ff662b5c98
o Add support for backend devices (e.g. blkback)
o Implement extensions to the Xen para-virtualized block API to allow
for larger and more outstanding I/Os.
o Import a completely rewritten block back driver with support for fronting
I/O to both raw devices and files.
o General cleanup and documentation of the XenBus and XenStore support code.
o Robustness and performance updates for the block front driver.
o Fixes to the netfront driver.
Sponsored by: Spectra Logic Corporation
sys/xen/xenbus/init.txt:
Deleted: This file explains the Linux method for XenBus device
enumeration and thus does not apply to FreeBSD's NewBus approach.
sys/xen/xenbus/xenbus_probe_backend.c:
Deleted: Linux version of backend XenBus service routines. It
was never ported to FreeBSD. See xenbusb.c, xenbusb_if.m,
xenbusb_front.c xenbusb_back.c for details of FreeBSD's XenBus
support.
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenbus/xenbus_xs.c:
sys/xen/xenbus/xenbus_comms.c:
sys/xen/xenbus/xenbus_comms.h:
sys/xen/xenstore/xenstorevar.h:
sys/xen/xenstore/xenstore.c:
Split XenStore into its own tree. XenBus is a software layer built
on top of XenStore. The old arrangement and the naming of some
structures and functions blurred these lines making it difficult to
discern what services are provided by which layer and at what times
these services are available (e.g. during system startup and shutdown).
sys/xen/xenbus/xenbus_client.c:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_probe.c:
sys/xen/xenbus/xenbusb.c:
sys/xen/xenbus/xenbusb.h:
Split up XenBus code into methods available for use by client
drivers (xenbus.c) and code used by the XenBus "bus code" to
enumerate, attach, detach, and service bus drivers.
sys/xen/reboot.c:
sys/dev/xen/control/control.c:
Add a XenBus front driver for handling shutdown, reboot, suspend, and
resume events published in the XenStore. Move all PV suspend/reboot
support from reboot.c into this driver.
sys/xen/blkif.h:
New file from Xen vendor with macros and structures used by
a block back driver to service requests from a VM running a
different ABI (e.g. amd64 back with i386 front).
sys/conf/files:
Adjust kernel build spec for new XenBus/XenStore layout and added
Xen functionality.
sys/dev/xen/balloon/balloon.c:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/blkfront/blkfront.c:
sys/xen/xenbus/...
sys/xen/xenstore/...
o Rename XenStore APIs and structures from xenbus_* to xs_*.
o Adjust to use of M_XENBUS and M_XENSTORE malloc types for allocation
of objects returned by these APIs.
o Adjust for changes in the bus interface for Xen drivers.
sys/xen/xenbus/...
sys/xen/xenstore/...
Add Doxygen comments for these interfaces and the code that
implements them.
sys/dev/xen/blkback/blkback.c:
o Rewrite the Block Back driver to attach properly via newbus,
operate correctly in both PV and HVM mode regardless of domain
(e.g. can be in a DOM other than 0), and to deal with the latest
metadata available in XenStore for block devices.
o Allow users to specify a file as a backend to blkback, in addition
to character devices. Use the namei lookup of the backend path
to automatically configure, based on file type, the appropriate
backend method.
The current implementation is limited to a single outstanding I/O
at a time to file backed storage.
sys/dev/xen/blkback/blkback.c:
sys/xen/interface/io/blkif.h:
sys/xen/blkif.h:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
Extend the Xen blkif API: Negotiable request size and number of
requests.
This change extends the information recorded in the XenStore
allowing block front/back devices to negotiate for optimal I/O
parameters. This has been achieved without sacrificing backward
compatibility with drivers that are unaware of these protocol
enhancements. The extensions center around the connection protocol
which now includes these additions:
o The back-end device publishes its maximum supported values for,
request I/O size, the number of page segments that can be
associated with a request, the maximum number of requests that
can be concurrently active, and the maximum number of pages that
can be in the shared request ring. These values are published
before the back-end enters the XenbusStateInitWait state.
o The front-end waits for the back-end to enter either the InitWait
or Initialize state. At this point, the front end limits it's
own capabilities to the lesser of the values it finds published
by the backend, it's own maximums, or, should any back-end data
be missing in the store, the values supported by the original
protocol. It then initializes it's internal data structures
including allocation of the shared ring, publishes its maximum
capabilities to the XenStore and transitions to the Initialized
state.
o The back-end waits for the front-end to enter the Initalized
state. At this point, the back end limits it's own capabilities
to the lesser of the values it finds published by the frontend,
it's own maximums, or, should any front-end data be missing in
the store, the values supported by the original protocol. It
then initializes it's internal data structures, attaches to the
shared ring and transitions to the Connected state.
o The front-end waits for the back-end to enter the Connnected
state, transitions itself to the connected state, and can
commence I/O.
Although an updated front-end driver must be aware of the back-end's
InitWait state, the back-end has been coded such that it can
tolerate a front-end that skips this step and transitions directly
to the Initialized state without waiting for the back-end.
sys/xen/interface/io/blkif.h:
o Increase BLKIF_MAX_SEGMENTS_PER_REQUEST to 255. This is
the maximum number possible without changing the blkif
request header structure (nr_segs is a uint8_t).
o Add two new constants:
BLKIF_MAX_SEGMENTS_PER_HEADER_BLOCK, and
BLKIF_MAX_SEGMENTS_PER_SEGMENT_BLOCK. These respectively
indicate the number of segments that can fit in the first
ring-buffer entry of a request, and for each subsequent
(sg element only) ring-buffer entry associated with the
"header" ring-buffer entry of the request.
o Add the blkif_request_segment_t typedef for segment
elements.
o Add the BLKRING_GET_SG_REQUEST() macro which wraps the
RING_GET_REQUEST() macro and returns a properly cast
pointer to an array of blkif_request_segment_ts.
o Add the BLKIF_SEGS_TO_BLOCKS() macro which calculates the
number of ring entries that will be consumed by a blkif
request with the given number of segments.
sys/xen/blkif.h:
o Update for changes in interface/io/blkif.h macros.
o Update the BLKIF_MAX_RING_REQUESTS() macro to take the
ring size as an argument to allow this calculation on
multi-page rings.
o Add a companion macro to BLKIF_MAX_RING_REQUESTS(),
BLKIF_RING_PAGES(). This macro determines the number of
ring pages required in order to support a ring with the
supplied number of request blocks.
sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
o Negotiate with the other-end with the following limits:
Reqeust Size: MAXPHYS
Max Segments: (MAXPHYS/PAGE_SIZE) + 1
Max Requests: 256
Max Ring Pages: Sufficient to support Max Requests with
Max Segments.
o Dynamically allocate request pools and segemnts-per-request.
o Update ring allocation/attachment code to support a
multi-page shared ring.
o Update routines that access the shared ring to handle
multi-block requests.
sys/dev/xen/blkfront/blkfront.c:
o Track blkfront allocations in a blkfront driver specific
malloc pool.
o Strip out XenStore transaction retry logic in the
connection code. Transactions only need to be used when
the update to multiple XenStore nodes must be atomic.
That is not the case here.
o Fully disable blkif_resume() until it can be fixed
properly (it didn't work before this change).
o Destroy bus-dma objects during device instance tear-down.
o Properly handle backend devices with powef-of-2 sector
sizes larger than 512b.
sys/dev/xen/blkback/blkback.c:
Advertise support for and implement the BLKIF_OP_WRITE_BARRIER
and BLKIF_OP_FLUSH_DISKCACHE blkif opcodes using BIO_FLUSH and
the BIO_ORDERED attribute of bios.
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
Fix various bugs in blkfront.
o gnttab_alloc_grant_references() returns 0 for success and
non-zero for failure. The check for < 0 is a leftover
Linuxism.
o When we negotiate with blkback and have to reduce some of our
capabilities, print out the original and reduced capability before
changing the local capability. So the user now gets the correct
information.
o Fix blkif_restart_queue_callback() formatting. Make sure we hold
the mutex in that function before calling xb_startio().
o Fix a couple of KASSERT()s.
o Fix a check in the xb_remove_* macro to be a little more specific.
sys/xen/gnttab.h:
sys/xen/gnttab.c:
Define GNTTAB_LIST_END publicly as GRANT_REF_INVALID.
sys/dev/xen/netfront/netfront.c:
Use GRANT_REF_INVALID instead of driver private definitions of the
same constant.
sys/xen/gnttab.h:
sys/xen/gnttab.c:
Add the gnttab_end_foreign_access_references() API.
This API allows a client to batch the release of an array of grant
references, instead of coding a private for loop. The implementation
takes advantage of this batching to reduce lock overhead to one
acquisition and release per-batch instead of per-freed grant reference.
While here, reduce the duration the gnttab_list_lock is held during
gnttab_free_grant_references() operations. The search to find the
tail of the incoming free list does not rely on global state and so
can be performed without holding the lock.
sys/dev/xen/xenpci/evtchn.c:
sys/dev/xen/evtchn/evtchn.c:
sys/xen/xen_intr.h:
o Implement the bind_interdomain_evtchn_to_irqhandler API for HVM mode.
This allows an HVM domain to serve back end devices to other domains.
This API is already implemented for PV mode.
o Synchronize the API between HVM and PV.
sys/dev/xen/xenpci/xenpci.c:
o Scan the full region of CPUID space in which the Xen VMM interface
may be implemented. On systems using SuSE as a Dom0 where the
Viridian API is also exported, the VMM interface is above the region
we used to search.
o Pass through bus_alloc_resource() calls so that XenBus drivers
attaching on an HVM system can allocate unused physical address
space from the nexus. The block back driver makes use of this
facility.
sys/i386/xen/xen_machdep.c:
Use the correct type for accessing the statically mapped xenstore
metadata.
sys/xen/interface/hvm/params.h:
sys/xen/xenstore/xenstore.c:
Move hvm_get_parameter() to the correct global header file instead
of as a private method to the XenStore.
sys/xen/interface/io/protocols.h:
Sync with vendor.
sys/xeninterface/io/ring.h:
Add macro for calculating the number of ring pages needed for an N
deep ring.
To avoid duplication within the macros, create and use the new
__RING_HEADER_SIZE() macro. This macro calculates the size of the
ring book keeping struct (producer/consumer indexes, etc.) that
resides at the head of the ring.
Add the __RING_PAGES() macro which calculates the number of shared
ring pages required to support a ring with the given number of
requests.
These APIs are used to support the multi-page ring version of the
Xen block API.
sys/xeninterface/io/xenbus.h:
Add Comments.
sys/xen/xenbus/...
o Refactor the FreeBSD XenBus support code to allow for both front and
backend device attachments.
o Make use of new config_intr_hook capabilities to allow front and back
devices to be probed/attached in parallel.
o Fix bugs in probe/attach state machine that could cause the system to
hang when confronted with a failure either in the local domain or in
a remote domain to which one of our driver instances is attaching.
o Publish all required state to the XenStore on device detach and
failure. The majority of the missing functionality was for serving
as a back end since the typical "hot-plug" scripts in Dom0 don't
handle the case of cleaning up for a "service domain" that is not
itself.
o Add dynamic sysctl nodes exposing the generic ivars of
XenBus devices.
o Add doxygen style comments to the majority of the code.
o Cleanup types, formatting, etc.
sys/xen/xenbus/xenbusb.c:
Common code used by both front and back XenBus busses.
sys/xen/xenbus/xenbusb_if.m:
Method definitions for a XenBus bus.
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusb_back.c:
XenBus bus specialization for front and back devices.
MFC after: 1 month
279 lines
9.4 KiB
C
279 lines
9.4 KiB
C
/******************************************************************************
|
|
* Copyright (C) 2005 Rusty Russell, IBM Corporation
|
|
* Copyright (C) 2005 XenSource Ltd.
|
|
*
|
|
* This file may be distributed separately from the Linux kernel, or
|
|
* incorporated into other software packages, subject to the following license:
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this source file (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.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/**
|
|
* \file xenbusvar.h
|
|
*
|
|
* \brief Datastructures and function declarations for usedby device
|
|
* drivers operating on the XenBus.
|
|
*/
|
|
|
|
#ifndef _XEN_XENBUS_XENBUSVAR_H
|
|
#define _XEN_XENBUS_XENBUSVAR_H
|
|
|
|
#include <sys/queue.h>
|
|
#include <sys/bus.h>
|
|
#include <sys/eventhandler.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/sbuf.h>
|
|
|
|
#include <machine/stdarg.h>
|
|
#include <machine/xen/xen-os.h>
|
|
|
|
#include <xen/interface/grant_table.h>
|
|
#include <xen/interface/io/xenbus.h>
|
|
#include <xen/interface/io/xs_wire.h>
|
|
|
|
#include <xen/xenstore/xenstorevar.h>
|
|
|
|
#include "xenbus_if.h"
|
|
|
|
/* XenBus allocations including XenStore data returned to clients. */
|
|
MALLOC_DECLARE(M_XENBUS);
|
|
|
|
enum {
|
|
/**
|
|
* Path of this device node.
|
|
*/
|
|
XENBUS_IVAR_NODE,
|
|
|
|
/**
|
|
* The device type (e.g. vif, vbd).
|
|
*/
|
|
XENBUS_IVAR_TYPE,
|
|
|
|
/**
|
|
* The state of this device (not the otherend's state).
|
|
*/
|
|
XENBUS_IVAR_STATE,
|
|
|
|
/**
|
|
* Domain ID of the other end device.
|
|
*/
|
|
XENBUS_IVAR_OTHEREND_ID,
|
|
|
|
/**
|
|
* Path of the other end device.
|
|
*/
|
|
XENBUS_IVAR_OTHEREND_PATH
|
|
};
|
|
|
|
/**
|
|
* Simplified accessors for xenbus devices
|
|
*/
|
|
#define XENBUS_ACCESSOR(var, ivar, type) \
|
|
__BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type)
|
|
|
|
XENBUS_ACCESSOR(node, NODE, const char *)
|
|
XENBUS_ACCESSOR(type, TYPE, const char *)
|
|
XENBUS_ACCESSOR(state, STATE, enum xenbus_state)
|
|
XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int)
|
|
XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *)
|
|
|
|
/**
|
|
* Return the state of a XenBus device.
|
|
*
|
|
* \param path The root XenStore path for the device.
|
|
*
|
|
* \return The current state of the device or XenbusStateClosed if no
|
|
* state can be read.
|
|
*/
|
|
XenbusState xenbus_read_driver_state(const char *path);
|
|
|
|
/**
|
|
* Initialize and register a watch on the given path (client suplied storage).
|
|
*
|
|
* \param dev The XenBus device requesting the watch service.
|
|
* \param path The XenStore path of the object to be watched. The
|
|
* storage for this string must be stable for the lifetime
|
|
* of the watch.
|
|
* \param watch The watch object to use for this request. This object
|
|
* must be stable for the lifetime of the watch.
|
|
* \param callback The function to call when XenStore objects at or below
|
|
* path are modified.
|
|
*
|
|
* \return On success, 0. Otherwise an errno value indicating the
|
|
* type of failure.
|
|
*
|
|
* \note On error, the device 'dev' will be switched to the XenbusStateClosing
|
|
* state and the returned error is saved in the per-device error node
|
|
* for dev in the XenStore.
|
|
*/
|
|
int xenbus_watch_path(device_t dev, char *path,
|
|
struct xs_watch *watch,
|
|
xs_watch_cb_t *callback);
|
|
|
|
/**
|
|
* Initialize and register a watch at path/path2 in the XenStore.
|
|
*
|
|
* \param dev The XenBus device requesting the watch service.
|
|
* \param path The base XenStore path of the object to be watched.
|
|
* \param path2 The tail XenStore path of the object to be watched.
|
|
* \param watch The watch object to use for this request. This object
|
|
* must be stable for the lifetime of the watch.
|
|
* \param callback The function to call when XenStore objects at or below
|
|
* path are modified.
|
|
*
|
|
* \return On success, 0. Otherwise an errno value indicating the
|
|
* type of failure.
|
|
*
|
|
* \note On error, \a dev will be switched to the XenbusStateClosing
|
|
* state and the returned error is saved in the per-device error node
|
|
* for \a dev in the XenStore.
|
|
*
|
|
* Similar to xenbus_watch_path, however the storage for the path to the
|
|
* watched object is allocated from the heap and filled with "path '/' path2".
|
|
* Should a call to this function succeed, it is the callers responsibility
|
|
* to free watch->node using the M_XENBUS malloc type.
|
|
*/
|
|
int xenbus_watch_path2(device_t dev, const char *path,
|
|
const char *path2, struct xs_watch *watch,
|
|
xs_watch_cb_t *callback);
|
|
|
|
/**
|
|
* Grant access to the given ring_mfn to the peer of the given device.
|
|
*
|
|
* \param dev The device granting access to the ring page.
|
|
* \param ring_mfn The guest machine page number of the page to grant
|
|
* peer access rights.
|
|
* \param refp[out] The grant reference for the page.
|
|
*
|
|
* \return On success, 0. Otherwise an errno value indicating the
|
|
* type of failure.
|
|
*
|
|
* A successful call to xenbus_grant_ring should be paired with a call
|
|
* to gnttab_end_foreign_access() when foregn access to this page is no
|
|
* longer requried.
|
|
*
|
|
* \note On error, \a dev will be switched to the XenbusStateClosing
|
|
* state and the returned error is saved in the per-device error node
|
|
* for \a dev in the XenStore.
|
|
*/
|
|
int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
|
|
|
|
/**
|
|
* Allocate an event channel for the given XenBus device.
|
|
*
|
|
* \param dev The device for which to allocate the event channel.
|
|
* \param port[out] The port identifier for the allocated event channel.
|
|
*
|
|
* \return On success, 0. Otherwise an errno value indicating the
|
|
* type of failure.
|
|
*
|
|
* A successfully allocated event channel should be free'd using
|
|
* xenbus_free_evtchn().
|
|
*
|
|
* \note On error, \a dev will be switched to the XenbusStateClosing
|
|
* state and the returned error is saved in the per-device error node
|
|
* for \a dev in the XenStore.
|
|
*/
|
|
int xenbus_alloc_evtchn(device_t dev, evtchn_port_t *port);
|
|
|
|
/**
|
|
* Free an existing event channel.
|
|
*
|
|
* \param dev The device which allocated this event channel.
|
|
* \param port The port identifier for the event channel to free.
|
|
*
|
|
* \return On success, 0. Otherwise an errno value indicating the
|
|
* type of failure.
|
|
*
|
|
* \note On error, \a dev will be switched to the XenbusStateClosing
|
|
* state and the returned error is saved in the per-device error node
|
|
* for \a dev in the XenStore.
|
|
*/
|
|
int xenbus_free_evtchn(device_t dev, evtchn_port_t port);
|
|
|
|
/**
|
|
* Record the given errno, along with the given, printf-style, formatted
|
|
* message in dev's device specific error node in the XenStore.
|
|
*
|
|
* \param dev The device which encountered the error.
|
|
* \param err The errno value corresponding to the error.
|
|
* \param fmt Printf format string followed by a variable number of
|
|
* printf arguments.
|
|
*/
|
|
void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
|
|
__attribute__((format(printf, 3, 4)));
|
|
|
|
/**
|
|
* va_list version of xenbus_dev_error().
|
|
*
|
|
* \param dev The device which encountered the error.
|
|
* \param err The errno value corresponding to the error.
|
|
* \param fmt Printf format string.
|
|
* \param ap Va_list of printf arguments.
|
|
*/
|
|
void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
|
|
__attribute__((format(printf, 3, 0)));
|
|
|
|
/**
|
|
* Equivalent to xenbus_dev_error(), followed by
|
|
* xenbus_set_state(dev, XenbusStateClosing).
|
|
*
|
|
* \param dev The device which encountered the error.
|
|
* \param err The errno value corresponding to the error.
|
|
* \param fmt Printf format string followed by a variable number of
|
|
* printf arguments.
|
|
*/
|
|
void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
|
|
__attribute__((format(printf, 3, 4)));
|
|
|
|
/**
|
|
* va_list version of xenbus_dev_fatal().
|
|
*
|
|
* \param dev The device which encountered the error.
|
|
* \param err The errno value corresponding to the error.
|
|
* \param fmt Printf format string.
|
|
* \param ap Va_list of printf arguments.
|
|
*/
|
|
void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
|
|
__attribute__((format(printf, 3, 0)));
|
|
|
|
/**
|
|
* Convert a member of the xenbus_state enum into an ASCII string.
|
|
*
|
|
* /param state The XenBus state to lookup.
|
|
*
|
|
* /return A string representing state or, for unrecognized states,
|
|
* the string "Unknown".
|
|
*/
|
|
const char *xenbus_strstate(enum xenbus_state state);
|
|
|
|
/**
|
|
* Return the value of a XenBus device's "online" node within the XenStore.
|
|
*
|
|
* \param dev The XenBus device to query.
|
|
*
|
|
* \return The value of the "online" node for the device. If the node
|
|
* does not exist, 0 (offline) is returned.
|
|
*/
|
|
int xenbus_dev_is_online(device_t dev);
|
|
|
|
#endif /* _XEN_XENBUS_XENBUSVAR_H */
|