summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2019-04-29s390/kernel: add support for kernel address space layout randomization (KASLR)Gerald Schaefer
This patch adds support for relocating the kernel to a random address. The random kernel offset is obtained from cpacf, using either TRNG, PRNO, or KMC_PRNG, depending on supported MSA level. KERNELOFFSET is added to vmcoreinfo, for crash --kaslr support. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: introduce .dma sectionsGerald Schaefer
With a relocatable kernel that could reside at any place in memory, code and data that has to stay below 2 GB needs special handling. This patch introduces .dma sections for such text, data and ex_table. The sections will be part of the decompressor kernel, so they will not be relocated and stay below 2 GB. Their location is passed over to the decompressed / relocated kernel via the .boot.preserved.data section. The duald and aste for control register setup also need to stay below 2 GB, so move the setup code from arch/s390/kernel/head64.S to arch/s390/boot/head.S. The duct and linkage_stack could reside above 2 GB, but their content has to be preserved for the decompresed kernel, so they are also moved into the .dma section. The start and end address of the .dma sections is added to vmcoreinfo, for crash support, to help debugging in case the kernel crashed there. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/sclp: do not use static sccbsGerald Schaefer
The sccbs for init/read/sdias/early have to be located below 2 GB, and they are currently defined as a static buffer. With a relocatable kernel that could reside at any place in memory, this will no longer guarantee the location below 2 GB, so use a dynamic GFP_DMA allocation instead. The sclp_early_sccb buffer needs special handling, as it can be used very early, and by both the decompressor and also the decompressed kernel. Therefore, a fixed 4 KB buffer is introduced at 0x11000, the former PARMAREA_END. The new PARMAREA_END is now 0x12000, and it is renamed to HEAD_END, as it is rather the end of head.S and not the end of the parmarea. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kprobes: use static buffer for insn_pageGerald Schaefer
With a relocatable kernel that could reside at any place in memory, the current logic for allocating a kprobes insn_page does not work. The GFP_DMA allocated buffer might be more than 2 GB away from the kernel. Use a static buffer for the insn_page instead. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: convert SYSCALL and PGM_CHECK handlers to .quadGerald Schaefer
With a relocatable kernel that could reside at any place in memory, the storage size for the SYSCALL and PGM_CHECK handlers needs to be increased from .long to .quad. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kernel: build a relocatable kernelGerald Schaefer
This patch adds support for building a relocatable kernel with -fPIE. The kernel will be relocated to 0 early in the boot process. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390: enable processes for mio instructionsSebastian Ott
Allow for userspace to use PCI MIO instructions. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: add parameter to disable usage of MIO instructionsSebastian Ott
Allow users to disable usage of MIO instructions by specifying pci=nomio at the kernel command line. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: provide support for MIO instructionsSebastian Ott
Provide support for PCI I/O instructions that work on mapped IO addresses. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/ism: move oddities of device IO to wrapper functionSebastian Ott
ISM devices are special in how they access PCI memory space. Provide wrappers for handling commands to the device. No functional change. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: move io address mapping code to pci_insn.cSebastian Ott
This is a preparation patch for usage of new pci instructions. No functional change. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: add parameter to force floating irqsSebastian Ott
Provide a kernel parameter to force the usage of floating interrupts. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: gather statistics for floating vs directed irqsSebastian Ott
Gather statistics to distinguish floating and directed interrupts. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390: show statistics for MSI IRQsSebastian Ott
Improve /proc/interrupts on s390 to show statistics for individual MSI interrupts. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: provide support for CPU directed interruptsSebastian Ott
Up until now all interrupts on s390 have been floating. For MSI interrupts we've used a global summary bit vector (with a bit for each function) and a per-function interrupt bit vector (with a bit per MSI). This patch introduces a new IRQ delivery mode: CPU directed interrupts. In this new mode a per-CPU interrupt bit vector is used (with a bit per MSI per function). Further it is now possible to direct an IRQ to a specific CPU so we can finally support IRQ affinity. If an interrupt can't be delivered because the appointed CPU is occupied by a hypervisor the interrupt is delivered floating. For this a global summary bit vector is used (with a bit per CPU). Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/airq: provide cacheline aligned ivsSebastian Ott
Provide the ability to create cachesize aligned interrupt vectors. These will be used for per-CPU interrupt vectors. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: clarify interrupt vector usageSebastian Ott
Rename and clarify the usage of the interrupt bit vectors. Also change the array of the per-function bit vectors to be dynamically allocated. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/airq: recognize directed interruptsSebastian Ott
Add an extra parameter for airq handlers to recognize floating vs. directed interrupts. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/sclp: detect DIRQ facilitySebastian Ott
Detect the adapter CPU directed interruption facility. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: move everything irq related to pci_irq.cSebastian Ott
Move everything interrupt related from pci.c to pci_irq.c. No functional change. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: remove unused defineSebastian Ott
No users of pr_debug in that file. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/pci: mark command line parser data __initdataSebastian Ott
No point to keep that around. Signed-off-by: Sebastian Ott <sebott@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/ipl: Provide has_secure sysfs attributePhilipp Rudo
Provide an interface for userspace so it can find out if a machine is capeable of doing secure boot. The interface is, for example, needed for zipl so it can find out which file format it can/should write to disk. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Disable kexec_load when IPLed securePhilipp Rudo
A kernel loaded via kexec_load cannot be verified. Thus disable kexec_load systemcall in kernels which where IPLed securely. Use the IMA mechanism to do so. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Create ipl report and pass to next kernelPhilipp Rudo
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Signature verification prototypePhilipp Rudo
Add kernel signature verification to kexec_file. The verification is based on module signature verification and works with kernel images signed via scripts/sign-file. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Load new kernel to absolute 0Philipp Rudo
The leading 64 kB of a kernel image doesn't contain any data needed to boot the new kernel when it was loaded via kexec_file. Thus kexec_file currently strips them off before loading the image. Keep the leading 64 kB in order to be able to pass a ipl_report to the next kernel. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Unify loader codePhilipp Rudo
s390_image_load and s390_elf_load have the same code to load the different components. Combine this functionality in one shared function. While at it move kexec_file_update_kernel into the new function as well. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Simplify parmarea accessPhilipp Rudo
Access the parmarea in head.S via a struct instead of individual offsets. While at it make the fields in the parmarea .quads. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/purgatory: Omit use of bin2cPhilipp Rudo
Omit use of script/bin2c hack. Directly include into assembler file instead. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/purgatory: Reduce purgatory sizePhilipp Rudo
The purgatory is compiled into the vmlinux and keept in memory all the time during runtime. Thus any section not needed to load the purgatory unnecessarily bloats up its foot print in file- and memorysize. Reduce the purgatory size by stripping the unneeded sections from the purgatory. This reduces the purgatories size by ~33%. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Fix detection of text segment in ELF loaderPhilipp Rudo
To register data for the next kernel (command line, oldmem_base, etc.) the current kernel needs to find the ELF segment that contains head.S. This is currently done by checking ifor 'phdr->p_paddr == 0'. This works fine for the current kernel build but in theory the first few pages could be skipped. Make the detection more robust by checking if the entry point lies within the segment. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-29s390/kexec_file: Fix potential segment overlap in ELF loaderPhilipp Rudo
When loading an ELF image via kexec_file the segment alignment is ignored in the calculation for the load address of the next segment. When there are multiple segments this can lead to segment overlap and thus load failure. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Fixes: 8be018827154 ("s390/kexec_file: Add ELF loader") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/zcore: Rename ipl_block to mitigate name collisionPhilipp Rudo
With git commit 1e941d39493f1820475d80729a03cd7ab8c3c86d "s390: move ipl block to .boot.preserved.data section" the earl_ipl_block got renamed to ipl_block and became publicly available via boot_data.h. This might cause problems with zcore, which has it's own ipl_block variable. Thus rename the ipl_block in zcore to prevent name collision and highlight that it's only used locally. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Fixes: 1e941d39493f ("s390: move ipl block to .boot.preserved.data section") Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/boot: pad bzImage to 4KMartin Schwidefsky
In order to be able to sign the bzImage independent of the block size of the IPL device, align the bzImage to 4096 bytes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/ipl: add helper functions to create an IPL reportMartin Schwidefsky
PR: Adjusted to the use in kexec_file later. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/ipl: read IPL report at early bootMartin Schwidefsky
Read the IPL Report block provided by secure-boot, add the entries of the certificate list to the system key ring and print the list of components. PR: Adjust to Vasilys bootdata_preserved patch set. Preserve ipl_cert_list for later use in kexec_file. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/ipl: add definitions for the IPL report blockMartin Schwidefsky
To transport the information required for secure boot a new IPL report will be created at boot time. It will be written to memory right after the IPL parameter block. To work with the IPL report a couple of additional structure definitions are added the the uapi/ipl.h header. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/ipl: provide uapi header for list directed IPLMartin Schwidefsky
The IPL parameter block is used as an interface between Linux and the machine to query and change the boot device and boot options. To be able to create IPL parameter block in user space and pass it as segment to kexec provide an uapi header with proper structure definitions for the block. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-26s390/ipl: make ipl_info less confusingMartin Schwidefsky
The ipl_info union in struct ipl_parameter_block has the same name as the struct ipl_info. This does not help while reading the code and the union in struct ipl_parameter_block does not need to be named. Drop the name from the union. Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25s390: report new CPU capabilitiesMartin Schwidefsky
Add hardware capability bits and features tags to /proc/cpuinfo for 4 new CPU features: "Vector-Enhancements Facility 2" (tag "vxe2", hwcap 2^15) "Vector-Packed-Decimal-Enhancement Facility" (tag "vxp", hwcap 2^16) "Enhanced-Sort Facility" (tag "sort", hwcap 2^17) "Deflate-Conversion Facility" (tag "dflt", hwcap 2^18) Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25s390/crypto: use TRNG for seeding/reseedingHarald Freudenberger
With the z14 machine there came also a CPACF hardware extension which provides a True Random Number Generator. This TRNG can be accessed with a new subfunction code within the CPACF prno instruction and provides random data with very high entropy. So if there is a TRNG available, let's use it for initial seeding and reseeding instead of the current implementation which tries to generate entropy based on stckf (store clock fast) jitters. For details about the amount of data needed and pulled for seeding and reseeding there can be explaining comments in the code found. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25s390/crypto: rework generate_entropy function for pseudo random ddHarald Freudenberger
Here is a rework of the generate_entropy function of the pseudo random device driver exploiting the prno CPACF instruction. George Spelvin pointed out some issues with the existing implementation. One point was, that the buffer used to store the stckf values is 2 pages which are initially filled with get_random_bytes() for each 64 byte junk produced by the function. Another point was that the stckf values only carry entropy in the LSB and thus a buffer of 2 pages is not really needed. Then there was a comment about the use of the kimd cpacf function without proper initialization. The rework addresses these points and now one page is used and only one half of this is filled with get_random_bytes() on each chunk of 64 bytes requested data. The other half of the page is filled with stckf values exored into with an overlap of 4 bytes. This can be done due to the fact that only the lower 4 bytes carry entropy we need. For more details about the algorithm used, see the header of the function. The generate_entropy() function now uses the cpacf function klmd with proper initialization of the parameter block to perform the sha512 hash. George also pointed out some issues with the internal buffers used for seeding and reads. These buffers are now zeroed with memzero_implicit after use. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reported-by: George Spelvin <lkml@sdf.org> Suggested-by: George Spelvin <lkml@sdf.org> Reviewed-by: Patrick Steuer <steuer@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-25Merge tag 'vfio-ccw-20190425' of ↵Martin Schwidefsky
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features Pull vfio-ccw from Cornelia Huck with the following changes: - support for sending halt/clear requests to the device - various bug fixes
2019-04-24vfio-ccw: Prevent quiesce function going into an infinite loopFarhan Ali
The quiesce function calls cio_cancel_halt_clear() and if we get an -EBUSY we go into a loop where we: - wait for any interrupts - flush all I/O in the workqueue - retry cio_cancel_halt_clear During the period where we are waiting for interrupts or flushing all I/O, the channel subsystem could have completed a halt/clear action and turned off the corresponding activity control bits in the subchannel status word. This means the next time we call cio_cancel_halt_clear(), we will again start by calling cancel subchannel and so we can be stuck between calling cancel and halt forever. Rather than calling cio_cancel_halt_clear() immediately after waiting, let's try to disable the subchannel. If we succeed in disabling the subchannel then we know nothing else can happen with the device. Suggested-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Message-Id: <4d5a4b98ab1b41ac6131b5c36de18b76c5d66898.1555449329.git.alifm@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Acked-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: Release any channel program when releasing/removing vfio-ccw mdevFarhan Ali
When releasing the vfio-ccw mdev, we currently do not release any existing channel program and its pinned pages. This can lead to the following warning: [1038876.561565] WARNING: CPU: 2 PID: 144727 at drivers/vfio/vfio_iommu_type1.c:1494 vfio_sanity_check_pfn_list+0x40/0x70 [vfio_iommu_type1] .... 1038876.561921] Call Trace: [1038876.561935] ([<00000009897fb870>] 0x9897fb870) [1038876.561949] [<000003ff8013bf62>] vfio_iommu_type1_detach_group+0xda/0x2f0 [vfio_iommu_type1] [1038876.561965] [<000003ff8007b634>] __vfio_group_unset_container+0x64/0x190 [vfio] [1038876.561978] [<000003ff8007b87e>] vfio_group_put_external_user+0x26/0x38 [vfio] [1038876.562024] [<000003ff806fc608>] kvm_vfio_group_put_external_user+0x40/0x60 [kvm] [1038876.562045] [<000003ff806fcb9e>] kvm_vfio_destroy+0x5e/0xd0 [kvm] [1038876.562065] [<000003ff806f63fc>] kvm_put_kvm+0x2a4/0x3d0 [kvm] [1038876.562083] [<000003ff806f655e>] kvm_vm_release+0x36/0x48 [kvm] [1038876.562098] [<00000000003c2dc4>] __fput+0x144/0x228 [1038876.562113] [<000000000016ee82>] task_work_run+0x8a/0xd8 [1038876.562125] [<000000000014c7a8>] do_exit+0x5d8/0xd90 [1038876.562140] [<000000000014d084>] do_group_exit+0xc4/0xc8 [1038876.562155] [<000000000015c046>] get_signal+0x9ae/0xa68 [1038876.562169] [<0000000000108d66>] do_signal+0x66/0x768 [1038876.562185] [<0000000000b9e37e>] system_call+0x1ea/0x2d8 [1038876.562195] 2 locks held by qemu-system-s39/144727: [1038876.562205] #0: 00000000537abaf9 (&container->group_lock){++++}, at: __vfio_group_unset_container+0x3c/0x190 [vfio] [1038876.562230] #1: 00000000670008b5 (&iommu->lock){+.+.}, at: vfio_iommu_type1_detach_group+0x36/0x2f0 [vfio_iommu_type1] [1038876.562250] Last Breaking-Event-Address: [1038876.562262] [<000003ff8013aa24>] vfio_sanity_check_pfn_list+0x3c/0x70 [vfio_iommu_type1] [1038876.562272] irq event stamp: 4236481 [1038876.562287] hardirqs last enabled at (4236489): [<00000000001cee7a>] console_unlock+0x6d2/0x740 [1038876.562299] hardirqs last disabled at (4236496): [<00000000001ce87e>] console_unlock+0xd6/0x740 [1038876.562311] softirqs last enabled at (4234162): [<0000000000b9fa1e>] __do_softirq+0x556/0x598 [1038876.562325] softirqs last disabled at (4234153): [<000000000014e4cc>] irq_exit+0xac/0x108 [1038876.562337] ---[ end trace 6c96d467b1c3ca06 ]--- Similarly we do not free the channel program when we are removing the vfio-ccw device. Let's fix this by resetting the device and freeing the channel program and pinned pages in the release path. For the remove path we can just quiesce the device, since in the remove path the mediated device is going away for good and so we don't need to do a full reset. Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Message-Id: <ae9f20dc8873f2027f7b3c5d2aaa0bdfe06850b8.1554756534.git.alifm@linux.ibm.com> Acked-by: Eric Farman <farman@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: Do not call flush_workqueue while holding the spinlockFarhan Ali
Currently we call flush_workqueue while holding the subchannel spinlock. But flush_workqueue function can go to sleep, so do not call the function while holding the spinlock. Fixes the following bug: [ 285.203430] BUG: scheduling while atomic: bash/14193/0x00000002 [ 285.203434] INFO: lockdep is turned off. .... [ 285.203485] Preemption disabled at: [ 285.203488] [<000003ff80243e5c>] vfio_ccw_sch_quiesce+0xbc/0x120 [vfio_ccw] [ 285.203496] CPU: 7 PID: 14193 Comm: bash Tainted: G W .... [ 285.203504] Call Trace: [ 285.203510] ([<0000000000113772>] show_stack+0x82/0xd0) [ 285.203514] [<0000000000b7a102>] dump_stack+0x92/0xd0 [ 285.203518] [<000000000017b8be>] __schedule_bug+0xde/0xf8 [ 285.203524] [<0000000000b95b5a>] __schedule+0x7a/0xc38 [ 285.203528] [<0000000000b9678a>] schedule+0x72/0xb0 [ 285.203533] [<0000000000b9bfbc>] schedule_timeout+0x34/0x528 [ 285.203538] [<0000000000b97608>] wait_for_common+0x118/0x1b0 [ 285.203544] [<0000000000166d6a>] flush_workqueue+0x182/0x548 [ 285.203550] [<000003ff80243e6e>] vfio_ccw_sch_quiesce+0xce/0x120 [vfio_ccw] [ 285.203556] [<000003ff80245278>] vfio_ccw_mdev_reset+0x38/0x70 [vfio_ccw] [ 285.203562] [<000003ff802458b0>] vfio_ccw_mdev_remove+0x40/0x78 [vfio_ccw] [ 285.203567] [<000003ff801a499c>] mdev_device_remove_ops+0x3c/0x80 [mdev] [ 285.203573] [<000003ff801a4d5c>] mdev_device_remove+0xc4/0x130 [mdev] [ 285.203578] [<000003ff801a5074>] remove_store+0x6c/0xa8 [mdev] [ 285.203582] [<000000000046f494>] kernfs_fop_write+0x14c/0x1f8 [ 285.203588] [<00000000003c1530>] __vfs_write+0x38/0x1a8 [ 285.203593] [<00000000003c187c>] vfs_write+0xb4/0x198 [ 285.203597] [<00000000003c1af2>] ksys_write+0x5a/0xb0 [ 285.203601] [<0000000000b9e270>] system_call+0xdc/0x2d8 Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Message-Id: <626bab8bb2958ae132452e1ddaf1b20882ad5a9d.1554756534.git.alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: add handling for async channel instructionsCornelia Huck
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>
2019-04-24s390/cio: export hsch to modulesCornelia Huck
The vfio-ccw code will need this, and it matches treatment of ssch and csch. Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24vfio-ccw: add capabilities chainCornelia Huck
Allow to extend the regions used by vfio-ccw. The first user will be handling of halt and clear subchannel. Reviewed-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Cornelia Huck <cohuck@redhat.com>