB_MAX_SEGMENTS_PER_REQLIST.

Referenced by xbb_complete_reqlist().

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Variable Documentation

◆ xbb_devclass

devclass_t xbb_devclass

Definition at line 3957 of file blkback.c.

◆ xbb_driver

driver_t xbb_driver

static

Initial value:

= {
        "xbbd",
        xbb_methods,
        sizeof(struct xbb_softc),
}

Definition at line 3952 of file blkback.c.

◆ xbb_methods

device_method_t xbb_methods[]

static

Initial value:

= {
        
        DEVMETHOD(device_probe,         xbb_probe),
        DEVMETHOD(device_attach,        xbb_attach),
        DEVMETHOD(device_detach,        xbb_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),
        DEVMETHOD(device_suspend,       xbb_suspend),
        DEVMETHOD(device_resume,        xbb_resume),
 
        
        DEVMETHOD(xenbus_otherend_changed, xbb_frontend_changed),
        { 0, 0 }
}

Definition at line 3938 of file blkback.c.

Data Structures

Macros

Typedefs

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ DPRINTF

◆ XBB_MAX_REQUEST_SIZE

◆ XBB_MAX_REQUESTS

◆ XBB_MAX_RING_PAGES

◆ XBB_MAX_SEGMENTS_PER_REQLIST

◆ XBB_MAX_SEGMENTS_PER_REQUEST

◆ XBB_USE_BOUNCE_BUFFERS

Typedef Documentation

◆ xbb_dispatch_t

Enumeration Type Documentation

◆ xbb_flag_t

◆ xbb_reqlist_flags

◆ xbb_type

Function Documentation

◆ __FBSDID()

◆ DRIVER_MODULE()

◆ MALLOC_DEFINE()

◆ SDT_PROBE_DEFINE1() [1/2]

◆ SDT_PROBE_DEFINE1() [2/2]

◆ SDT_PROBE_DEFINE3() [1/4]

◆ SDT_PROBE_DEFINE3() [2/4]

◆ SDT_PROBE_DEFINE3() [3/4]

◆ SDT_PROBE_DEFINE3() [4/4]

◆ SDT_PROVIDER_DEFINE()

◆ SLIST_HEAD()

◆ STAILQ_HEAD() [1/2]

◆ STAILQ_HEAD() [2/2]

◆ xbb_alloc_communication_mem()

◆ xbb_alloc_request_lists()

◆ xbb_alloc_requests()

◆ xbb_attach()

◆ xbb_attach_cb()

◆ xbb_attach_disk()

◆ xbb_attach_failed()

◆ xbb_bio_done()

◆ xbb_close_backend()

◆ xbb_collect_frontend_info()

◆ xbb_complete_reqlist()

◆ xbb_connect()

◆ xbb_connect_ring()

◆ xbb_count_sects()

◆ xbb_detach()

◆ xbb_disconnect()

◆ xbb_dispatch_dev()

◆ xbb_dispatch_file()

◆ xbb_dispatch_io()

◆ xbb_filter()

◆ xbb_free_communication_mem()

◆ xbb_free_kva()

◆ xbb_frontend_changed()

◆ xbb_get_gntaddr()

◆ xbb_get_kva()

◆ xbb_get_req()

◆ xbb_get_reqlist()

◆ xbb_get_resources()

◆ xbb_open_backend()

◆ xbb_open_dev()

◆ xbb_open_file()

◆ xbb_probe()

◆ xbb_publish_backend_info()

◆ xbb_push_responses()

◆ xbb_queue_response()

◆ xbb_release_req()

◆ xbb_release_reqlist()

◆ xbb_release_reqs()

◆ xbb_reqlist_bounce_addr()

◆ xbb_reqlist_ioaddr()

◆ xbb_reqlist_vaddr()

◆ xbb_resume()

◆ xbb_run_queue()

◆ xbb_setup_sysctl()

◆ xbb_shutdown()