summaryrefslogtreecommitdiff
path: root/block/Kconfig
AgeCommit message (Collapse)Author
2022-03-07block: add pi for extended integrityKeith Busch
The NVMe specification defines new data integrity formats beyond the t10 tuple. Add support for the specification defined CRC64 formats, assuming the reference tag does not need to be split with the "storage tag". Cc: Hannes Reinecke <hare@suse.de> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20220303201312.3255347-8-kbusch@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-27block: default BLOCK_LEGACY_AUTOLOAD to yChristoph Hellwig
As Luis reported, losetup currently doesn't properly create the loop device without this if the device node already exists because old scripts created it manually. So default to y for now and remove the aggressive removal schedule. Reported-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220225181440.1351591-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-16blk-mq: make the blk-mq stacking code optionalChristoph Hellwig
The code to stack blk-mq drivers is only used by dm-multipath, and will preferably stay that way. Make it optional and only selected by device mapper, so that the buildbots more easily catch abuses like the one that slipped in in the ufs driver in the last merged window. Another positive side effects is that kernel builds without device mapper shrink a little bit as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220215100540.3892965-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02block: deprecate autoloading based on dev_tChristoph Hellwig
Make the legacy dev_t based autoloading optional and add a deprecation warning. This kind of autoloading has ceased to be useful about 20 years ago. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220104071647.164918-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-16block: only build the icq tracking code when neededChristoph Hellwig
Only bfq needs to code to track icq, so make it conditional. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211209063131.18537-12-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: move menu "Partition type" to block/partitions/KconfigMasahiro Yamada
Move the menu to the relevant place. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210927140000.866249-4-masahiroy@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: simplify Kconfig filesMasahiro Yamada
Everything under block/ depends on BLOCK. BLOCK_HOLDER_DEPRECATED is selected from drivers/md/Kconfig, which is entirely dependent on BLOCK. Extend the 'if BLOCK' ... 'endif' so it covers the whole block/Kconfig. Also, clean up the definition of BLOCK_COMPAT and BLK_MQ_PCI because COMPAT and PCI are boolean. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210927140000.866249-3-masahiroy@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-18block: remove redundant =y from BLK_CGROUP dependencyMasahiro Yamada
CONFIG_BLK_CGROUP is a boolean option, that is, its value is 'y' or 'n'. The comparison to 'y' is redundant. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210927140000.866249-2-masahiroy@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-02Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, qla2xxx, target, smartpqi, lpfc, mpt3sas). The core change causing the most churn was replacing the command request field request with a macro, allowing us to offset map to it and remove the redundant field; the same was also done for the tag field. The most impactful change is the final removal of scsi_ioctl, which has been deprecated for over a decade" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (293 commits) scsi: ufs: Fix ufshcd_request_sense_async() for Samsung KLUFG8RHDA-B2D1 scsi: ufs: ufs-exynos: Fix static checker warning scsi: mpt3sas: Use the proper SCSI midlayer interfaces for PI scsi: lpfc: Use the proper SCSI midlayer interfaces for PI scsi: lpfc: Copyright updates for 14.0.0.1 patches scsi: lpfc: Update lpfc version to 14.0.0.1 scsi: lpfc: Add bsg support for retrieving adapter cmf data scsi: lpfc: Add cmf_info sysfs entry scsi: lpfc: Add debugfs support for cm framework buffers scsi: lpfc: Add support for maintaining the cm statistics buffer scsi: lpfc: Add rx monitoring statistics scsi: lpfc: Add support for the CM framework scsi: lpfc: Add cmfsync WQE support scsi: lpfc: Add support for cm enablement buffer scsi: lpfc: Add cm statistics buffer support scsi: lpfc: Add EDC ELS support scsi: lpfc: Expand FPIN and RDF receive logging scsi: lpfc: Add MIB feature enablement support scsi: lpfc: Add SET_HOST_DATA mbox cmd to pass date/time info to firmware scsi: fc: Add EDC ELS definition ...
2021-08-09block: make the block holder code optionalChristoph Hellwig
Move the block holder code into a separate file as it is not in any way related to the other block_dev.c code, and add a new selectable config option for it so that we don't have to build it without any remapped drivers selected. The Kconfig symbol contains a _DEPRECATED suffix to match the comments added in commit 49731baa41df ("block: restore multiple bd_link_disk_holder() support"). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-02block: remove cmdline-parser.cChristoph Hellwig
cmdline-parser.c is only used by the cmdline faux partition format, so merge the code into that and avoid an indirect call. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210728053756.409654-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-07-28scsi: core: Rename CONFIG_BLK_SCSI_REQUEST to CONFIG_SCSI_COMMONChristoph Hellwig
CONFIG_BLK_SCSI_REQUEST is rather misnamed as it enables building a small amount of code shared by the SCSI initiator, target, and consumers of the scsi_request passthrough API. Rename it and also allow building it as a module. [mkp: add module license] Link: https://lore.kernel.org/r/20210724072033.1284840-20-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-07-28scsi: bsg: Move bsg_scsi_ops to drivers/scsi/Christoph Hellwig
Move the SCSI-specific bsg code in the SCSI midlayer instead of in the common bsg code. This just keeps the common bsg code block/ and also allows building it as a module. Link: https://lore.kernel.org/r/20210724072033.1284840-15-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-07-04scsi: blkcg: Fix application ID config optionsMartin K. Petersen
Commit d2bcbeab4200 ("scsi: blkcg: Add app identifier support for blkcg") introduced an FC_APPID config option under SCSI. However, the added config option is not used anywhere. Simply remove it. The block layer BLK_CGROUP_FC_APPID config option is what actually controls whether the application ID code should be built or not. Make this option dependent on NVMe over FC since that is currently the only transport which supports the capability. Fixes: d2bcbeab4200 ("scsi: blkcg: Add app identifier support for blkcg") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-02Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull SCSI updates from James Bottomley: "This series consists of the usual driver updates (ufs, ibmvfc, megaraid_sas, lpfc, elx, mpi3mr, qedi, iscsi, storvsc, mpt3sas) with elx and mpi3mr being new drivers. The major core change is a rework to drop the status byte handling macros and the old bit shifted definitions and the rest of the updates are minor fixes" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (287 commits) scsi: aha1740: Avoid over-read of sense buffer scsi: arcmsr: Avoid over-read of sense buffer scsi: ips: Avoid over-read of sense buffer scsi: ufs: ufs-mediatek: Add missing of_node_put() in ufs_mtk_probe() scsi: elx: libefc: Fix IRQ restore in efc_domain_dispatch_frame() scsi: elx: libefc: Fix less than zero comparison of a unsigned int scsi: elx: efct: Fix pointer error checking in debugfs init scsi: elx: efct: Fix is_originator return code type scsi: elx: efct: Fix link error for _bad_cmpxchg scsi: elx: efct: Eliminate unnecessary boolean check in efct_hw_command_cancel() scsi: elx: efct: Do not use id uninitialized in efct_lio_setup_session() scsi: elx: efct: Fix error handling in efct_hw_init() scsi: elx: efct: Remove redundant initialization of variable lun scsi: elx: efct: Fix spelling mistake "Unexected" -> "Unexpected" scsi: lpfc: Fix build error in lpfc_scsi.c scsi: target: iscsi: Remove redundant continue statement scsi: qla4xxx: Remove redundant continue statement scsi: ppa: Switch to use module_parport_driver() scsi: imm: Switch to use module_parport_driver() scsi: mpt3sas: Fix error return value in _scsih_expander_add() ...
2021-06-21block: Introduce the ioprio rq-qos policyBart Van Assche
Introduce an rq-qos policy that assigns an I/O priority to requests based on blk-cgroup configuration settings. This policy has the following advantages over the ioprio_set() system call: - This policy is cgroup based so it has all the advantages of cgroups. - While ioprio_set() does not affect page cache writeback I/O, this rq-qos controller affects page cache writeback I/O for filesystems that support assiociating a cgroup with writeback I/O. See also Documentation/admin-guide/cgroup-v2.rst. Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20210618004456.7280-5-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-21block/Kconfig: Make the BLK_WBT and BLK_WBT_MQ entries consecutiveBart Van Assche
These entries were consecutive at the time of their introduction but are no longer consecutive. Make these again consecutive. Additionally, modify the help text since it refers to blk-mq and since the legacy block layer has been removed. Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Link: https://lore.kernel.org/r/20210618004456.7280-2-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-10scsi: blkcg: Add app identifier support for blkcgMuneendra Kumar
Add a unique application identifier (i.e fc_app_id member) in blkcg. This allows identification of traffic belonging to an specific both on the host and in the fabric infrastructure. As an example, this allows the storage stack to uniquely identify traffic belong to particular virtual machine. Link: https://lore.kernel.org/r/20210608043556.274139-3-muneendra.kumar@broadcom.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-09-01blk-wbt: Remove obsolete multiqueue I/O scheduling commentDanny Lin
This comment was added before the multiqueue I/O scheduler framework was introduced; multiqueue has support for I/O scheduling now, so this obsolete comment can be removed. Signed-off-by: Danny Lin <danny@kdrag0n.dev> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-08nvme: support for zoned namespacesKeith Busch
Add support for NVM Express Zoned Namespaces (ZNS) Command Set defined in NVM Express TP4053. Zoned namespaces are discovered based on their Command Set Identifier reported in the namespaces Namespace Identification Descriptor list. A successfully discovered Zoned Namespace will be registered with the block layer as a host managed zoned block device with Zone Append command support. A namespace that does not support append is not supported by the driver. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Javier González <javier.gonz@samsung.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com> Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Keith Busch <keith.busch@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-14treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-14block: blk-crypto-fallback for Inline EncryptionSatya Tangirala
Blk-crypto delegates crypto operations to inline encryption hardware when available. The separately configurable blk-crypto-fallback contains a software fallback to the kernel crypto API - when enabled, blk-crypto will use this fallback for en/decryption when inline encryption hardware is not available. This lets upper layers not have to worry about whether or not the underlying device has support for inline encryption before deciding to specify an encryption context for a bio. It also allows for testing without actual inline encryption hardware - in particular, it makes it possible to test the inline encryption code in ext4 and f2fs simply by running xfstests with the inlinecrypt mount option, which in turn allows for things like the regular upstream regression testing of ext4 to cover the inline encryption code paths. For more details, refer to Documentation/block/inline-encryption.rst. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-14block: Keyslot Manager for Inline EncryptionSatya Tangirala
Inline Encryption hardware allows software to specify an encryption context (an encryption key, crypto algorithm, data unit num, data unit size) along with a data transfer request to a storage device, and the inline encryption hardware will use that context to en/decrypt the data. The inline encryption hardware is part of the storage device, and it conceptually sits on the data path between system memory and the storage device. Inline Encryption hardware implementations often function around the concept of "keyslots". These implementations often have a limited number of "keyslots", each of which can hold a key (we say that a key can be "programmed" into a keyslot). Requests made to the storage device may have a keyslot and a data unit number associated with them, and the inline encryption hardware will en/decrypt the data in the requests using the key programmed into that associated keyslot and the data unit number specified with the request. As keyslots are limited, and programming keys may be expensive in many implementations, and multiple requests may use exactly the same encryption contexts, we introduce a Keyslot Manager to efficiently manage keyslots. We also introduce a blk_crypto_key, which will represent the key that's programmed into keyslots managed by keyslot managers. The keyslot manager also functions as the interface that upper layers will use to program keys into inline encryption hardware. For more information on the Keyslot Manager, refer to documentation found in block/keyslot-manager.c and linux/keyslot-manager.h. Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30blk-iocost: account for IO size when testing latenciesTejun Heo
On each IO completion, iocost decides whether the IO met or missed its latency target. Currently, the targets are fixed numbers per IO type. While this can be good enough for loose latency targets way higher than typical completion latencies, the effect of IO size makes it difficult to tighten the latency target - a target adequate for 4k IOs might be too tight for 512k IOs and vice-versa. iocost already has all the necessary information to account for different IO sizes when testing whether the latency target is met as iocost can calculate the size vtime cost of a given IO. This patch updates the completion path to calculate the size vtime cost of the IO, deduct the nsec equivalent from the observed latency and use the adjusted value to decide whether the target is met. This makes latency targets independent from IO size and enables determining adequate latency targets with fixed size fio runs. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-06block: Allow t10-pi to be modularHerbert Xu
Currently t10-pi can only be built into the block layer which via crc-t10dif pulls in a whole chunk of the Crypto API. In fact all users of t10-pi work as modules and there is no reason for it to always be built-in. This patch adds a new hidden option for t10-pi that is selected automatically based on BLK_DEV_INTEGRITY and whether the users of t10-pi are built-in or not. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-07blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTATTejun Heo
blkg_rwstat is now only used by bfq-iosched and blk-throtl when on cgroup1. Let's move it into its own files and gate it behind a config option. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-28blkcg: implement blk-iocostTejun Heo
This patchset implements IO cost model based work-conserving proportional controller. While io.latency provides the capability to comprehensively prioritize and protect IOs depending on the cgroups, its protection is binary - the lowest latency target cgroup which is suffering is protected at the cost of all others. In many use cases including stacking multiple workload containers in a single system, it's necessary to distribute IO capacity with better granularity. One challenge of controlling IO resources is the lack of trivially observable cost metric. The most common metrics - bandwidth and iops - can be off by orders of magnitude depending on the device type and IO pattern. However, the cost isn't a complete mystery. Given several key attributes, we can make fairly reliable predictions on how expensive a given stream of IOs would be, at least compared to other IO patterns. The function which determines the cost of a given IO is the IO cost model for the device. This controller distributes IO capacity based on the costs estimated by such model. The more accurate the cost model the better but the controller adapts based on IO completion latency and as long as the relative costs across differents IO patterns are consistent and sensible, it'll adapt to the actual performance of the device. Currently, the only implemented cost model is a simple linear one with a few sets of default parameters for different classes of device. This covers most common devices reasonably well. All the infrastructure to tune and add different cost models is already in place and a later patch will also allow using bpf progs for cost models. Please see the top comment in blk-iocost.c and documentation for more details. v2: Rebased on top of RQ_ALLOC_TIME changes and folded in Rik's fix for a divide-by-zero bug in current_hweight() triggered by zero inuse_sum. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-08-28blk-mq: add optional request->alloc_time_nsTejun Heo
There are currently two start time timestamps - start_time_ns and io_start_time_ns. The former marks the request allocation and and the second issue-to-device time. The planned io.weight controller needs to measure the total time bios take to execute after it leaves rq_qos including the time spent waiting for request to become available, which can easily dominate on saturated devices. This patch adds request->alloc_time_ns which records when the request allocation attempt started. As it isn't used for the usual stats, make it optional behind CONFIG_BLK_RQ_ALLOC_TIME and QUEUE_FLAG_RQ_ALLOC_TIME so that it can be compiled out when there are no users and it's active only on queues which need it even when compiled in. v2: s/pre_start_time/alloc_time/ and add CONFIG_BLK_RQ_ALLOC_TIME gating as suggested by Jens. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-15docs: cgroup-v1: add it to the admin-guide bookMauro Carvalho Chehab
Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: block: convert to ReSTMauro Carvalho Chehab
Rename the block documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-08Merge branch 'for-5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Documentation updates and the addition of cgroup_parse_float() which will be used by new controllers including blk-iocost" * 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: convert docs to ReST and rename to *.rst cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS cgroup: add cgroup_parse_float()
2019-06-14docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab
Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-13block: force select mq-deadline for zoned block devicesDamien Le Moal
In most use cases of zoned block devices (aka SMR disks), the mq-deadline scheduler is mandatory as it implements sequential write command processing guarantees with zone write locking. So make sure that this scheduler is always enabled if CONFIG_BLK_DEV_ZONED is selected. Tested-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-06block: remove CONFIG_LBDAFChristoph Hellwig
Currently support for 64-bit sector_t and blkcnt_t is optional on 32-bit architectures. These types are required to support block device and/or file sizes larger than 2 TiB, and have generally defaulted to on for a long time. Enabling the option only increases the i386 tinyconfig size by 145 bytes, and many data structures already always use 64-bit values for their in-core and on-disk data structures anyway, so there should not be a large change in dynamic memory usage either. Dropping this option removes a somewhat weird non-default config that has cause various bugs or compiler warnings when actually used. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-29Merge tag 'kconfig-v4.21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kconfig updates from Masahiro Yamada: - support -y option for merge_config.sh to avoid downgrading =y to =m - remove S_OTHER symbol type, and touch include/config/*.h files correctly - fix file name and line number in lexer warnings - fix memory leak when EOF is encountered in quotation - resolve all shift/reduce conflicts of the parser - warn no new line at end of file - make 'source' statement more strict to take only string literal - rewrite the lexer and remove the keyword lookup table - convert to SPDX License Identifier - compile C files independently instead of including them from zconf.y - fix various warnings of gconfig - misc cleanups * tag 'kconfig-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits) kconfig: surround dbg_sym_flags with #ifdef DEBUG to fix gconf warning kconfig: split images.c out of qconf.cc/gconf.c to fix gconf warnings kconfig: add static qualifiers to fix gconf warnings kconfig: split the lexer out of zconf.y kconfig: split some C files out of zconf.y kconfig: convert to SPDX License Identifier kconfig: remove keyword lookup table entirely kconfig: update current_pos in the second lexer kconfig: switch to ASSIGN_VAL state in the second lexer kconfig: stop associating kconf_id with yylval kconfig: refactor end token rules kconfig: stop supporting '.' and '/' in unquoted words treewide: surround Kconfig file paths with double quotes microblaze: surround string default in Kconfig with double quotes kconfig: use T_WORD instead of T_VARIABLE for variables kconfig: use specific tokens instead of T_ASSIGN for assignments kconfig: refactor scanning and parsing "option" properties kconfig: use distinct tokens for type and default properties kconfig: remove redundant token defines kconfig: rename depends_list to comment_option_list ...
2018-12-22treewide: surround Kconfig file paths with double quotesMasahiro Yamada
The Kconfig lexer supports special characters such as '.' and '/' in the parameter context. In my understanding, the reason is just to support bare file paths in the source statement. I do not see a good reason to complicate Kconfig for the room of ambiguity. The majority of code already surrounds file paths with double quotes, and it makes sense since file paths are constant string literals. Make it treewide consistent now. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ingo Molnar <mingo@kernel.org>
2018-11-07blk-wbt: kill check for legacy queue typeJens Axboe
Everything is blk-mq at this point, so it doesn't make any sense to have this option available as it does nothing. Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-10-10block: remove redundant 'default n' from Kconfig-sBartlomiej Zolnierkiewicz
'default n' is the default value for any bool or tristate Kconfig setting so there is no need to write it explicitly. Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO is not set' for visible symbols") the Kconfig behavior is the same regardless of 'default n' being present or not: ... One side effect of (and the main motivation for) this change is making the following two definitions behave exactly the same: config FOO bool config FOO bool default n With this change, neither of these will generate a '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied). That might make it clearer to people that a bare 'default n' is redundant. ... Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-26block: Move power management code into a new source fileBart Van Assche
Move the code for runtime power management from blk-core.c into the new source file blk-pm.c. Move the corresponding declarations from <linux/blkdev.h> into <linux/blk-pm.h>. For CONFIG_PM=n, leave out the declarations of the functions that are not used in that mode. This patch not only reduces the number of #ifdefs in the block layer core code but also reduces the size of header file <linux/blkdev.h> and hence should help to reduce the build time of the Linux kernel if CONFIG_PM is not defined. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09block: introduce blk-iolatency io controllerJosef Bacik
Current IO controllers for the block layer are less than ideal for our use case. The io.max controller is great at hard limiting, but it is not work conserving. This patch introduces io.latency. You provide a latency target for your group and we monitor the io in short windows to make sure we are not exceeding those latency targets. This makes use of the rq-qos infrastructure and works much like the wbt stuff. There are a few differences from wbt - It's bio based, so the latency covers the whole block layer in addition to the actual io. - We will throttle all IO types that comes in here if we need to. - We use the mean latency over the 100ms window. This is because writes can be particularly fast, which could give us a false sense of the impact of other workloads on our protected workload. - By default there's no throttling, we set the queue_depth to INT_MAX so that we can have as many outstanding bio's as we're allowed to. Only at throttle time do we pay attention to the actual queue depth. - We backcharge cgroups for root cg issued IO and induce artificial delays in order to deal with cases like metadata only or swap heavy workloads. In testing this has worked out relatively well. Protected workloads will throttle noisy workloads down to 1 io at time if they are doing normal IO on their own, or induce up to a 1 second delay per syscall if they are doing a lot of root issued IO (metadata/swap IO). Our testing has revolved mostly around our production web servers where we have hhvm (the web server application) in a protected group and everything else in another group. We see slightly higher requests per second (RPS) on the test tier vs the control tier, and much more stable RPS across all machines in the test tier vs the control tier. Another test we run is a slow memory allocator in the unprotected group. Before this would eventually push us into swap and cause the whole box to die and not recover at all. With these patches we see slight RPS drops (usually 10-15%) before the memory consumer is properly killed and things recover within seconds. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=nBart Van Assche
Exclude zoned block device members from struct request_queue for CONFIG_BLK_DEV_ZONED == n. Avoid breaking the build by only building the code that uses these struct request_queue members if CONFIG_BLK_DEV_ZONED != n. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-15docs: Fix some broken referencesMauro Carvalho Chehab
As we move stuff around, some doc references are broken. Fix some of them via this script: ./scripts/documentation-file-ref-check --fix Manually checked if the produced result is valid, removing a few false-positives. Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Jonathan Corbet <corbet@lwn.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-08block: Add rdma affinity based queue mapping helperSagi Grimberg
Like pci and virtio, we add a rdma helper for affinity spreading. This achieves optimal mq affinity assignments according to the underlying rdma device affinity maps. Reviewed-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-05-12Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "Incremental fixes and a small feature addition on top of the main libnvdimm 4.12 pull request: - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX. The size regression is fixed by moving all dax helpers into the dax-core and only specifying "select DAX" for FS_DAX and dax-capable drivers. He also asked for clarification of the NR_DEV_DAX config option which, on closer look, does not need to be a config option at all. Mike also throws in a DEV_DAX_PMEM fixup for good measure. - Ben's attention to detail on -stable patch submissions caught a case where the recent fixes to arch_copy_from_iter_pmem() missed a condition where we strand dirty data in the cache. This is tagged for -stable and will also be included in the rework of the pmem api to a proposed {memcpy,copy_user}_flushcache() interface for 4.13. - Vishal adds a feature that missed the initial pull due to pending review feedback. It allows the kernel to clear media errors when initializing a BTT (atomic sector update driver) instance on a pmem namespace. - Ross noticed that the dax_device + dax_operations conversion broke __dax_zero_page_range(). The nvdimm unit tests fail to check this path, but xfstests immediately trips over it. No excuse for missing this before submitting the 4.12 pull request. These all pass the nvdimm unit tests and an xfstests spot check. The set has received a build success notification from the kbuild robot" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: filesystem-dax: fix broken __dax_zero_page_range() conversion libnvdimm, btt: ensure that initializing metadata clears poison libnvdimm: add an atomic vs process context flag to rw_bytes x86, pmem: Fix cache flushing for iovec write < 8 bytes device-dax: kill NR_DEV_DAX block, dax: move "select DAX" from BLOCK to FS_DAX device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX
2017-05-08block, dax: move "select DAX" from BLOCK to FS_DAXDan Williams
For configurations that do not enable DAX filesystems or drivers, do not require the DAX core to be built. Given that the 'direct_access' method has been removed from 'block_device_operations', we can also go ahead and remove the block-related dax helper functions from fs/block_dev.c to drivers/dax/super.c. This keeps dax details out of the block layer and lets the DAX core be built as a module in the FS_DAX=n case. Filesystems need to include dax.h to call bdev_dax_supported(). Cc: linux-xfs@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-05Merge tag 'libnvdimm-for-4.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has been in multiple -next releases. There were a few late breaking fixes and small features that got added in the last couple days, but the whole set has received a build success notification from the kbuild robot. Change summary: - Region media error reporting: A libnvdimm region device is the parent to one or more namespaces. To date, media errors have been reported via the "badblocks" attribute attached to pmem block devices for namespaces in "raw" or "memory" mode. Given that namespaces can be in "device-dax" or "btt-sector" mode this new interface reports media errors generically, i.e. independent of namespace modes or state. This subsequently allows userspace tooling to craft "ACPI 6.1 Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error" requests and submit them via the ioctl path for NVDIMM root bus devices. - Introduce 'struct dax_device' and 'struct dax_operations': Prompted by a request from Linus and feedback from Christoph this allows for dax capable drivers to publish their own custom dax operations. This fixes the broken assumption that all dax operations are related to a persistent memory device, and makes it easier for other architectures and platforms to add customized persistent memory support. - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is available for storage appliance applications to manually trigger memory controllers to drain write-pending buffers that would otherwise be flushed automatically by the platform ADR (asynchronous-DRAM-refresh) mechanism at a power loss event. Support for "locked" DIMMs is included to prevent namespaces from surfacing when the namespace label data area is locked. Finally, fixes for various reported deadlocks and crashes, also tagged for -stable. - ACPI / nfit driver updates: General updates of the nfit driver to add DSM command overrides, ACPI 6.1 health state flags support, DSM payload debug available by default, and various fixes. Acknowledgements that came after the branch was pushed: - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock": Tested-by: Yi Zhang <yizhan@redhat.com> - commit 23f498448362 "libnvdimm: rework region badblocks clearing" Tested-by: Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits) libnvdimm, pfn: fix 'npfns' vs section alignment libnvdimm: handle locked label storage areas libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED brd: fix uninitialized use of brd->dax_dev block, dax: use correct format string in bdev_dax_supported device-dax: fix sysfs attribute deadlock libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking" libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering libnvdimm: rework region badblocks clearing acpi, nfit: kill ACPI_NFIT_DEBUG libnvdimm: fix clear length of nvdimm_forget_poison() libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify libnvdimm, region: sysfs trigger for nvdimm_flush() libnvdimm: fix phys_addr for nvdimm_clear_poison x86, dax, pmem: remove indirection around memcpy_from_pmem() block: remove block_device_operations ->direct_access() block, dax: convert bdev_dax_supported() to dax_direct_access() filesystem-dax: convert to dax_direct_access() Revert "block: use DAX for partition table reads" ext2, ext4, xfs: retrieve dax_device for iomap operations ...
2017-04-20dax: introduce dax_direct_access()Dan Williams
Replace bdev_direct_access() with dax_direct_access() that uses dax_device and dax_operations instead of a block_device and block_device_operations for dax. Once all consumers of the old api have been converted bdev_direct_access() will be deleted. Given that block device partitioning decisions can cause dax page alignment constraints to be violated this also introduces the bdev_dax_pgoff() helper. It handles calculating a logical pgoff relative to the dax_device and also checks for page alignment. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-03-28blk-throttle: add configure option for new .low interfaceShaohua Li
As discussed in LSF, add configure option for the interface and mark it as experimental, so people can try/test. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull vhost updates from Michael Tsirkin: "virtio, vhost: optimizations, fixes Looks like a quiet cycle for vhost/virtio, just a couple of minor tweaks. Most notable is automatic interrupt affinity for blk and scsi. Hopefully other devices are not far behind" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio-console: avoid DMA from stack vhost: introduce O(1) vq metadata cache virtio_scsi: use virtio IRQ affinity virtio_blk: use virtio IRQ affinity blk-mq: provide a default queue mapping for virtio device virtio: provide a method to get the IRQ affinity mask for a virtqueue virtio: allow drivers to request IRQ affinity when creating VQs virtio_pci: simplify MSI-X setup virtio_pci: don't duplicate the msix_enable flag in struct pci_dev virtio_pci: use shared interrupts for virtqueues virtio_pci: remove struct virtio_pci_vq_info vhost: try avoiding avail index access when getting descriptor virtio_mmio: expose header to userspace