freebsd-dev/sys/xen/xenbus/xenbus.c
Justin T. Gibbs 76acc41fb7 Implement vector callback for PVHVM and unify event channel implementations
Re-structure Xen HVM support so that:
	- Xen is detected and hypercalls can be performed very
	  early in system startup.
	- Xen interrupt services are implemented using FreeBSD's native
	  interrupt delivery infrastructure.
	- the Xen interrupt service implementation is shared between PV
	  and HVM guests.
	- Xen interrupt handlers can optionally use a filter handler
	  in order to avoid the overhead of dispatch to an interrupt
	  thread.
	- interrupt load can be distributed among all available CPUs.
	- the overhead of accessing the emulated local and I/O apics
	  on HVM is removed for event channel port events.
	- a similar optimization can eventually, and fairly easily,
	  be used to optimize MSI.

Early Xen detection, HVM refactoring, PVHVM interrupt infrastructure,
and misc Xen cleanups:

Sponsored by: Spectra Logic Corporation

Unification of PV & HVM interrupt infrastructure, bug fixes,
and misc Xen cleanups:

Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D

sys/x86/x86/local_apic.c:
sys/amd64/include/apicvar.h:
sys/i386/include/apicvar.h:
sys/amd64/amd64/apic_vector.S:
sys/i386/i386/apic_vector.s:
sys/amd64/amd64/machdep.c:
sys/i386/i386/machdep.c:
sys/i386/xen/exception.s:
sys/x86/include/segments.h:
	Reserve IDT vector 0x93 for the Xen event channel upcall
	interrupt handler.  On Hypervisors that support the direct
	vector callback feature, we can request that this vector be
	called directly by an injected HVM interrupt event, instead
	of a simulated PCI interrupt on the Xen platform PCI device.
	This avoids all of the overhead of dealing with the emulated
	I/O APIC and local APIC.  It also means that the Hypervisor
	can inject these events on any CPU, allowing upcalls for
	different ports to be handled in parallel.

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
	Map Xen per-vcpu area during AP startup.

sys/amd64/include/intr_machdep.h:
sys/i386/include/intr_machdep.h:
	Increase the FreeBSD IRQ vector table to include space
	for event channel interrupt sources.

sys/amd64/include/pcpu.h:
sys/i386/include/pcpu.h:
	Remove Xen HVM per-cpu variable data.  These fields are now
	allocated via the dynamic per-cpu scheme.  See xen_intr.c
	for details.

sys/amd64/include/xen/hypercall.h:
sys/dev/xen/blkback/blkback.c:
sys/i386/include/xen/xenvar.h:
sys/i386/xen/clock.c:
sys/i386/xen/xen_machdep.c:
sys/xen/gnttab.c:
	Prefer FreeBSD primatives to Linux ones in Xen support code.

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
sys/xen/xen-os.h:
sys/dev/xen/balloon/balloon.c:
sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/console/xencons_ring.c:
sys/dev/xen/control/control.c:
sys/dev/xen/netback/netback.c:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/xenpci/xenpci.c:
sys/i386/i386/machdep.c:
sys/i386/include/pmap.h:
sys/i386/include/xen/xenfunc.h:
sys/i386/isa/npx.c:
sys/i386/xen/clock.c:
sys/i386/xen/mp_machdep.c:
sys/i386/xen/mptable.c:
sys/i386/xen/xen_clock_util.c:
sys/i386/xen/xen_machdep.c:
sys/i386/xen/xen_rtc.c:
sys/xen/evtchn/evtchn_dev.c:
sys/xen/features.c:
sys/xen/gnttab.c:
sys/xen/gnttab.h:
sys/xen/hvm.h:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_if.m:
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenstore/xenstore.c:
sys/xen/xenstore/xenstore_dev.c:
sys/xen/xenstore/xenstorevar.h:
	Pull common Xen OS support functions/settings into xen/xen-os.h.

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
sys/xen/xen-os.h:
	Remove constants, macros, and functions unused in FreeBSD's Xen
	support.

sys/xen/xen-os.h:
sys/i386/xen/xen_machdep.c:
sys/x86/xen/hvm.c:
	Introduce new functions xen_domain(), xen_pv_domain(), and
	xen_hvm_domain().  These are used in favor of #ifdefs so that
	FreeBSD can dynamically detect and adapt to the presence of
	a hypervisor.  The goal is to have an HVM optimized GENERIC,
	but more is necessary before this is possible.

sys/amd64/amd64/machdep.c:
sys/dev/xen/xenpci/xenpcivar.h:
sys/dev/xen/xenpci/xenpci.c:
sys/x86/xen/hvm.c:
sys/sys/kernel.h:
	Refactor magic ioport, Hypercall table and Hypervisor shared
	information page setup, and move it to a dedicated HVM support
	module.

	HVM mode initialization is now triggered during the
	SI_SUB_HYPERVISOR phase of system startup.  This currently
	occurs just after the kernel VM is fully setup which is
	just enough infrastructure to allow the hypercall table
	and shared info page to be properly mapped.

sys/xen/hvm.h:
sys/x86/xen/hvm.c:
	Add definitions and a method for configuring Hypervisor event
	delievery via a direct vector callback.

sys/amd64/include/xen/xen-os.h:
sys/x86/xen/hvm.c:

sys/conf/files:
sys/conf/files.amd64:
sys/conf/files.i386:
	Adjust kernel build to reflect the refactoring of early
	Xen startup code and Xen interrupt services.

sys/dev/xen/blkback/blkback.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkfront/block.h:
sys/dev/xen/control/control.c:
sys/dev/xen/evtchn/evtchn_dev.c:
sys/dev/xen/netback/netback.c:
sys/dev/xen/netfront/netfront.c:
sys/xen/xenstore/xenstore.c:
sys/xen/evtchn/evtchn_dev.c:
sys/dev/xen/console/console.c:
sys/dev/xen/console/xencons_ring.c
	Adjust drivers to use new xen_intr_*() API.

sys/dev/xen/blkback/blkback.c:
	Since blkback defers all event handling to a taskqueue,
	convert this task queue to a "fast" taskqueue, and schedule
	it via an interrupt filter.  This avoids an unnecessary
	ithread context switch.

sys/xen/xenstore/xenstore.c:
	The xenstore driver is MPSAFE.  Indicate as much when
	registering its interrupt handler.

sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbusvar.h:
	Remove unused event channel APIs.

sys/xen/evtchn.h:
	Remove all kernel Xen interrupt service API definitions
	from this file.  It is now only used for structure and
	ioctl definitions related to the event channel userland
	device driver.

	Update the definitions in this file to match those from
	NetBSD.  Implementing this interface will be necessary for
	Dom0 support.

sys/xen/evtchn/evtchnvar.h:
	Add a header file for implemenation internal APIs related
	to managing event channels event delivery.  This is used
	to allow, for example, the event channel userland device
	driver to access low-level routines that typical kernel
	consumers of event channel services should never access.

sys/xen/interface/event_channel.h:
sys/xen/xen_intr.h:
	Standardize on the evtchn_port_t type for referring to
	an event channel port id.  In order to prevent low-level
	event channel APIs from leaking to kernel consumers who
	should not have access to this data, the type is defined
	twice: Once in the Xen provided event_channel.h, and again
	in xen/xen_intr.h.  The double declaration is protected by
	__XEN_EVTCHN_PORT_DEFINED__ to ensure it is never declared
	twice within a given compilation unit.

sys/xen/xen_intr.h:
sys/xen/evtchn/evtchn.c:
sys/x86/xen/xen_intr.c:
sys/dev/xen/xenpci/evtchn.c:
sys/dev/xen/xenpci/xenpcivar.h:
	New implementation of Xen interrupt services.  This is
	similar in many respects to the i386 PV implementation with
	the exception that events for bound to event channel ports
	(i.e. not IPI, virtual IRQ, or physical IRQ) are further
	optimized to avoid mask/unmask operations that aren't
	necessary for these edge triggered events.

	Stubs exist for supporting physical IRQ binding, but will
	need additional work before this implementation can be
	fully shared between PV and HVM.

sys/amd64/amd64/mp_machdep.c:
sys/i386/i386/mp_machdep.c:
sys/i386/xen/mp_machdep.c
sys/x86/xen/hvm.c:
	Add support for placing vcpu_info into an arbritary memory
	page instead of using HYPERVISOR_shared_info->vcpu_info.
	This allows the creation of domains with more than 32 vcpus.

sys/i386/i386/machdep.c:
sys/i386/xen/clock.c:
sys/i386/xen/xen_machdep.c:
sys/i386/xen/exception.s:
	Add support for new event channle implementation.
2013-08-29 19:52:18 +00:00

260 lines
6.6 KiB
C

/******************************************************************************
* 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.
*/
/**
* \file xenbus.c
*
* \brief Client-facing interface for the Xenbus driver.
*
* In other words, the interface between the Xenbus and the device-specific
* code, be it the frontend or the backend of that driver.
*/
#if 0
#define DPRINTK(fmt, args...) \
printk("xenbus_client (%s:%d) " fmt ".\n", __FUNCTION__, __LINE__, ##args)
#else
#define DPRINTK(fmt, args...) ((void)0)
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/libkern.h>
#include <sys/sbuf.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/evtchn.h>
#include <xen/gnttab.h>
#include <xen/xenbus/xenbusvar.h>
#include <machine/stdarg.h>
MALLOC_DEFINE(M_XENBUS, "xenbus", "XenBus Support");
/*------------------------- Private Functions --------------------------------*/
/**
* \brief Construct the error path corresponding to the given XenBus
* device.
*
* \param dev The XenBus device for which we are constructing an error path.
*
* \return On success, the contructed error path. Otherwise NULL.
*
* It is the caller's responsibility to free any returned error path
* node using the M_XENBUS malloc type.
*/
static char *
error_path(device_t dev)
{
char *path_buffer = malloc(strlen("error/")
+ strlen(xenbus_get_node(dev)) + 1,M_XENBUS, M_WAITOK);
strcpy(path_buffer, "error/");
strcpy(path_buffer + strlen("error/"), xenbus_get_node(dev));
return (path_buffer);
}
/*--------------------------- Public Functions -------------------------------*/
/*-------- API comments for these methods can be found in xenbusvar.h --------*/
const char *
xenbus_strstate(XenbusState state)
{
static const char *const name[] = {
[ XenbusStateUnknown ] = "Unknown",
[ XenbusStateInitialising ] = "Initialising",
[ XenbusStateInitWait ] = "InitWait",
[ XenbusStateInitialised ] = "Initialised",
[ XenbusStateConnected ] = "Connected",
[ XenbusStateClosing ] = "Closing",
[ XenbusStateClosed ] = "Closed",
};
return ((state < (XenbusStateClosed + 1)) ? name[state] : "INVALID");
}
int
xenbus_watch_path(device_t dev, char *path, struct xs_watch *watch,
xs_watch_cb_t *callback, uintptr_t callback_data)
{
int error;
watch->node = path;
watch->callback = callback;
watch->callback_data = callback_data;
error = xs_register_watch(watch);
if (error) {
watch->node = NULL;
watch->callback = NULL;
xenbus_dev_fatal(dev, error, "adding watch on %s", path);
}
return (error);
}
int
xenbus_watch_path2(device_t dev, const char *path,
const char *path2, struct xs_watch *watch,
xs_watch_cb_t *callback, uintptr_t callback_data)
{
int error;
char *state = malloc(strlen(path) + 1 + strlen(path2) + 1,
M_XENBUS, M_WAITOK);
strcpy(state, path);
strcat(state, "/");
strcat(state, path2);
error = xenbus_watch_path(dev, state, watch, callback, callback_data);
if (error) {
free(state,M_XENBUS);
}
return (error);
}
void
xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
{
int ret;
unsigned int len;
char *printf_buffer = NULL, *path_buffer = NULL;
#define PRINTF_BUFFER_SIZE 4096
printf_buffer = malloc(PRINTF_BUFFER_SIZE,M_XENBUS, M_WAITOK);
len = sprintf(printf_buffer, "%i ", err);
ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap);
KASSERT(len + ret <= PRINTF_BUFFER_SIZE-1, ("xenbus error message too big"));
device_printf(dev, "Error %s\n", printf_buffer);
path_buffer = error_path(dev);
if (path_buffer == NULL) {
printf("xenbus: failed to write error node for %s (%s)\n",
xenbus_get_node(dev), printf_buffer);
goto fail;
}
if (xs_write(XST_NIL, path_buffer, "error", printf_buffer) != 0) {
printf("xenbus: failed to write error node for %s (%s)\n",
xenbus_get_node(dev), printf_buffer);
goto fail;
}
fail:
if (printf_buffer)
free(printf_buffer,M_XENBUS);
if (path_buffer)
free(path_buffer,M_XENBUS);
}
void
xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
xenbus_dev_verror(dev, err, fmt, ap);
va_end(ap);
}
void
xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list ap)
{
xenbus_dev_verror(dev, err, fmt, ap);
device_printf(dev, "Fatal error. Transitioning to Closing State\n");
xenbus_set_state(dev, XenbusStateClosing);
}
void
xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
xenbus_dev_vfatal(dev, err, fmt, ap);
va_end(ap);
}
int
xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp)
{
int error;
error = gnttab_grant_foreign_access(
xenbus_get_otherend_id(dev), ring_mfn, 0, refp);
if (error) {
xenbus_dev_fatal(dev, error, "granting access to ring page");
return (error);
}
return (0);
}
XenbusState
xenbus_read_driver_state(const char *path)
{
XenbusState result;
int error;
error = xs_gather(XST_NIL, path, "state", "%d", &result, NULL);
if (error)
result = XenbusStateClosed;
return (result);
}
int
xenbus_dev_is_online(device_t dev)
{
const char *path;
int error;
int value;
path = xenbus_get_node(dev);
error = xs_gather(XST_NIL, path, "online", "%d", &value, NULL);
if (error != 0) {
/* Default to not online. */
value = 0;
}
return (value);
}
void
xenbus_localend_changed(device_t dev, const char *path)
{
}