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2019-10-17vfio-ccw: Rework the io_fctl traceEric Farman1-2/+2
Using __field_struct for the schib is convenient, but it doesn't appear to let us filter based on any of the schib elements. Specifying the full schid or any element within it results in various errors by the parser. So, expand that out to its component elements, so we can limit the trace to a single device. While we are at it, rename this trace to the function name, so we remember what is being traced instead of an abstract reference to the function control bit of the SCSW. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20191016142040.14132-5-farman@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-10-17vfio-ccw: Add a trace for asynchronous requestsEric Farman1-0/+4
Since the asynchronous requests are typically associated with error recovery, let's add a simple trace when one of those is issued to a device. Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20191016142040.14132-4-farman@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-10-17vfio-ccw: Refactor how the traces are builtEric Farman1-3/+0
Commit 3cd90214b70f ("vfio: ccw: add tracepoints for interesting error paths") added a quick trace point to determine where a channel program failed while being processed. It's a great addition, but adding more traces to vfio-ccw is more cumbersome than it needs to be. Let's refactor how this is done, so that additional traces are easier to add and can exist outside of the FSM if we ever desire. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20191016142040.14132-2-farman@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-08-23vfio-ccw: add some loggingCornelia Huck1-1/+50
Usually, the common I/O layer logs various things into the s390 cio debug feature, which has been very helpful in the past when looking at crash dumps. As vfio-ccw devices unbind from the standard I/O subchannel driver, we lose some information there. Let's introduce some vfio-ccw debug features and log some things there. (Unfortunately we cannot reuse the cio debug feature from a module.) Message-Id: <20190816151505.9853-2-cohuck@redhat.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: add handling for async channel instructionsCornelia Huck1-2/+117
Add a region to the vfio-ccw device that can be used to submit asynchronous I/O instructions. ssch continues to be handled by the existing I/O region; the new region handles hsch and csch. Interrupt status continues to be reported through the same channels as for ssch. Acked-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: rework ssch state handlingCornelia Huck1-5/+14
The flow for processing ssch requests can be improved by splitting the BUSY state: - CP_PROCESSING: We reject any user space requests while we are in the process of translating a channel program and submitting it to the hardware. Use -EAGAIN to signal user space that it should retry the request. - CP_PENDING: We have successfully submitted a request with ssch and are now expecting an interrupt. As we can't handle more than one channel program being processed, reject any further requests with -EBUSY. A final interrupt will move us out of this state. By making this a separate state, we make it possible to issue a halt or a clear while we're still waiting for the final interrupt for the ssch (in a follow-on patch). It also makes a lot of sense not to preemptively filter out writes to the io_region if we're in an incorrect state: the state machine will handle this correctly. Reviewed-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: make it safe to access channel programsCornelia Huck1-0/+5
When we get a solicited interrupt, the start function may have been cleared by a csch, but we still have a channel program structure allocated. Make it safe to call the cp accessors in any case, so we can call them unconditionally. While at it, also make sure that functions called from other parts of the code return gracefully if the channel program structure has not been initialized (even though that is a bug in the caller). Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2018-12-12vfio: ccw: Merge BUSY and BOXED statesPierre Morel1-6/+1
VFIO_CCW_STATE_BOXED and VFIO_CCW_STATE_BUSY have identical actions for the same events. Let's merge both into a single state to simplify the code. We choose to keep VFIO_CCW_STATE_BUSY. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Message-Id: <1539767923-10539-2-git-send-email-pmorel@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2018-09-27s390/cio: Convert ccw_io_region to pointerEric Farman1-3/+3
In the event that we want to change the layout of the ccw_io_region in the future[1], it might be easier to work with it as a pointer within the vfio_ccw_private struct rather than an embedded struct. [1] https://patchwork.kernel.org/comment/22228541/ Signed-off-by: Eric Farman <farman@linux.ibm.com> Message-Id: <20180921204013.95804-2-farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2018-05-29vfio: ccw: add tracepoints for interesting error pathsHalil Pasic1-1/+16
Add some tracepoints so we can inspect what is not working as is should. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Dong Jia Shi <bjsdjshi@linux.ibm.com> Message-Id: <20180523025645.8978-5-bjsdjshi@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2018-04-23vfio: ccw: process ssch with interrupts disabledCornelia Huck1-7/+12
When we call ssch, an interrupt might already be pending once we return from the START SUBCHANNEL instruction. Therefore we need to make sure interrupts are disabled while holding the subchannel lock until after we're done with our processing. Cc: stable@vger.kernel.org #v4.12+ Reviewed-by: Dong Jia Shi <bjsdjshi@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com> Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-01vfio-ccw: fence off transport modeCornelia Huck1-0/+5
vfio-ccw only supports command mode for channel programs, not transport mode. User space is supposed to already take care of that and pass us command-mode ORBs only, but better make sure and return an error to the caller instead of trying to process tcws as ccws. Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Acked-by: Halil Pasic <pasic@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
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>
2017-04-12vfio: ccw: remove unnecessary NULL checks of a pointerDong Jia Shi1-5/+1
Remove several unnecessary checks for the @private pointer, since it can never be NULL in these places. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Message-Id: <20170412090816.79108-2-bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-03-31vfio: ccw: introduce a finite state machineDong Jia Shi1-0/+207
The current implementation doesn't check if the subchannel is in a proper device state when handling an event. Let's introduce a finite state machine to manage the state/event change. Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Message-Id: <20170317031743.40128-14-bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>