Commit Graph

19 Commits

Author SHA1 Message Date
royger
919b7d8b7c xen: implement the privcmd user-space device
This device is only attached to priviledged domains, and allows the
toolstack to interact with Xen. The two functions of the privcmd
interface is to allow the execution of hypercalls from user-space, and
the mapping of foreign domain memory.

Sponsored by: Citrix Systems R&D

i386/include/xen/hypercall.h:
amd64/include/xen/hypercall.h:
 - Introduce a function to make generic hypercalls into Xen.

xen/interface/xen.h:
xen/interface/memory.h:
 - Import the new hypercall XENMEM_add_to_physmap_range used by
   auto-translated guests to map memory from foreign domains.

dev/xen/privcmd/privcmd.c:
 - This device has the following functions:
   - Allow user-space applications to make hypercalls into Xen.
   - Allow user-space applications to map memory from foreign domains,
     this is accomplished using the newly introduced hypercall
     (XENMEM_add_to_physmap_range).

xen/privcmd.h:
 - Public ioctl interface for the privcmd device.

x86/xen/hvm.c:
 - Remove declaration of hypercall_page, now it's declared in
   hypercall.h.

conf/files:
 - Add the privcmd device to the build process.
2014-10-22 17:07:20 +00:00
royger
c5a5f5947f msi: add Xen MSI implementation
This patch adds support for MSI interrupts when running on Xen. Apart
from adding the Xen related code needed in order to register MSI
interrupts this patch also makes the msi_init function a hook in
init_ops, so different MSI implementations can have different
initialization functions.

Sponsored by: Citrix Systems R&D

xen/interface/physdev.h:
 - Add the MAP_PIRQ_TYPE_MULTI_MSI to map multi-vector MSI to the Xen
   public interface.

x86/include/init.h:
 - Add a hook for setting custom msi_init methods.

amd64/amd64/machdep.c:
i386/i386/machdep.c:
 - Set the default msi_init hook to point to the native MSI
   initialization method.

x86/xen/pv.c:
 - Set the Xen MSI init hook when running as a Xen guest.

x86/x86/local_apic.c:
 - Call the msi_init hook instead of directly calling msi_init.

xen/xen_intr.h:
x86/xen/xen_intr.c:
 - Introduce support for registering/releasing MSI interrupts with
   Xen.
 - The MSI interrupts will use the same PIC as the IO APIC interrupts.

xen/xen_msi.h:
x86/xen/xen_msi.c:
 - Introduce a Xen MSI implementation.

x86/xen/xen_nexus.c:
 - Overwrite the default MSI hooks in the Xen Nexus to use the Xen MSI
   implementation.

x86/xen/xen_pci.c:
 - Introduce a Xen specific PCI bus that inherits from the ACPI PCI
   bus and overwrites the native MSI methods.
 - This is needed because when running under Xen the MSI messages used
   to configure MSI interrupts on PCI devices are written by Xen
   itself.

dev/acpica/acpi_pci.c:
 - Lower the quality of the ACPI PCI bus so the newly introduced Xen
   PCI bus can take over when needed.

conf/files.i386:
conf/files.amd64:
 - Add the newly created files to the build process.
2014-09-30 16:46:45 +00:00
marcel
9f28abd980 Remove ia64.
This includes:
o   All directories named *ia64*
o   All files named *ia64*
o   All ia64-specific code guarded by __ia64__
o   All ia64-specific makefile logic
o   Mention of ia64 in comments and documentation

This excludes:
o   Everything under contrib/
o   Everything under crypto/
o   sys/xen/interface
o   sys/sys/elf_common.h

Discussed at: BSDcan
2014-07-07 00:27:09 +00:00
gibbs
fcdbf70fd9 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
gibbs
16fc3a3c4b Adjust i386 Xen PV support for updated Xen interface files.
sys/i386/include/xen/xenvar.h:
sys/i386/xen/xen_machdep.c:
sys/xen/interface/foreign/structs.py:
sys/xen/evtchn/evtchn.c:
	MAX_VIRT_CPUS => XEN_LEGACY_MAX_VCPUS

Submitted by:	Roger Pau Monné
Reviewed by:	gibbs
2013-06-17 01:43:07 +00:00
gibbs
d4000dfe1d Upgrade Xen interface headers to Xen 4.2.1.
Move FreeBSD from interface version 0x00030204 to 0x00030208.
Updates are required to our grant table implementation before we
can bump this further.

sys/xen/hvm.h:
	Replace the implementation of hvm_get_parameter(), formerly located
	in sys/xen/interface/hvm/params.h.  Linux has a similar file which
	primarily stores this function.

sys/xen/xenstore/xenstore.c:
	Include new xen/hvm.h header file to get hvm_get_parameter().

sys/amd64/include/xen/xen-os.h:
sys/i386/include/xen/xen-os.h:
	Correctly protect function definition and variables from being
	included into assembly files in xen-os.h

	Xen memory barriers are now prefixed with "xen_" to avoid conflicts
	with OS native primatives.  Define Xen memory barriers in terms of
	the native FreeBSD primatives.

Sponsored by:	Spectra Logic Corporation
Reviewed by:	Roger Pau Monné
Tested by:	Roger Pau Monné
Obtained from:	Roger Pau Monné (bug fixes)
2013-06-14 23:43:44 +00:00
eadler
aaedfc3e7e Make xen python scripts work with python3
Approved by:	cperciva
MFC after:	3 days
2012-10-22 02:29:53 +00:00
gibbs
bf47057ad9 blkif interface comment cleanups. No functional changes
sys/xen/interface/io/blkif.h:
 o Insert space in "Red Hat".
 o Fix typo "discard-aligment" -> "discard-alignment"
 o Fix typo "unamp" -> "unmap"
 o Fix typo "formated" -> "formatted"
 o Clarify the text for "params".
 o Clarify the text for "sector-size".
 o Clarify the text for "max-requests" in the backend section.
2012-02-29 17:47:01 +00:00
gibbs
d67f43fbfd Fix "_" vs. "-" typo in a comment. No functional changes. 2012-02-16 21:47:17 +00:00
gibbs
62950d5517 Enhance documentation, improve interoperability, and fix defects in
FreeBSD's front and back Xen blkif interface drivers.

sys/dev/xen/blkfront/block.h:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkback/blkback.c:
	Replace FreeBSD specific multi-page ring impelementation with
	support for both the Citrix and Amazon/RedHat versions of this
	extension.

sys/dev/xen/blkfront/blkfront.c:
	o Add a per-instance sysctl tree that exposes all negotiated
	  transport parameters (ring pages, max number of requests,
	  max request size, max number of segments).
	o In blkfront_vdevice_to_unit() add a missing return statement
	  so that we properly identify the unit number for high numbered
	  xvd devices.

sys/dev/xen/blkback/blkback.c:
	o Add static dtrace probes for several events in this driver.
	o Defer connection shutdown processing until the front-end
	  enters the closed state.  This avoids prematurely tearing
	  down the connection when buggy front-ends transition to the
	  closing state, even though the device is open and they
	  veto the close request from the tool stack.
	o Add nodes for maximum request size and the number of active
	  ring pages to the exising, per-instance, sysctl tree.
	o Miscelaneous style cleanup.

sys/xen/interface/io/blkif.h:
	o Add extensive documentation of the XenStore nodes used to
	  implement the blkif interface.
	o Document the startup sequence between a front and back driver.
	o Add structures and documenatation for the "discard" feature
	  (AKA Trim).
	o Cleanup some definitions related to FreeBSD's request
	  number/size/segment-limit extension.

sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkback/blkback.c:
sys/xen/xenbus/xenbusvar.h:
	Add the convenience function xenbus_get_otherend_state() and
	use it to simplify some logic in both block-front and block-back.

MFC after:	1 day
2012-02-15 06:45:49 +00:00
ken
7e235aa8ee Add the GSO prefix descriptor define.
MFC after:	3 days
2012-02-01 20:19:33 +00:00
ken
7f685c218a Xen netback driver rewrite.
share/man/man4/Makefile,
share/man/man4/xnb.4,
sys/dev/xen/netback/netback.c,
sys/dev/xen/netback/netback_unit_tests.c:

	Rewrote the netback driver for xen to attach properly via newbus
	and work properly in both HVM and PVM mode (only HVM is tested).
	Works with the in-tree FreeBSD netfront driver or the Windows
	netfront driver from SuSE.  Has not been extensively tested with
	a Linux netfront driver.  Does not implement LRO, TSO, or
	polling.  Includes unit tests that may be run through sysctl
	after compiling with XNB_DEBUG defined.

sys/dev/xen/blkback/blkback.c,
sys/xen/interface/io/netif.h:

	Comment elaboration.

sys/kern/uipc_mbuf.c:

	Fix page fault in kernel mode when calling m_print() on a
	null mbuf.  Since m_print() is only used for debugging, there
	are no performance concerns for extra error checking code.

sys/kern/subr_scanf.c:

	Add the "hh" and "ll" width specifiers from C99 to scanf().
	A few callers were already using "ll" even though scanf()
	was handling it as "l".

Submitted by:	Alan Somers <alans@spectralogic.com>
Submitted by:	John Suykerbuyk <johns@spectralogic.com>
Sponsored by:	Spectra Logic
MFC after:	1 week
Reviewed by:	ken
2012-01-26 16:35:09 +00:00
gibbs
c8e3d11e24 Monitor and emit events for XenStore changes to XenBus trees
of the devices we manage.  These changes can be due to writes
we make ourselves or due to changes made by the control domain.
The goal of these changes is to insure that all state transitions
can be detected regardless of their source and to allow common
device policies (e.g. "onlined" backend devices) to be centralized
in the XenBus bus code.

sys/xen/xenbus/xenbusvar.h:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbus_if.m:
	Add a new method for XenBus drivers "localend_changed".
	This method is invoked whenever a write is detected to
	a device's XenBus tree.  The default implementation of
	this method is a no-op.

sys/xen/xenbus/xenbus_if.m:
sys/dev/xen/netfront/netfront.c:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkback/blkback.c:
	Change the signature of the "otherend_changed" method.
	This notification cannot fail, so it should return void.

sys/xen/xenbus/xenbusb_back.c:
	Add "online" device handling to the XenBus Back Bus
	support code.  An online backend device remains active
	after a front-end detaches as a reconnect is expected
	to occur in the near future.

sys/xen/interface/io/xenbus.h:
	Add comment block further explaining the meaning and
	driver responsibilities associated with the XenBus
	Closed state.

sys/xen/xenbus/xenbusb.c:
sys/xen/xenbus/xenbusb.h:
sys/xen/xenbus/xenbusb_back.c:
sys/xen/xenbus/xenbusb_front.c:
sys/xen/xenbus/xenbusb_if.m:
	o Register a XenStore watch against the local XenBus tree
	  for all devices.
	o Cache the string length of the path to our local tree.
	o Allow the xenbus front and back drivers to hook/filter both
	  local and otherend watch processing.
	o Update the device ivar version of "state" when we detect
	  a XenStore update of that node.

sys/dev/xen/control/control.c:
sys/xen/xenbus/xenbus.c:
sys/xen/xenbus/xenbusb.c:
sys/xen/xenbus/xenbusb.h:
sys/xen/xenbus/xenbusvar.h:
sys/xen/xenstore/xenstorevar.h:
	Allow clients of the XenStore watch mechanism to attach
	a single uintptr_t worth of client data to the watch.
	This removes the need to carefully place client watch
	data within enclosing objects so that a cast or offsetof
	calculation can be used to convert from watch to enclosing
	object.

Sponsored by:	Spectra Logic Corporation
MFC after:	1 week
2011-06-11 04:59:01 +00:00
gibbs
831bbfaf75 Improve the Xen para-virtualized device infrastructure of FreeBSD:
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
2010-10-19 20:53:30 +00:00
dfr
598fb4217f Merge in support for Xen HVM on amd64 architecture. 2009-03-11 15:30:12 +00:00
dfr
19b6af98ec Clone Kip's Xen on stable/6 tree so that I can work on improving FreeBSD/amd64
performance in Xen's HVM mode.
2008-11-22 16:14:52 +00:00
kmacy
3d2b6bb54b Update xen/interface includes to the latest in mercurial
MFC after:	1 month
2008-09-26 05:29:39 +00:00
kmacy
ba5a88198a partial update to interface headers to 3.2
MFC after:	1 month
2008-09-25 07:01:31 +00:00
kmacy
0b389f773a Import OS interfaces to Xen services.
MFC after:	2 weeks
2008-08-12 07:36:56 +00:00