- 08 Nov, 2017 2 commits
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Harald Freudenberger authored
The reworked version of the random device driver now calls the arch_get_random_* functions on a very high frequency. It does about 100.000 calls to arch_get_random_long for providing 10 MB via /dev/urandom. Each invocation was fetching entropy from the hardware random generator which has a rate limit of about 4 MB/s. As the trng invocation waits until enough entropy is gathered, the random device driver is slowed down dramatically. The s390 true random generator is not designed for such a high rate. The TRNG is more designed to be used together with the arch_get_random_seed_* functions. This is similar to the way how powerpc has implemented their arch random functionality. This patch removes the invocations of the s390 TRNG for arch_get_random_long() and arch_get_random_int() but leaving the invocations for arch_get_random_seed_long() and arch_get_random_seed_int(). So the s390 arch random implementation now contributes high quality entropy to the kernel random device for reseeding. Signed-off-by:
Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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Christian Borntraeger authored
As of today QEMU does not provide the AIS facility to its guest. This prevents Linux guests from using PCI devices as the ais facility is checked during init. As this is just a performance optimization, we can move the ais check into the code where we need it (calling the SIC instruction). This is used at initialization and on interrupt. Both places do not require any serialization, so we can simply skip the instruction. Since we will now get all interrupts, we can also avoid the 2nd scan. As we can have multiple interrupts in parallel we might trigger spurious irqs more often for the non-AIS case but the core code can handle that. Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by:
Pierre Morel <pmorel@linux.vnet.ibm.com> Reviewed-by:
Halil Pasic <pasic@linux.vnet.ibm.com> Acked-by:
Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by:
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- 03 Nov, 2017 2 commits
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Sebastian Ott authored
qdio maintains an array of struct indicator_t. put_indicator takes a pointer to a member of a struct indicator_t within that array, calculates the index, and uses the array and the index to get the struct indicator_t. Simply use the pointer directly. Although the pointer happens to point to the first member of that struct use the container_of macro. Signed-off-by:
Ursula Braun <ubraun@linux.vnet.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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Sebastian Ott authored
qdio uses atomic_read to find an unused indicator and atomic_set to flag it as used. This could lead to multiple users getting the same indicator. Use atomic_cmpxchg instead. Signed-off-by:
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- 02 Nov, 2017 2 commits
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Vasily Gorbik authored
__LC_MCESAD is currently 4528 /* offsetof(struct lowcore, mcesad) */ that would require long-displacement facility for lg, which we don't have on z900. Fixes: 3037a52f ("s390/nmi: do register validation as early as possible") Signed-off-by:
Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by:
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Luc Van Oostenryck authored
s390 is big-endian only but sparse assumes the same endianness as the building machine. This is problematic for code which expect __BYTE_ORDER__ being correctly predefined by the compiler which sparse can then pre-process differently from what gcc would, depending on the building machine endianness. Fix this by letting sparse know about the architecture endianness. Signed-off-by:
Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by:
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- 26 Oct, 2017 3 commits
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Martin Schwidefsky authored
The decompressor for bzImage prints two informational messages which are not really helpful. The decompression step is fast and if something bad happens an error message will be printed. Remove the noise. Signed-off-by: -
Elena Reshetova authored
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable urdev.ref_count is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by:
Kees Cook <keescook@chromium.org> Reviewed-by:
David Windsor <dwindsor@gmail.com> Reviewed-by:
Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by:
Elena Reshetova <elena.reshetova@intel.com> Signed-off-by:
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Hendrik Brueckner authored
Add the hardware counters that are available with z14. With z14, the number of problem-state counters is reduced. The initialization is updated respectively. Signed-off-by:
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by:
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- 23 Oct, 2017 3 commits
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Harald Freudenberger authored
This patch introduces a new ap_qact() function which exploits the PQAP(QACT) subfunction. QACT is a new interface to Query the Ap Compatilibity Type based on a given AP qid, type, mode and version. Based on this new function the AP bus scan code is slightly reworked to use this new interface for querying the compatible type for each new AP queue device detected. So new and unknown devices can get automatically mapped to a compatible type and handled without the need for toleration patches for every new hardware. The currently highest known hardware is CEX6S. With this patch a possible successor can get queried for a combatible type known by the device driver without the need for an toleration patch. Signed-off-by:
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Harald Freudenberger authored
With the CEX6 there is a new CPRB (subfunction AU) used to generate protected keys from secure keys. This new CPRB needs to have the special flag set in the queue message header struct which is introduced with this fix. Signed-off-by:
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Harald Freudenberger authored
This patch adds the full CEX6S card support to the zcrypt device driver. A CEX6A/C/P is detected and displayed as such, the card and queue device driver code is updated to recognize it and the relative weight values for CEX4, CEX5 and CEX6 have been updated. Signed-off-by:
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- 19 Oct, 2017 5 commits
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Martin Schwidefsky authored
The validation of the CPU registers in the machine check handler is currently split into two parts. The first part is done at the start of the low level mcck_int_handler function, this includes the CPU timer register and the general purpose registers. The second part is done a bit later in s390_do_machine_check for all the other registers, including the control registers, floating pointer control, vector or floating pointer registers, the access registers, the guarded storage registers, the TOD programmable registers and the clock comparator. This is working fine to far but in theory a future extensions could cause the C code to use registers that are not validated yet. A better approach is to validate all CPU registers in "safe" assembler code before any C function is called. Reviewed-by:
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Martin Schwidefsky authored
The machine check extended save area is needed to store the vector registers and the guarded storage control block when a CPU is interrupted by a machine check. Move the slab cache allocation of the full save area to nmi.c, for early boot use a static __initdata block. Reviewed-by:
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Martin Schwidefsky authored
The nmi.h header has some constant defines for control register bits. These definitions should really be located in ctl_reg.h. Move and rename the defines. Reviewed-by:
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Martin Schwidefsky authored
Add a decoding union for the bits in control registers 2 and use 'union ctlreg0' and 'union ctlreg2' in update_cr_regs to improve readability. Reviewed-by:
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Martin Schwidefsky authored
The smp_send_stop() function can be called from s390_handle_damage while DAT is off. This happens if a machine check indicates that kernel gprs or control registers can not be restored. The function smp_send_stop reenables DAT via __load_psw_mask. That should work for the case of lost kernel gprs and the system will do the expected stop of all CPUs. But if control registers are lost, in particular CR13 with the home space ASCE, interesting secondary crashes may occur. Make smp_emergency_stop callable from nmi.c and remove the cpumask argument. Replace the smp_send_stop call with smp_emergency_stop in the s390_handle_damage function. In addition add notrace and NOKPROBE_SYMBOL annotations for all functions required for the emergency shutdown. Reviewed-by:
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- 18 Oct, 2017 7 commits
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Martin Schwidefsky authored
The boot_vdso_data variable is related to the vdso code, the magic of the initial vdso area for the early boot and the replacement of it in vdso_init should all be put into vdso.c. Signed-off-by: -
Vasily Gorbik authored
Enable niai instruction in the spinlock code at run-time for machines on which facility 49 is available (zEC12 and newer). Signed-off-by:
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Vasily Gorbik authored
Implement CPU alternatives, which allows to optionally patch newer instructions at runtime, based on CPU facilities availability. A new kernel boot parameter "noaltinstr" disables patching. Current implementation is derived from x86 alternatives. Although ideal instructions padding (when altinstr is longer then oldinstr) is added at compile time, and no oldinstr nops optimization has to be done at runtime. Also couple of compile time sanity checks are done: 1. oldinstr and altinstr must be <= 254 bytes long, 2. oldinstr and altinstr must not have an odd length. alternative(oldinstr, altinstr, facility); alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2); Both compile time and runtime padding consists of either 6/4/2 bytes nop or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes. .altinstructions and .altinstr_replacement sections are part of __init_begin : __init_end region and are freed after initialization. Signed-off-by:
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Sebastian Ott authored
Get rid of unused wrapper macros around debug_sprintf_exception. Signed-off-by:
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Sebastian Ott authored
debug_event_common memsets the active debug entry with zeros to prevent stale data leakage. This is overwritten with the actual debug data in the next step. Only write zeros to that part of the debug entry that's not used by new debug data. Micro benchmarks show a 2-10% reduction of cpu cycles with this approach. Signed-off-by:
Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by:
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Sebastian Ott authored
debug_event currently truncates the data if used with a size larger than the buf_size of the debug feature. For lots of callers of this function, wrappers have been implemented that loop until all data is handled. Move that functionality into debug_event_common and get rid of the wrappers. Signed-off-by:
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Philipp Rudo authored
Before kexec boots to a crash kernel it checks whether the image in memory changed after load. This is done by the function kdump_csum_valid, which returns true, i.e. an int != 0, on success and 0 otherwise. In other words when kdump_csum_valid returns an error code it means that the validation succeeded. This is not only counterintuitive but also produces the wrong result if the kernel was build without CONFIG_CRASH_DUMP. Fix this by making kdump_csum_valid return a bool. Signed-off-by:
Philipp Rudo <prudo@linux.vnet.ibm.com> Acked-by:
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- 16 Oct, 2017 6 commits
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Martin Schwidefsky authored
Merge tag 'vfio-ccw-20171016' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features Pull vfio-ccw update from Cornelia Huck: "Some improvements in data handling for vfio-ccw."
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Dong Jia Shi authored
If the count field of a ccw is zero, there is no need to try to pin page(s) for it. Let's check the count value before starting pinning operations. Reviewed-by:
Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> Message-Id: <20171011023822.42948-3-bjsdjshi@linux.vnet.ibm.com> Signed-off-by:
Cornelia Huck <cohuck@redhat.com>
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Dong Jia Shi authored
We currently return the same error code (-EFAULT) to indicate two different error cases: 1. a bug in vfio-ccw implementation has been found. 2. a buggy channel program has been detected. This brings difficulty for userland program (specifically Qemu) to handle. Let's use -EFAULT to only indicate the first case. For the second case, we simply hand over the ccws to lower level for further handling. Notice: Once a bad idaw address is detected, the current behavior is to suppress the ssch. With this fix, the channel program will be accepted, and part of the channel program (the part ahead of the bad idaw) could possibly be executed by the device before I/O conclusion. Suggested-by:
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Martin Schwidefsky authored
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Heiko Carstens authored
The debug feature code hasn't been touched in ages and the code also looks like this. Therefore clean up the code so it looks a bit more like current coding style. There is no functional change - actually I made also sure that the generated code with performance_defconfig is identical. A diff of old vs new with "objdump -d" is empty. The code is still not checkpatch clean, but that was not the goal. Signed-off-by:
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Vasyl Gomonovych authored
drivers/s390/crypto/pkey_api.c:128:11-18: WARNING: kzalloc should be used for cprbmem, instead of kmalloc/memset Use kzalloc rather than kmalloc followed by memset with 0 Signed-off-by:
Vasyl Gomonovych <gomonovych@gmail.com> Signed-off-by:
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- 12 Oct, 2017 1 commit
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Heiko Carstens authored
For an unknown reason the s390 kprobes instruction replacement function modifies the kprobe_status of the current CPU to KPROBE_SWAP_INST. This was supposed to catch traps that happened during instruction patching. Such a fault is not supposed to happen, and silently discarding such a fault is certainly also not what we want. In fact s390 is the only architecture which has this odd piece of code. Just remove this and behave like all other architectures. This was pointed out by Jens Remus. Reported-by:
Jens Remus <jremus@linux.vnet.ibm.com> Signed-off-by:
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- 09 Oct, 2017 8 commits
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Heiko Carstens authored
Just some trivial changes like removing the extern keyword from the header file, renaming arguments to match the man pages, and whitespace removal. Signed-off-by:
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Heiko Carstens authored
Like for the memset16/32/64 variants avoid that subsequent mvc instructions depend on each other since that might have negative performance impacts. This patch is currently hardly relevant since at least gcc 7.1 generates only inline memset code and not a single memset call. However there is no reason to not provide an optimized version just in case gcc generates memset calls again, like it did in the past. Signed-off-by:
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Heiko Carstens authored
Use memset64 instead of the (now) open-coded variant clear_table. Performance wise there is no difference. Signed-off-by:
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Heiko Carstens authored
Provide fast versions of the new memset variants. E.g. the generic memset64 is ten times slower than the optimized version if used on a whole page. Signed-off-by:
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Martin Schwidefsky authored
Add the store-hypervisor-information code into features using a tip branch for parallel merging into the KVM tree.
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QingFeng Hao authored
Add a syscall of s390_sthyi to implement STHYI instruction in LPAR which reuses the implementation for KVM by Janosch Frank - commit 95ca2cb5 ("KVM: s390: Add sthyi emulation"). STHYI(Store Hypervisor Information) is an emulated z/VM instruction that provides a guest with basic information about the layers it is running on. This includes information about the cpu configuration of both the machine and the lpar, as well as their names, machine model and machine type. This information enables an application to determine the maximum capacity of CPs and IFLs available to software. For the arguments of s390_sthyi, code shall be 0 and flags is reserved for future use, info is the output argument to store the required hypervisor info. Signed-off-by:
QingFeng Hao <haoqf@linux.vnet.ibm.com> Signed-off-by:
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QingFeng Hao authored
STHYI requires extensive locking in the higher hypervisors and is very computational/memory expensive. Therefore we cache the retrieved hypervisor info whose valid period is 1s with mutex to allow concurrent access. rw semaphore can't benefit here due to cache line bounce. Signed-off-by:
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QingFeng Hao authored
As we need to support sthyi instruction on LPAR too, move the common code to kernel part and kvm related code to intercept.c for better reuse. Signed-off-by:
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- 04 Oct, 2017 1 commit
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Heiko Carstens authored
We never optimized our rwsem inline assemblies to make use of the new atomic instructions. The generic rwsem implementation implicitly makes use of the new instructions, since it implements the required rwsem primitives with atomic operations, which we did optimize. However even when compiling for old architectures the generic variant still generates better code. So it's time to simply remove our old code and switch to the generic implementation. Signed-off-by:
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