299090 |
04-May-2016 |
asomers |
Improve performance and functionality of the bitstring(3) api
Two new functions are provided, bit_ffs_at() and bit_ffc_at(), which allow for efficient searching of set or cleared bits starting from any bit offset within the bit string.
Performance is improved by operating on longs instead of bytes and using ffsl() for searches within a long. ffsl() is a compiler builtin in both clang and gcc for most architectures, converting what was a brute force while loop search into a couple of instructions.
All of the bitstring(3) API continues to be contained in the header file. Some of the functions are large enough that perhaps they should be uninlined and moved to a library, but that is beyond the scope of this commit.
sys/sys/bitstring.h: Convert the majority of the existing bit string implementation from macros to inline functions.
Properly protect the implementation from inadvertant macro expansion when included in a user's program by prefixing all private macros/functions and local variables with '_'.
Add bit_ffs_at() and bit_ffc_at(). Implement bit_ffs() and bit_ffc() in terms of their "at" counterparts.
Provide a kernel implementation of bit_alloc(), making the full API usable in the kernel.
Improve code documenation.
share/man/man3/bitstring.3: Add pre-exisiting API bit_ffc() to the synopsis.
Document new APIs.
Document the initialization state of the bit strings allocated/declared by bit_alloc() and bit_decl().
Correct documentation for bitstr_size(). The original code comments indicate the size is in bytes, not "elements of bitstr_t". The new implementation follows this lead. Only hastd assumed "elements" rather than bytes and it has been corrected.
etc/mtree/BSD.tests.dist: tests/sys/Makefile: tests/sys/sys/Makefile: tests/sys/sys/bitstring.c: Add tests for all existing and new functionality.
include/bitstring.h Include all headers needed by sys/bitstring.h
lib/libbluetooth/bluetooth.h: usr.sbin/bluetooth/hccontrol/le.c: Include bitstring.h instead of sys/bitstring.h.
sbin/hastd/activemap.c: Correct usage of bitstr_size().
sys/dev/xen/blkback/blkback.c Use new bit_alloc.
sys/kern/subr_unit.c: Remove hard-coded assumption that sizeof(bitstr_t) is 1. Get rid of unrb.busy, which caches the number of bits set in unrb.map. When INVARIANTS are disabled, nothing needs to know that information. callapse_unr can be adapted to use bit_ffs and bit_ffc instead. Eliminating unrb.busy saves memory, simplifies the code, and provides a slight speedup when INVARIANTS are disabled.
sys/net/flowtable.c: Use the new kernel implementation of bit-alloc, instead of hacking the old libc-dependent macro.
sys/sys/param.h Update __FreeBSD_version to indicate availability of new API
Submitted by: gibbs, asomers Reviewed by: gibbs, ngie MFC after: 4 weeks Sponsored by: Spectra Logic Corp Differential Revision: https://reviews.freebsd.org/D6004
|
289686 |
21-Oct-2015 |
royger |
xen: Code cleanup and small bug fixes
xen/hypervisor.h: - Remove unused helpers: MULTI_update_va_mapping, is_initial_xendomain, is_running_on_xen - Remove unused define CONFIG_X86_PAE - Remove unused variable xen_start_info: note that it's used inpcifront which is not built at all - Remove forward declaration of HYPERVISOR_crash
xen/xen-os.h: - Remove unused define CONFIG_X86_PAE - Drop unused helpers: test_and_clear_bit, clear_bit, force_evtchn_callback - Implement a generic version (based on ofed/include/linux/bitops.h) of set_bit and test_bit and prefix them by xen_ to avoid any use by other code than Xen. Note that It would be worth to investigate a generic implementation in FreeBSD. - Replace barrier() by __compiler_membar() - Replace cpu_relax() by cpu_spinwait(): it's exactly the same as rep;nop = pause
xen/xen_intr.h: - Move the prototype of xen_intr_handle_upcall in it: Use by all the platform
x86/xen/xen_intr.c: - Use BITSET* for the enabledbits: Avoid to use custom helpers - test_bit/set_bit has been renamed to xen_test_bit/xen_set_bit - Don't export the variable xen_intr_pcpu
dev/xen/blkback/blkback.c: - Fix the string format when XBB_DEBUG is enabled: host_addr is typed uint64_t
dev/xen/balloon/balloon.c: - Remove set but not used variable - Use the correct type for frame_list: xen_pfn_t represents the frame number on any architecture
dev/xen/control/control.c: - Return BUS_PROBE_WILDCARD in xs_probe: Returning 0 in a probe callback means the driver can handle this device. If by any chance xenstore is the first driver, every new device with the driver is unset will use xenstore.
dev/xen/grant-table/grant_table.c: - Remove unused cmpxchg - Drop unused include opt_pmap.h: Doesn't exist on ARM64 and it doesn't contain anything required for the code on x86
dev/xen/netfront/netfront.c: - Use the correct type for rx_pfn_array: xen_pfn_t represents the frame number on any architecture
dev/xen/netback/netback.c: - Use the correct type for gmfn: xen_pfn_t represents the frame number on any architecture
dev/xen/xenstore/xenstore.c: - Return BUS_PROBE_WILDCARD in xctrl_probe: Returning 0 in a probe callback means the driver can handle this device. If by any chance xenstore is the first driver, every new device with the driver is unset will use xenstore.
Note that with the changes, x86/include/xen/xen-os.h doesn't contain anymore arch-specific code. Although, a new series will add some helpers that differ between x86 and ARM64, so I've kept the headers for now.
Submitted by: Julien Grall <julien.grall@citrix.com> Reviewed by: royger Differential Revision: https://reviews.freebsd.org/D3921 Sponsored by: Citrix Systems R&D
|
272321 |
30-Sep-2014 |
royger |
xen: fix blkback pushing responses before releasing internal resources
Fix a problem where the blockback driver could run out of requests, despite the fact that we allocate enough request and reqlist structures to satisfy the maximum possible number of requests.
The problem was that we were sending responses back to the other end (blockfront) before freeing resources. The Citrix Windows driver is pretty agressive about queueing, and would queue more I/O to us immediately after we sent responses to it. We would run into a resource shortage and stall out I/O until we freed resources.
It isn't clear whether the request shortage condition was an indirect cause of the I/O hangs we've been seeing between Windows with the Citrix PV drivers and FreeBSD's blockback, but the above problem is certainly a bug.
Sponsored by: Spectra Logic Submitted by: ken Reviewed by: royger
dev/xen/blkback/blkback.c: - Break xbb_send_response() into two sub-functions, xbb_queue_response() and xbb_push_responses(). Remove xbb_send_response(), because it is no longer used.
- Adjust xbb_complete_reqlist() so that it calls the two new functions, and holds the mutex around both calls. The mutex insures that another context can't come along and push responses before we've freed our resources.
- Change xbb_release_reqlist() so that it requires the mutex to be held instead of acquiring the mutex itself. Both callers could easily hold the mutex while calling it, and one really needs to hold the mutex during the call.
- Add two new counters, accessible via sysctl variables. The first one counts the number of I/Os that are queued and waiting to be pushed (reqs_queued_for_completion). The second one (reqs_completed_with_error) counts the number of requests we've completed with an error status.
|
258541 |
25-Nov-2013 |
attilio |
- For kernel compiled only with KDTRACE_HOOKS and not any lock debugging option, unbreak the lock tracing release semantic by embedding calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined version of the releasing functions for mutex, rwlock and sxlock. Failing to do so skips the lockstat_probe_func invokation for unlocking. - As part of the LOCKSTAT support is inlined in mutex operation, for kernel compiled without lock debugging options, potentially every consumer must be compiled including opt_kdtrace.h. Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES is linked there and it is only used as a compile-time stub [0].
[0] immediately shows some new bug as DTRACE-derived support for debug in sfxge is broken and it was never really tested. As it was not including correctly opt_kdtrace.h before it was never enabled so it was kept broken for a while. Fix this by using a protection stub, leaving sfxge driver authors the responsibility for fixing it appropriately [1].
Sponsored by: EMC / Isilon storage division Discussed with: rstone [0] Reported by: rstone [1] Discussed with: philip
|
255040 |
29-Aug-2013 |
gibbs |
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.
|
231743 |
15-Feb-2012 |
gibbs |
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
|
230587 |
26-Jan-2012 |
ken |
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
|
214077 |
19-Oct-2010 |
gibbs |
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
|
196037 |
02-Aug-2009 |
attilio |
Make the newbus subsystem Giant free by adding the new newbus sxlock. The newbus lock is responsible for protecting newbus internIal structures, device states and devclass flags. It is necessary to hold it when all such datas are accessed. For the other operations, softc locking should ensure enough protection to avoid races.
Newbus lock is automatically held when virtual operations on the device and bus are invoked when loading the driver or when the suspend/resume take place. For other 'spourious' operations trying to access/modify the newbus topology, newbus lock needs to be automatically acquired and dropped.
For the moment Giant is also acquired in some key point (modules subsystem) in order to avoid problems before the 8.0 release as module handlers could make assumptions about it. This Giant locking should go just after the release happens.
Please keep in mind that the public interface can be expanded in order to provide more support, if there are really necessities at some point and also some bugs could arise as long as the patch needs a bit of further testing.
Bump __FreeBSD_version in order to reflect the newbus lock introduction.
Reviewed by: ed, hps, jhb, imp, mav, scottl No answer by: ariff, thompsa, yongari Tested by: pho, G. Trematerra <giovanni dot trematerra at gmail dot com>, Brandon Gooch <jamesbrandongooch at gmail dot com> Sponsored by: Yahoo! Incorporated Approved by: re (ksmith)
|
187830 |
28-Jan-2009 |
ed |
Last step of splitting up minor and unit numbers: remove minor().
Inside the kernel, the minor() function was responsible for obtaining the device minor number of a character device. Because we made device numbers dynamically allocated and independent of the unit number passed to make_dev() a long time ago, it was actually a misnomer. If you really want to obtain the device number, you should use dev2udev().
We already converted all the drivers to use dev2unit() to obtain the device unit number, which is still used by a lot of drivers. I've noticed not a single driver passes NULL to dev2unit(). Even if they would, its behaviour would make little sense. This is why I've removed the NULL check.
Ths commit removes minor(), minor2unit() and unit2minor() from the kernel. Because there was a naming collision with uminor(), we can rename umajor() and uminor() back to major() and minor(). This means that the makedev(3) manual page also applies to kernel space code now.
I suspect umajor() and uminor() isn't used that often in external code, but to make it easier for other parties to port their code, I've increased __FreeBSD_version to 800062.
|