lwn.git/drivers/s390/cio, branch docs-6.9

Merge tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2024-01-11T02:18:20+00:00

Pull s390 updates from Alexander Gordeev: - Add machine variable capacity information to /proc/sysinfo. - Limit the waste of page tables and always align vmalloc area size and base address on segment boundary. - Fix a memory leak when an attempt to register interruption sub class (ISC) for the adjunct-processor (AP) guest failed. - Reset response code AP_RESPONSE_INVALID_GISA to understandable by guest AP_RESPONSE_INVALID_ADDRESS in response to a failed interruption sub class (ISC) registration attempt. - Improve reaction to adjunct-processor (AP) AP_RESPONSE_OTHERWISE_CHANGED response code when enabling interrupts on behalf of a guest. - Fix incorrect sysfs 'status' attribute of adjunct-processor (AP) queue device bound to the vfio_ap device driver when the mediated device is attached to a guest, but the queue device is not passed through. - Rework struct ap_card to hold the whole adjunct-processor (AP) card hardware information. As result, all the ugly bit checks are replaced by simple evaluations of the required bit fields. - Improve handling of some weird scenarios between service element (SE) host and SE guest with adjunct-processor (AP) pass-through support. - Change local_ctl_set_bit() and local_ctl_clear_bit() so they return the previous value of the to be changed control register. This is useful if a bit is only changed temporarily and the previous content needs to be restored. - The kernel starts with machine checks disabled and is expected to enable it once trap_init() is called. However the implementation allows machine checks early. Consistently enable it in trap_init() only. - local_mcck_disable() and local_mcck_enable() assume that machine checks are always enabled. Instead implement and use local_mcck_save() and local_mcck_restore() to disable machine checks and restore the previous state. - Modification of floating point control (FPC) register of a traced process using ptrace interface may lead to corruption of the FPC register of the tracing process. Fix this. - kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control (FPC) register in vCPU, but may lead to corruption of the FPC register of the host process. Fix this. - Use READ_ONCE() to read a vCPU floating point register value from the memory mapped area. This avoids that, depending on code generation, a different value is tested for validity than the one that is used. - Get rid of test_fp_ctl(), since it is quite subtle to use it correctly. Instead copy a new floating point control register value into its save area and test the validity of the new value when loading it. - Remove superfluous save_fpu_regs() call. - Remove s390 support for ARCH_WANTS_DYNAMIC_TASK_STRUCT. All machines provide the vector facility since many years and the need to make the task structure size dependent on the vector facility does not exist. - Remove the "novx" kernel command line option, as the vector code runs without any problems since many years. - Add the vector facility to the z13 architecture level set (ALS). All hypervisors support the vector facility since many years. This allows compile time optimizations of the kernel. - Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx(). As result, the compiled code will have less runtime checks and less code. - Convert pgste_get_lock() and pgste_set_unlock() ASM inlines to C. - Convert the struct subchannel spinlock from pointer to member. * tag 's390-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (24 commits) Revert "s390: update defconfigs" s390/cio: make sch->lock spinlock pointer a member s390: update defconfigs s390/mm: convert pgste locking functions to C s390/fpu: get rid of MACHINE_HAS_VX s390/als: add vector facility to z13 architecture level set s390/fpu: remove "novx" option s390/fpu: remove ARCH_WANTS_DYNAMIC_TASK_STRUCT support KVM: s390: remove superfluous save_fpu_regs() call s390/fpu: get rid of test_fp_ctl() KVM: s390: use READ_ONCE() to read fpc register value KVM: s390: fix setting of fpc register s390/ptrace: handle setting of fpc register correctly s390/nmi: implement and use local_mcck_save() / local_mcck_restore() s390/nmi: consistently enable machine checks in trap_init() s390/ctlreg: return old register contents when changing bits s390/ap: handle outband SE bind state change s390/ap: store TAPQ hwinfo in struct ap_card s390/vfio-ap: fix sysfs status attribute for AP queue devices s390/vfio-ap: improve reaction to response code 07 from PQAP(AQIC) command ...

s390/cio: make sch->lock spinlock pointer a member

2023-12-12T13:41:58+00:00

The lock member of struct subchannel used to be a spinlock, but became a pointer to a spinlock with commit 2ec2298412e1 ("[S390] subchannel lock conversion."). This might have been justified back then, but with the current state of affairs, there is no reason to manage a separate spinlock object. Let's simplify things and pull the spinlock back into struct subchannel. Signed-off-by: Halil Pasic Reviewed-by: Vineeth Vijayan Link: https://lore.kernel.org/r/20231101115751.2308307-1-pasic@linux.ibm.com Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev

eventfd: simplify eventfd_signal()

2023-11-28T13:08:38+00:00

Ever since the eventfd type was introduced back in 2007 in commit e1ad7468c77d ("signal/timer/event: eventfd core") the eventfd_signal() function only ever passed 1 as a value for @n. There's no point in keeping that additional argument. Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org Acked-by: Xu Yilun Acked-by: Andrew Donnellan # ocxl Acked-by: Eric Farman # s390 Reviewed-by: Jan Kara Reviewed-by: Jens Axboe Signed-off-by: Christian Brauner

Merge tag 's390-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2023-11-03T20:17:22+00:00

Pull s390 updates from Vasily Gorbik: - Get rid of private VM_FAULT flags - Add word-at-a-time implementation - Add DCACHE_WORD_ACCESS support - Cleanup control register handling - Disallow CPU hotplug of CPU 0 to simplify its handling complexity, following a similar restriction in x86 - Optimize pai crypto map allocation - Update the list of crypto express EP11 coprocessor operation modes - Fixes and improvements for secure guests AP pass-through - Several fixes to address incorrect page marking for address translation with the "cmma no-dat" feature, preventing potential incorrect guest TLB flushes - Fix early IPI handling - Several virtual vs physical address confusion fixes - Various small fixes and improvements all over the code * tag 's390-6.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (74 commits) s390/cio: replace deprecated strncpy with strscpy s390/sclp: replace deprecated strncpy with strtomem s390/cio: fix virtual vs physical address confusion s390/cio: export CMG value as decimal s390: delete the unused store_prefix() function s390/cmma: fix handling of swapper_pg_dir and invalid_pg_dir s390/cmma: fix detection of DAT pages s390/sclp: handle default case in sclp memory notifier s390/pai_crypto: remove per-cpu variable assignement in event initialization s390/pai: initialize event count once at initialization s390/pai_crypto: use PERF_ATTACH_TASK define for per task detection s390/mm: add missing arch_set_page_dat() call to gmap allocations s390/mm: add missing arch_set_page_dat() call to vmem_crst_alloc() s390/cmma: fix initial kernel address space page table walk s390/diag: add missing virt_to_phys() translation to diag224() s390/mm,fault: move VM_FAULT_ERROR handling to do_exception() s390/mm,fault: remove VM_FAULT_BADMAP and VM_FAULT_BADACCESS s390/mm,fault: remove VM_FAULT_SIGNAL s390/mm,fault: remove VM_FAULT_BADCONTEXT s390/mm,fault: simplify kfence fault handling ...

s390/cio: replace deprecated strncpy with strscpy

2023-10-25T13:08:30+00:00

strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We expect both `params` and `id` to be NUL-terminated based on their usage with format strings: format_node_data(iuparams, iunodeid, &lir->incident_node); format_node_data(auparams, aunodeid, &lir->attached_node); switch (lir->iq.class) { case LIR_IQ_CLASS_DEGRADED: pr_warn("Link degraded: RS=%02x RSID=%04x IC=%02x " "IUPARAMS=%s IUNODEID=%s AUPARAMS=%s AUNODEID=%s\n", sei_area->rs, sei_area->rsid, lir->ic, iuparams, iunodeid, auparams, aunodeid); NUL-padding is not required as both `params` and `id` have been memset to 0: memset(params, 0, PARAMS_LEN); memset(id, 0, NODEID_LEN); Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Note that there's no overread bugs in the current implementation as the string literal "n/a" has a size much smaller than PARAMS_LEN or NODEID_LEN. Nonetheless, let's favor strscpy(). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Vineeth Vijayan Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231023-strncpy-drivers-s390-cio-chsc-c-v1-1-8b76a7b83260@google.com Signed-off-by: Vasily Gorbik

s390/cio: fix virtual vs physical address confusion

2023-10-25T13:08:29+00:00

Fix virtual vs physical address confusion (which currently are the same). Reviewed-by: Vineeth Vijayan Signed-off-by: Peter Oberparleiter Signed-off-by: Vasily Gorbik

s390/cio: export CMG value as decimal

2023-10-25T13:08:29+00:00

Change format of the "cmg" sysfs attribute from hex to decimal to make it easier to consume. Note that this should not break any existing users since only values 2 and 3 are currently exported. Also the main user already assumes decimal notation [1]. [1] https://sourceforge.net/p/sblim/gather/ci/master/tree/plugin/metriczCH.c Reviewed-by: Vineeth Vijayan Signed-off-by: Peter Oberparleiter Signed-off-by: Vasily Gorbik

s390/cio: fix a memleak in css_alloc_subchannel

2023-10-16T11:03:05+00:00

When dma_set_coherent_mask() fails, sch->lock has not been freed, which is allocated in css_sch_create_locks(), leading to a memleak. Fixes: 4520a91a976e ("s390/cio: use dma helpers for setting masks") Signed-off-by: Dinghao Liu Message-Id: <20230921071412.13806-1-dinghao.liu@zju.edu.cn> Link: https://lore.kernel.org/linux-s390/bd38baa8-7b9d-4d89-9422-7e943d626d6e@linux.ibm.com/ Reviewed-by: Halil Pasic Reviewed-by: Peter Oberparleiter Signed-off-by: Vasily Gorbik

s390: use control register bit defines

2023-09-19T11:26:57+00:00

Use control register bit defines instead of plain numbers where possible. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ctlreg: add local and system prefix to some functions

2023-09-19T11:26:56+00:00

Add local and system prefix to some functions to clarify they change control register contents on either the local CPU or the on all CPUs. This results in the following API: Two defines which load and save multiple control registers. The defines correlate with the following C prototypes: void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high); void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high); Two functions which locally set or clear one bit for a specified control register: void local_ctl_set_bit(unsigned int cr, unsigned int bit); void local_ctl_clear_bit(unsigned int cr, unsigned int bit); Two functions which set or clear one bit for a specified control register on all CPUs: void system_ctl_set_bit(unsigned int cr, unsigned int bit); void system_ctl_clear_bit(unsigend int cr, unsigned int bit); Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik