r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE.
Reviewed by: royger
Approved by: kib (mentor, blanket)
Differential Revision: https://reviews.freebsd.org/D23638
BIO_READ and BIO_WRITE, we've handled this expanded syntax poorly in
drivers when the driver doesn't support a particular command. Do a
sweep and fix that.
Reported by: imp
If gnttab_grant_foreign_access() fails for any of the indirection
pages, the code breaks out of both the loops without freeing the local
variable indirectpages, causing a memory leak.
Submitted by: Pratyush Yadav <pratyush@freebsd.org>
Differential Review: https://reviews.freebsd.org/D16136
Length is an unsigned integer, so checking against < 0 doesn't make
sense. While there also make clear that a length of 0 always succeeds.
Submitted by: Pratyush Yadav <pratyush@freebsd.org>
Differential Review: https://reviews.freebsd.org/D16045
Uses of mallocarray(9).
The use of mallocarray(9) has rocketed the required swap to build FreeBSD.
This is likely caused by the allocation size attributes which put extra pressure
on the compiler.
Given that most of these checks are superfluous we have to choose better
where to use mallocarray(9). We still have more uses of mallocarray(9) but
hopefully this is enough to bring swap usage to a reasonable level.
Reported by: wosch
PR: 225197
Focus on code where we are doing multiplications within malloc(9). None of
these is likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.
This initial sweep only covers malloc(9) calls with M_NOWAIT. No good
reason but I started doing the changes before r327796 and at that time it
was convenient to make sure the sorrounding code could handle NULL values.
--Remove special-case handling of sparc64 bus_dmamap* functions.
Replace with a more generic mechanism that allows MD busdma
implementations to generate inline mapping functions by
defining WANT_INLINE_DMAMAP in <machine/bus_dma.h>. This
is currently useful for sparc64, x86, and arm64, which all
implement non-load dmamap operations as simple wrappers
around map objects which may be bus- or device-specific.
--Remove NULL-checked bus_dmamap macros. Implement the
equivalent NULL checks in the inlined x86 implementation.
For non-x86 platforms, these checks are a minor pessimization
as those platforms do not currently allow NULL maps. NULL
maps were originally allowed on arm64, which appears to have
been the motivation behind adding arm[64]-specific barriers
to bus_dma.h, but that support was removed in r299463.
--Simplify the internal interface used by the bus_dmamap_load*
variants and move it to bus_dma_internal.h
--Fix some drivers that directly include sys/bus_dma.h
despite the recommendations of bus_dma(9)
Reviewed by: kib (previous revision), marius
Differential Revision: https://reviews.freebsd.org/D10729
Call disk_gone when the backend switches to the "Closing" state and blkfront
still has pending users. This allows the disk to be detached, and will call
into xbd_closing by itself when the geom layout cleanup has finished.
Reported by: bapt
Tested by: manu
Reviewed by: bapt
Sponsored by: Citrix Systems R&D
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D10772
When running on Xen, it's possible that a suspend request to the hypervisor
fails (return from HYPERVISOR_suspend different than 0). This means that the
suspend hasn't succeed, and the resume procedure needs to properly handle this
case.
First of all, when such situation happens there's no need to reset the vector
callback, hypercall page, shared info, event channels or grant table, because
it's state is preserved. Also, the PV drivers don't need to be reset to the
initial state, since the connection with the backed has not been interrupted.
Submitted by: Liuyingdong <liuyingdong@huawei.com>
Reviewed by: royger
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D9635
feature_barrier and feature_flush variables. Otherwise, adjacent
variables on the stack, such as sector_size, may be overwritten, with
disastrous results.
Note that I did not see a good reason to revert the addition of zero
checks introduced in r310013. Better safe than sorry.
PR: 215209
Tested by: royger
MFC after: 3 days
non-zero sector size. Such a device would be a virtual disk of zero
bytes; clearly not useful, and not something we should try to attach.
As a fortuitous side effect, checking that these values are non-zero
here results in them not *becoming* zero later on the function. This
odd behaviour began with r309124 (clang 3.9.0) but is challenging to
debug; making any changes to this function whatsoever seems to affect
the llvm optimizer behaviour enough to make the unexpected zeroing of
the sector_size variable cease.
PR: 215209
Security: The potential for variables to unexpectedly become zero
has worrying consequences for security in general, but
not so much in this particular context.
by busdma to the blkfront driver must be an integer number of sectors,
and must be aligned in memory on a "sector" boundary.
Having these assertions yesterday would have made finding the bug fixed
in r293698 somewhat easier.
Using unmapped IO is really beneficial when running inside of a VM,
since it avoids IPIs to other vCPUs in order to invalidate the
mappings.
This patch adds unmapped IO support to blkfront. The following tests
results have been obtained when running on a Xen host without HAP:
PVHVM
3165.84 real 6354.17 user 4483.32 sys
PVHVM with unmapped IO
2099.46 real 4624.52 user 2967.38 sys
This is because when running using shadow page tables TLB flushes and
range invalidations are much more expensive, so using unmapped IO
provides a very important performance boost.
Sponsored by: Citrix Systems R&D
MFC after: 2 weeks
X-MFC-with: r290610
dev/xen/blkfront/blkfront.c:
- Add and announce support for unmapped IO.
The new load_ma implementation can cause dereferences when used with
certain drivers, back it out until the reason is found:
Fatal trap 12: page fault while in kernel mode
cpuid = 11; apic id = 03
fault virtual address = 0x30
fault code = supervisor read data, page not present
instruction pointer = 0x20:0xffffffff808a2d22
stack pointer = 0x28:0xfffffe07cc737710
frame pointer = 0x28:0xfffffe07cc737790
code segment = base 0x0, limit 0xfffff, type 0x1b
= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags = interrupt enabled, resume, IOPL = 0
current process = 13 (g_down)
trap number = 12
panic: page fault
cpuid = 11
KDB: stack backtrace:
#0 0xffffffff80641647 at kdb_backtrace+0x67
#1 0xffffffff80606762 at vpanic+0x182
#2 0xffffffff806067e3 at panic+0x43
#3 0xffffffff8084eef1 at trap_fatal+0x351
#4 0xffffffff8084f0e4 at trap_pfault+0x1e4
#5 0xffffffff8084e82f at trap+0x4bf
#6 0xffffffff80830d57 at calltrap+0x8
#7 0xffffffff8063beab at _bus_dmamap_load_ccb+0x1fb
#8 0xffffffff8063bc51 at bus_dmamap_load_ccb+0x91
#9 0xffffffff8042dcad at ata_dmaload+0x11d
#10 0xffffffff8042df7e at ata_begin_transaction+0x7e
#11 0xffffffff8042c18e at ataaction+0x9ce
#12 0xffffffff802a220f at xpt_run_devq+0x5bf
#13 0xffffffff802a17ad at xpt_action_default+0x94d
#14 0xffffffff802c0024 at adastart+0x8b4
#15 0xffffffff802a2e93 at xpt_run_allocq+0x193
#16 0xffffffff802c0735 at adastrategy+0xf5
#17 0xffffffff80554206 at g_disk_start+0x426
Uptime: 2m29s
Using unmapped IO is really beneficial when running inside of a VM,
since it avoids IPIs to other vCPUs in order to invalidate the
mappings.
This patch adds unmapped IO support to blkfront. The following tests
results have been obtained when running on a Xen host without HAP:
PVHVM
3165.84 real 6354.17 user 4483.32 sys
PVHVM with unmapped IO
2099.46 real 4624.52 user 2967.38 sys
This is because when running using shadow page tables TLB flushes and
range invalidations are much more expensive, so using unmapped IO
provides a very important performance boost.
Sponsored by: Citrix Systems R&D
MFC after: 2 weeks
X-MFC-with: r289834
Pull the latest headers for Xen which allow us to add support for ARM and
use new features in FreeBSD.
This is a verbatim copy of the xen/include/public so every headers which
don't exits anymore in the Xen repositories have been dropped.
Note the interface version hasn't been bumped, it will be done in a
follow-up. Although, it requires fix in the code to get it compiled:
- sys/xen/xen_intr.h: evtchn_port_t is already defined in the headers so
drop it.
- {amd64,i386}/include/intr_machdep.h: NR_EVENT_CHANNELS now depends on
xen/interface/event_channel.h, so include it.
- {amd64,i386}/{amd64,i386}/support.S: It's not neccessary to include
machine/intr_machdep.h. This is also fixing build compilation with the
new headers.
- dev/xen/blkfront/blkfront.c: The typedef for blkif_request_segmenthas
been dropped. So directly use struct blkif_request_segment
Finally, modify xen/interface/xen-compat.h to throw a preprocessing error if
__XEN_INTERFACE_VERSION__ is not set. This is allow us to catch any file
where xen/xen-os.h is not correctly included.
Submitted by: Julien Grall <julien.grall@citrix.com>
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D3805
Sponsored by: Citrix Systems R&D
Introduce two new loader tunnables that can be used to disable PV disks and
PV nics at boot time. They default to 0 and should be set to 1 (or any
number different than 0) in order to disable the PV devices:
hw.xen.disable_pv_disks=1
hw.xen.disable_pv_nics=1
In /boot/loader.conf will disable both PV disks and nics.
Sponsored by: Citrix Systems R&D
Tested by: Karl Pielorz <kpielorz_lst@tdx.co.uk>
MFC after: 1 week
use vtophys() directly instead of vtomach() and retire the no-longer-used
headers <machine/xenfunc.h> and <machine/xenvar.h>.
Reported by: bde (stale bits in <machine/xenfunc.h>)
Reviewed by: royger (earlier version)
Differential Revision: https://reviews.freebsd.org/D3266
the blkfront driver to perform I/Os of up to 2 MB, subject to support from
the blkback to which it is connected and the initiation of such large I/Os
by the rest of the kernel. In practice, the I/O size is increased from 40 kB
to 128 kB.
The changes to xen/interface/io/blkif.h consist merely of merging updates
from the upstream Xen repository.
In dev/xen/blkfront/block.h we add some convenience macros and structure
fields used for indirect-page I/Os: The device records its negotiated limit
on the number of indirect pages used, while each I/O command structure gains
permanently allocated page(s) for indirect page references and the Xen grant
references for those pages.
In dev/xen/blkfront/blkfront.c we now check in xbd_queue_cb whether a request
is small enough to handle without an indirection page, and either follow the
previous behaviour or use new code for issuing an indirect segment I/O. In
xbd_connect we read the size of indirect segment I/Os supported by the backend
and select the maximum size we will use; then allocate the pages and Xen grant
references for each I/O command structure. In xbd_free those grants and pages
are released.
A new loader tunable, hw.xbd.xbd_enable_indirect, can be set to 0 in order to
disable this functionality; it works by pretending that the backend does not
support this feature. Some backends exhibit a loss of performance with large
I/Os, so users may wish to test with and without this functionality enabled.
Reviewed by: royger
MFC after: 3 days
Relnotes: yes
xbd_initialize to xbd_connect. Both of these initialization steps need
to know what the maximum possible I/O size will be, and when we gain
support for indirect segment I/Os we won't know that value until we
reach xbd_connect. Since none of this data is used before xbd_connect
completes, moving the initialization is harmless.
This commit should not result in any functional changes.
into blkif segments, and moving it into a new function. This will be used
by upcoming support for indirect-segment blkif requests.
This commit should not result in any functional changes.
* nsegs must be at most BLKIF_MAX_SEGMENTS_PER_REQUEST (since we specify
that limit to bus_dma_tag_create), so KASSERT that rather than silently
adjusting the request.
* block_segs is now a synonym for nsegs, so garbage collect that variable.
* nsegs is never read during or after the while loop, so remove the dead
decrement from the loop.
These were all left behind from the pre-r284296 support for a "segment
block" extension.
The FreeBSD extension adds a new request type, called blkif_segment_block
which has a size of 112bytes for both i386 and amd64. This is fine on
amd64, since requests have a size of 112B there also. But this is not true
for i386, where requests have a size of 108B. So on i386 we basically
overrun the ring slot when queuing a request of type blkif_segment_block_t,
which is very bad.
Remove this extension (including a cleanup of the public blkif.h header
file) from blkfront and blkback.
Sponsored by: Citrix Systems R&D
Tested-by: cperciva
Current busdma code for unmapped bios will not properly align the segment
size, causing corruption on blkfront devices. Revert the commit until
busdma code is fixed.
Reported by: mav
MFC after: 1 day
Using unmapped IO is really beneficial when running inside of a VM,
since it avoids IPIs to other vCPUs in order to invalidate the
mappings.
This patch adds unmapped IO support to blkfront. The following tests
results have been obtained when running on a Xen host without HAP:
PVHVM
3165.84 real 6354.17 user 4483.32 sys
PVHVM with unmapped IO
2099.46 real 4624.52 user 2967.38 sys
This is because when running using shadow page tables TLB flushes and
range invalidations are much more expensive, so using unmapped IO
provides a very important performance boost.
Sponsored by: Citrix Systems R&D
Tested by: robak
MFC after: 1 week
PR: 191173
dev/xen/blkfront/blkfront.c:
- Add and announce support for unmapped IO.
prior releases.
Submitted by: Roger Pau Monné
Sponsored by: Citrix Systems R&D
Reviewed by: gibbs
Approved by: re (gjb)
sys/dev/xen/blkfront/blkfront.c:
On XenServer versions up to an including 6.2, paravirtualized
CDROM support is broken. When running in an HVM domain,
ignore paravirtualized instances of CDROM media, and instead
rely on native drivers attaching to emulated hardware. This
functions correctly on all currently known Xen based
platforms.
value. Some hosts do not publish "extended" disk IDs via virtual-device in
an attempt to avoid confusing old blkfront drivers, and without this change
we failed to attach such disks.
In particular, this commit allows all 24 ephemeral disks on EC2 hs1.8xlarge
instances to be used, instead of only the first 15.
MFC after: 3 days
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.
support cache flush and write barrier commands.
sys/dev/xen/blkfront/block.h:
Add per-command flag that specifies that the I/O queue must
be frozen after this command is dispatched. This is used
to implement "single-stepping".
Remove the unused per-command flag that indicates a polled
command.
Add block device instance flags to record backend features.
Add a block device instance flag to indicate the I/O queue
is frozen until all outstanding I/O completes.
Enhance the queue API to allow the number of elements in a
queue to be interrogated.
Prefer "inline" to "__inline".
sys/dev/xen/blkfront/blkfront.c:
Formalize queue freeze semantics by adding methods for both
global and command-associated queue freezing.
Provide mechanism to freeze the I/O queue until all outstanding
I/O completes. Use this to implement barrier semantics
(BIO_ORDERED) when the backend does not support
BLKIF_OP_WRITE_BARRIER commands.
Implement BIO_FLUSH as either a BLKIF_OP_FLUSH_DISKCACHE
command or a 0 byte write barrier. Currently, all publicly
available backends perform a diskcache flush when processing
barrier commands, and this frontend behavior matches what
is done in Linux.
Simplify code by using new queue length API.
Report backend features during device attach and via sysctl.
Submitted by: Roger Pau Monné
Submitted by: gibbs (Merge with new driver queue API, sysctl support)
only re-enable I/O when all reasons have cleared.
sys/dev/xen/blkfront/block.h:
In the block front driver softc, replace the boolean
XBDF_FROZEN flag with a count of commands and driver global
issues that freeze the I/O queue. So long xbd_qfrozen_cnt
is non-zero, I/O is halted.
Add flags to xbd_flags for tracking grant table entry and
free command resource shortages. Each of these classes can
increment xbd_qfrozen_cnt at most once.
Add a command flag (XBDCF_ASYNC_MAPPING) that is set whenever
the initial mapping attempt of a command fails with EINPROGRESS.
sys/dev/xen/blkfront/blkfront.c:
In xbd_queue_cb(), use new XBDCF_ASYNC_MAPPING flag to definitively
know if an async bus dmamap load has occurred.
Add xbd_freeze() and xbd_thaw() helper methods for managing
xbd_qfrozen_cnt and use them to implement all queue freezing logic.
Add missing "thaw" to restart I/O processing once grant references
become available.
Sponsored by: Spectra Logic Corporation
scheme for defining inline command queuing functions.
Prefer enums to #defines.
sys/dev/xen/blkfront/block.h
Replace inline function generation performed by the
XBDQ_COMMAND_QUEUE() macro with single instances of each
inline function (init, enqueue, dequeue, remove). This was
made possible by using queue indexes instead of bit flags
in the command structure, and passing the index enum as
an argument to the functions.
Improve panic/assert messages in the queue functions.
Combine queue data and stats into a single data structure
and declare an array of them instead of each queue individually.
Convert command flags, softc state, and softc flags to enums.
sys/dev/xen/blkfront/blkfront.c
Mechanical adjustments for new queue api.
Sponsored by: Spectra Logic Corporation
MFC after: 1 week
Remove local, and incorrect, definition for the value of an invalid
grant reference.
Extract ring cleanup code into xbd_free_ring() function for
symetry with xbd_alloc_ring(). This process also eliminated
an initialized but unused variable.
Sponsored by: Spectra Logic Corporation
MFC after: 1 week
o Group functions by by their functionality.
o Remove superfluous declarations.
o Remove more unused (#ifdef'd out) code.
Sponsored by: Spectra Logic Corporation
o This driver is the "xbd" driver, not the "blkfront", "blkif", "xbf", or
"xb" driver. Use the "xbd_" naming conventions for all functions,
structures, and constants.
o The prevailing convention for structure fields in this driver is to
prefix them with an abreviation of the structure type. Update
"recently added" fields to match this style.
o Remove unused data structures.
o Remove superfluous casts.
o Make a pass over the whole driver and bring it closer to
style(9) conformance.
Sponsored by: Spectra Logic Corporation
MFC after: 1 week
a da(4) instance going away while GEOM is still probing it.
In this case, the GEOM disk class instance has been created by
disk_create(), and the taste of the disk is queued in the GEOM
event queue.
While that event is queued, the da(4) instance goes away. When the
open call comes into the da(4) driver, it dereferences the freed
(but non-NULL) peripheral pointer provided by GEOM, which results
in a panic.
The solution is to add a callback to the GEOM disk code that is
called when all of its resources are cleaned up. This is
implemented inside GEOM by adding an optional callback that is
called when all consumers have detached from a provider, and the
provider is about to be deleted.
scsi_cd.c,
scsi_da.c: In the register routine for the cd(4) and da(4)
routines, acquire a reference to the CAM peripheral
instance just before we call disk_create().
Use the new GEOM disk d_gone() callback to register
a callback (dadiskgonecb()/cddiskgonecb()) that
decrements the peripheral reference count once GEOM
has finished cleaning up its resources.
In the cd(4) driver, clean up open and close
behavior slightly. GEOM makes sure we only get one
open() and one close call, so there is no need to
set an open flag and decrement the reference count
if we are not the first open.
In the cd(4) driver, use cam_periph_release_locked()
in a couple of error scenarios to avoid extra mutex
calls.
geom.h: Add a new, optional, providergone callback that
is called when a provider is about to be deleted.
geom_disk.h: Add a new d_gone() callback to the GEOM disk
interface.
Bump the DISK_VERSION to version 2. This probably
should have been done after a couple of previous
changes, especially the addition of the d_getattr()
callback.
geom_disk.c: Add a providergone callback for the disk class,
g_disk_providergone(), that calls the user's
d_gone() callback if it exists.
Bump the DISK_VERSION to 2.
geom_subr.c: In g_destroy_provider(), call the providergone
callback if it has been provided.
In g_new_geomf(), propagate the class's
providergone callback to the new geom instance.
blkfront.c: Callers of disk_create() are supposed to pass in
DISK_VERSION, not an explicit disk API version
number. Update the blkfront driver to do that.
disk.9: Update the disk(9) man page to include information
on the new d_gone() callback, as well as the
previously added d_getattr() callback, d_descr
field, and HBA PCI ID fields.
MFC after: 5 days
XenServer configurations that advertise the multi-page ring extension,
but only allow a single page of ring space.
sys/dev/xen/blkfront/blkfront.c:
If only one page of ring space is being used, do not publish
in the XenStore the number of pages in use (1), via either
of the supported multi-page ring extension schemes.
Single page operation is the same with or without the
ring-page extension being negotiated. Relying on the
legacy behavior avoids an incompatible difference in how
the two ring-page extension schemes that are out in the
wild, deal with the base case of a single page. The
Amazon/Red Hat drivers use the same XenStore variable as
if the extension was not negotiated. The Citrix drivers
assume the new ring reference XenStore variables will be
available
Reported by: Oliver Schonefeld <schonefeld@ids-mannheim.de>
MFC after: 3 days
remaining drivers that haven't been converted have various problems or
complexities that will be dealt with later. This list includes:
hptrr, hptmv, hpt27xx - device aggregation across multiple parents
drm - want to talk to the maintainer first
tsec, sec - Openfirmware devices, not sure if changes are warranted
fatm - Done except for unused testing code
usb - want to talk to the maintainer first
ce, cp, ctau, cx - Significant driver changes needed to convey parent info
There are also devices tucked into architecture subtrees that I'll leave
for the respective maintainers to deal with.
The previous code did not limit the I/O request size based on
the maximum number of segments supported by the back-end. In
current practice, since the only back-end supporting chained
requests is the FreeBSD implementation, this limit was never
exceeded.
sys/dev/xen/blkfront/block.h:
Add two macros, XBF_SEGS_TO_SIZE() and XBF_SIZE_TO_SEGS(),
to centralize the logic of reserving a segment to deal with
non-page-aligned I/Os.
sys/dev/xen/blkfront/blkfront.c:
o When negotiating transfer parameters, limit the
max_request_size we use and publish, if it is greater
than the maximum, unaligned, I/O we can support with
the number of segments advertised by the backend.
o Don't unilaterally reduce the I/O size published to
the disk layer by a single page. max_request_size
is already properly limited in the transfer parameter
negotiation code.
o Fix typos in printf strings:
"max_requests_segments" -> "max_request_segments"
"specificed" -> "specified"
MFC after: 1 day
