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2025-12-05Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - Support for userspace handling of synchronous external aborts (SEAs), allowing the VMM to potentially handle the abort in a non-fatal manner - Large rework of the VGIC's list register handling with the goal of supporting more active/pending IRQs than available list registers in hardware. In addition, the VGIC now supports EOImode==1 style deactivations for IRQs which may occur on a separate vCPU than the one that acked the IRQ - Support for FEAT_XNX (user / privileged execute permissions) and FEAT_HAF (hardware update to the Access Flag) in the software page table walkers and shadow MMU - Allow page table destruction to reschedule, fixing long need_resched latencies observed when destroying a large VM - Minor fixes to KVM and selftests Loongarch: - Get VM PMU capability from HW GCFG register - Add AVEC basic support - Use 64-bit register definition for EIOINTC - Add KVM timer test cases for tools/selftests RISC/V: - SBI message passing (MPXY) support for KVM guest - Give a new, more specific error subcode for the case when in-kernel AIA virtualization fails to allocate IMSIC VS-file - Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually in small chunks - Fix guest page fault within HLV* instructions - Flush VS-stage TLB after VCPU migration for Andes cores s390: - Always allocate ESCA (Extended System Control Area), instead of starting with the basic SCA and converting to ESCA with the addition of the 65th vCPU. The price is increased number of exits (and worse performance) on z10 and earlier processor; ESCA was introduced by z114/z196 in 2010 - VIRT_XFER_TO_GUEST_WORK support - Operation exception forwarding support - Cleanups x86: - Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO SPTE caching is disabled, as there can't be any relevant SPTEs to zap - Relocate a misplaced export - Fix an async #PF bug where KVM would clear the completion queue when the guest transitioned in and out of paging mode, e.g. when handling an SMI and then returning to paged mode via RSM - Leave KVM's user-return notifier registered even when disabling virtualization, as long as kvm.ko is loaded. On reboot/shutdown, keeping the notifier registered is ok; the kernel does not use the MSRs and the callback will run cleanly and restore host MSRs if the CPU manages to return to userspace before the system goes down - Use the checked version of {get,put}_user() - Fix a long-lurking bug where KVM's lack of catch-up logic for periodic APIC timers can result in a hard lockup in the host - Revert the periodic kvmclock sync logic now that KVM doesn't use a clocksource that's subject to NTP corrections - Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the latter behind CONFIG_CPU_MITIGATIONS - Context switch XCR0, XSS, and PKRU outside of the entry/exit fast path; the only reason they were handled in the fast path was to paper of a bug in the core #MC code, and that has long since been fixed - Add emulator support for AVX MOV instructions, to play nice with emulated devices whose guest drivers like to access PCI BARs with large multi-byte instructions x86 (AMD): - Fix a few missing "VMCB dirty" bugs - Fix the worst of KVM's lack of EFER.LMSLE emulation - Add AVIC support for addressing 4k vCPUs in x2AVIC mode - Fix incorrect handling of selective CR0 writes when checking intercepts during emulation of L2 instructions - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32] on VMRUN and #VMEXIT - Fix a bug where KVM corrupt the guest code stream when re-injecting a soft interrupt if the guest patched the underlying code after the VM-Exit, e.g. when Linux patches code with a temporary INT3 - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits to userspace, and extend KVM "support" to all policy bits that don't require any actual support from KVM x86 (Intel): - Use the root role from kvm_mmu_page to construct EPTPs instead of the current vCPU state, partly as worthwhile cleanup, but mostly to pave the way for tracking per-root TLB flushes, and elide EPT flushes on pCPU migration if the root is clean from a previous flush - Add a few missing nested consistency checks - Rip out support for doing "early" consistency checks via hardware as the functionality hasn't been used in years and is no longer useful in general; replace it with an off-by-default module param to WARN if hardware fails a check that KVM does not perform - Fix a currently-benign bug where KVM would drop the guest's SPEC_CTRL[63:32] on VM-Enter - Misc cleanups - Overhaul the TDX code to address systemic races where KVM (acting on behalf of userspace) could inadvertantly trigger lock contention in the TDX-Module; KVM was either working around these in weird, ugly ways, or was simply oblivious to them (though even Yan's devilish selftests could only break individual VMs, not the host kernel) - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a TDX vCPU, if creating said vCPU failed partway through - Fix a few sparse warnings (bad annotation, 0 != NULL) - Use struct_size() to simplify copying TDX capabilities to userspace - Fix a bug where TDX would effectively corrupt user-return MSR values if the TDX Module rejects VP.ENTER and thus doesn't clobber host MSRs as expected Selftests: - Fix a math goof in mmu_stress_test when running on a single-CPU system/VM - Forcefully override ARCH from x86_64 to x86 to play nice with specifying ARCH=x86_64 on the command line - Extend a bunch of nested VMX to validate nested SVM as well - Add support for LA57 in the core VM_MODE_xxx macro, and add a test to verify KVM can save/restore nested VMX state when L1 is using 5-level paging, but L2 is not - Clean up the guest paging code in anticipation of sharing the core logic for nested EPT and nested NPT guest_memfd: - Add NUMA mempolicy support for guest_memfd, and clean up a variety of rough edges in guest_memfd along the way - Define a CLASS to automatically handle get+put when grabbing a guest_memfd from a memslot to make it harder to leak references - Enhance KVM selftests to make it easer to develop and debug selftests like those added for guest_memfd NUMA support, e.g. where test and/or KVM bugs often result in hard-to-debug SIGBUS errors - Misc cleanups Generic: - Use the recently-added WQ_PERCPU when creating the per-CPU workqueue for irqfd cleanup - Fix a goof in the dirty ring documentation - Fix choice of target for directed yield across different calls to kvm_vcpu_on_spin(); the function was always starting from the first vCPU instead of continuing the round-robin search" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (260 commits) KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2 KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX} KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected" KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot() KVM: arm64: Add endian casting to kvm_swap_s[12]_desc() KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n KVM: arm64: selftests: Add test for AT emulation KVM: arm64: nv: Expose hardware access flag management to NV guests KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW KVM: arm64: Implement HW access flag management in stage-1 SW PTW KVM: arm64: Propagate PTW errors up to AT emulation KVM: arm64: Add helper for swapping guest descriptor KVM: arm64: nv: Use pgtable definitions in stage-2 walk KVM: arm64: Handle endianness in read helper for emulated PTW KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW KVM: arm64: Call helper for reading descriptors directly KVM: arm64: nv: Advertise support for FEAT_XNX KVM: arm64: Teach ptdump about FEAT_XNX permissions KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions ...
2025-11-27KVM: s390: Enable and disable interrupts in entry codeHeiko Carstens
Move enabling and disabling of interrupts around the SIE instruction to entry code. Enabling interrupts only after the __TI_sie flag has been set guarantees that the SIE instruction is not executed if an interrupt happens between enabling interrupts and the execution of the SIE instruction. Interrupt handlers and machine check handler forward the PSW to the sie_exit label in such cases. This is a prerequisite for VIRT_XFER_TO_GUEST_WORK to prevent that guest context is entered when e.g. a scheduler IPI, indicating that a reschedule is required, happens right before the SIE instruction, which could lead to long delays. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-26s390/entry: Use lay instead of aghikHeiko Carstens
Use the lay instruction instead of aghik. aghik is only available since z196, therefore compiling the kernel for z10 results in this error: arch/s390/kernel/entry.S: Assembler messages: arch/s390/kernel/entry.S:165: Error: Unrecognized opcode: `aghik' Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202511261518.nBbQN5h7-lkp@intel.com/ Fixes: f5730d44e05e ("s390: Add stackprotector support") Reviewed-by: Jan Polensky <japo@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24s390: Add stackprotector supportHeiko Carstens
Stackprotector support was previously unavailable on s390 because by default compilers generate code which is not suitable for the kernel: the canary value is accessed via thread local storage, where the address of thread local storage is within access registers 0 and 1. Using those registers also for the kernel would come with a significant performance impact and more complicated kernel entry/exit code, since access registers contents would have to be exchanged on every kernel entry and exit. With the upcoming gcc 16 release new compiler options will become available which allow to generate code suitable for the kernel. [1] Compiler option -mstack-protector-guard=global instructs gcc to generate stackprotector code that refers to a global stackprotector canary value via symbol __stack_chk_guard. Access to this value is guaranteed to occur via larl and lgrl instructions. Furthermore, compiler option -mstack-protector-guard-record generates a section containing all code addresses that reference the canary value. To allow for per task canary values the instructions which load the address of __stack_chk_guard are patched so they access a lowcore field instead: a per task canary value is available within the task_struct of each task, and is written to the per-cpu lowcore location on each context switch. Also add sanity checks and debugging option to be consistent with other kernel code patching mechanisms. Full debugging output can be enabled with the following kernel command line options: debug_stackprotector bootdebug ignore_loglevel earlyprintk dyndbg="file stackprotector.c +p" Example debug output: stackprot: 0000021e402d4eda: c010005a9ae3 -> c01f00070240 where "<insn address>: <old insn> -> <new insn>". [1] gcc commit 0cd1f03939d5 ("s390: Support global stack protector") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17s390/syscalls: Switch to generic system call table generationHeiko Carstens
The s390 syscall.tbl format differs slightly from most others, and therefore requires an s390 specific system call table generation script. With compat support gone use the opportunity to switch to generic system call table generation. The abi for all 64 bit system calls is now common, since there is no need to specify if system call entry points are only for 64 bit anymore. Furthermore create the system call table in C instead of assembler code in order to get type checking for all system call functions contained within the table. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17s390: Remove compat supportHeiko Carstens
There shouldn't be any 31 bit code around anymore that matters. Remove the compat layer support required to run 31 bit code. Reason for removal is code simplification and reduced test effort. Note that this comes without any deprecation warnings added to config options, or kernel messages, since most likely those would be ignored anyway. If it turns out there is still a reason to keep the compat layer this can be reverted at any time in the future. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-07-21stackleak: Rename STACKLEAK to KSTACK_ERASEKees Cook
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-05-26Merge tag 's390-6.16-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Large rework of the protected key crypto code to allow for asynchronous handling without memory allocation - Speed up system call entry/exit path by re-implementing lazy ASCE handling - Add module autoload support for the diag288_wdt watchdog device driver - Get rid of s390 specific strcpy() and strncpy() implementations, and switch all remaining users to strscpy() when possible - Various other small fixes and improvements * tag 's390-6.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (51 commits) s390/pci: Serialize device addition and removal s390/pci: Allow re-add of a reserved but not yet removed device s390/pci: Prevent self deletion in disable_slot() s390/pci: Remove redundant bus removal and disable from zpci_release_device() s390/crypto: Extend protected key conversion retry loop s390/pci: Fix __pcilg_mio_inuser() inline assembly s390/ptrace: Always inline regs_get_kernel_stack_nth() and regs_get_register() s390/thread_info: Cleanup header includes s390/extmem: Add workaround for DCSS unload diag s390/crypto: Rework protected key AES for true asynch support s390/cpacf: Rework cpacf_pcc() to return condition code s390/mm: Fix potential use-after-free in __crst_table_upgrade() s390/mm: Add mmap_assert_write_locked() check to crst_table_upgrade() s390/string: Remove strcpy() implementation s390/con3270: Use strscpy() instead of strcpy() s390/boot: Use strspcy() instead of strcpy() s390: Simple strcpy() to strscpy() conversions s390/pkey/crypto: Introduce xflags param for pkey in-kernel API s390/pkey: Provide and pass xflags within pkey and zcrypt layers s390/uv: Remove uv_get_secret_metadata function ...
2025-05-05s390/entry: Fix last breaking event handling in case of stack corruptionHeiko Carstens
In case of stack corruption stack_invalid() is called and the expectation is that register r10 contains the last breaking event address. This dependency is quite subtle and broke a couple of years ago without that anybody noticed. Fix this by getting rid of the dependency and read the last breaking event address from lowcore. Fixes: 56e62a737028 ("s390: convert to generic entry") Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-04-14s390/mm: Reimplement lazy ASCE handlingHeiko Carstens
Reduce system call overhead time (round trip time for invoking a non-existent system call) by 25%. With the removal of set_fs() [1] lazy control register handling was removed in order to keep kernel entry and exit simple. However this made system calls slower. With the conversion to generic entry [2] and numerous follow up changes which simplified the entry code significantly, adding support for lazy asce handling doesn't add much complexity to the entry code anymore. In particular this means: - On kernel entry the primary asce is not modified and contains the user asce - Kernel accesses which require secondary-space mode (for example futex operations) are surrounded by enable_sacf_uaccess() and disable_sacf_uaccess() calls. enable_sacf_uaccess() sets the primary asce to kernel asce so that the sacf instruction can be used to switch to secondary-space mode. The primary asce is changed back to user asce with disable_sacf_uaccess(). The state of the control register which contains the primary asce is reflected with a new TIF_ASCE_PRIMARY bit. This is required on context switch so that the correct asce is restored for the scheduled in process. In result address spaces are now setup like this: CPU running in | %cr1 ASCE | %cr7 ASCE | %cr13 ASCE -----------------------------|-----------|-----------|----------- user space | user | user | kernel kernel (no sacf) | user | user | kernel kernel (during sacf uaccess) | kernel | user | kernel kernel (kvm guest execution) | guest | user | kernel In result cr1 control register content is not changed except for: - futex system calls - legacy s390 PCI system calls - the kvm specific cmpxchg_user_key() uaccess helper This leads to faster system call execution. [1] 87d598634521 ("s390/mm: remove set_fs / rework address space handling") [2] 56e62a737028 ("s390: convert to generic entry") Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-03-31s390/entry: Fix setting _CIF_MCCK_GUEST with lowcore relocationSven Schnelle
When lowcore relocation is enabled, the machine check handler doesn't use the lowcore address when setting _CIF_MCCK_GUEST. Fix this by adding the missing base register. Fixes: 0001b7bbc53a ("s390/entry: Make mchk_int_handler() ready for lowcore relocation") Reported-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-04s390/traps: Change stack overflow messageSven Schnelle
When the kernel stack pointer is pointing to invalid memory, a 'Kernel stack overflow' message is printed, which is misleading. Change the message to actually say that the stack pointer is invalid instead. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-04s390: Use system header file variant of include directiveHeiko Carstens
A few include directives use the local search variant even though the files to be included aren't local. Therefore use the normal system header file variant of the include directive. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-04s390/lowcore: Convert relocated lowcore alternative to machine featureHeiko Carstens
Convert the explicit relocated lowcore alternative type to a more generic machine feature. This only reduces the number of alternative types, but has no impact on code generation. Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-12-10s390/Kconfig: Select VMAP_STACK unconditionallyHeiko Carstens
There is no point in supporting !VMAP_STACK kernel builds. VMAP_STACK has proven to work since many years. Also, since KASAN_VMALLOC is supported, kernels built with !VMAP_STACK are completely untested. Therefore select VMAP_STACK unconditionally and remove all config options and code required for !VMAP_STACK builds. Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-11-21s390/entry: Mark IRQ entries to fix stack depot warningsVasily Gorbik
The stack depot filters out everything outside of the top interrupt context as an uninteresting or irrelevant part of the stack traces. This helps with stack trace de-duplication, avoiding an explosion of saved stack traces that share the same IRQ context code path but originate from different randomly interrupted points, eventually exhausting the stack depot. Filtering uses in_irqentry_text() to identify functions within the .irqentry.text and .softirqentry.text sections, which then become the last stack trace entries being saved. While __do_softirq() is placed into the .softirqentry.text section by common code, populating .irqentry.text is architecture-specific. Currently, the .irqentry.text section on s390 is empty, which prevents stack depot filtering and de-duplication and could result in warnings like: Stack depot reached limit capacity WARNING: CPU: 0 PID: 286113 at lib/stackdepot.c:252 depot_alloc_stack+0x39a/0x3c8 with PREEMPT and KASAN enabled. Fix this by moving the IO/EXT interrupt handlers from .kprobes.text into the .irqentry.text section and updating the kprobes blacklist to include the .irqentry.text section. This is done only for asynchronous interrupts and explicitly not for program checks, which are synchronous and where the context beyond the program check is important to preserve. Despite machine checks being somewhat in between, they are extremely rare, and preserving context when possible is also of value. SVCs and Restart Interrupts are not relevant, one being always at the boundary to user space and the other being a one-time thing. IRQ entries filtering is also optionally used in ftrace function graph, where the same logic applies. Cc: stable@vger.kernel.org # 5.15+ Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm/fault: Handle guest-related program interrupts in KVMClaudio Imbrenda
Any program interrupt that happens in the host during the execution of a KVM guest will now short circuit the fault handler and return to KVM immediately. Guest fault handling (including pfault) will happen entirely inside KVM. When sie64a() returns zero, current->thread.gmap_int_code will contain the program interrupt number that caused the exit, or zero if the exit was not caused by a host program interrupt. KVM will now take care of handling all guest faults in vcpu_post_run(). Since gmap faults will not be visible by the rest of the kernel, remove GMAP_FAULT, the linux fault handlers for secure execution faults, the exception table entries for the sie instruction, the nop padding after the sie instruction, and all other references to guest faults from the s390 code. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-6-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/entry: Remove __GMAP_ASCE and use _PIF_GUEST_FAULT againClaudio Imbrenda
Now that the guest ASCE is passed as a parameter to __sie64a(), _PIF_GUEST_FAULT can be used again to determine whether the fault was a guest or host fault. Since the guest ASCE will not be taken from the gmap pointer in lowcore anymore, __GMAP_ASCE can be removed. For the same reason the guest ASCE needs now to be saved into the cr1 save area unconditionally. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-2-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-21Merge tag 's390-6.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Optimize ftrace and kprobes code patching and avoid stop machine for kprobes if sequential instruction fetching facility is available - Add hiperdispatch feature to dynamically adjust CPU capacity in vertical polarization to improve scheduling efficiency and overall performance. Also add infrastructure for handling warning track interrupts (WTI), allowing for graceful CPU preemption - Rework crypto code pkey module and split it into separate, independent modules for sysfs, PCKMO, CCA, and EP11, allowing modules to load only when the relevant hardware is available - Add hardware acceleration for HMAC modes and the full AES-XTS cipher, utilizing message-security assist extensions (MSA) 10 and 11. It introduces new shash implementations for HMAC-SHA224/256/384/512 and registers the hardware-accelerated AES-XTS cipher as the preferred option. Also add clear key token support - Add MSA 10 and 11 processor activity instrumentation counters to perf and update PAI Extension 1 NNPA counters - Cleanup cpu sampling facility code and rework debug/WARN_ON_ONCE statements - Add support for SHA3 performance enhancements introduced with MSA 12 - Add support for the query authentication information feature of MSA 13 and introduce the KDSA CPACF instruction. Provide query and query authentication information in sysfs, enabling tools like cpacfinfo to present this data in a human-readable form - Update kernel disassembler instructions - Always enable EXPOLINE_EXTERN if supported by the compiler to ensure kpatch compatibility - Add missing warning handling and relocated lowcore support to the early program check handler - Optimize ftrace_return_address() and avoid calling unwinder - Make modules use kernel ftrace trampolines - Strip relocs from the final vmlinux ELF file to make it roughly 2 times smaller - Dump register contents and call trace for early crashes to the console - Generate ptdump address marker array dynamically - Fix rcu_sched stalls that might occur when adding or removing large amounts of pages at once to or from the CMM balloon - Fix deadlock caused by recursive lock of the AP bus scan mutex - Unify sync and async register save areas in entry code - Cleanup debug prints in crypto code - Various cleanup and sanitizing patches for the decompressor - Various small ftrace cleanups * tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (84 commits) s390/crypto: Display Query and Query Authentication Information in sysfs s390/crypto: Add Support for Query Authentication Information s390/crypto: Rework RRE and RRF CPACF inline functions s390/crypto: Add KDSA CPACF Instruction s390/disassembler: Remove duplicate instruction format RSY_RDRU s390/boot: Move boot_printk() code to own file s390/boot: Use boot_printk() instead of sclp_early_printk() s390/boot: Rename decompressor_printk() to boot_printk() s390/boot: Compile all files with the same march flag s390: Use MARCH_HAS_*_FEATURES defines s390: Provide MARCH_HAS_*_FEATURES defines s390/facility: Disable compile time optimization for decompressor code s390/boot: Increase minimum architecture to z10 s390/als: Remove obsolete comment s390/sha3: Fix SHA3 selftests failures s390/pkey: Add AES xts and HMAC clear key token support s390/cpacf: Add MSA 10 and 11 new PCKMO functions s390/mm: Add cond_resched() to cmm_alloc/free_pages() s390/pai_ext: Update PAI extension 1 counters s390/pai_crypto: Add support for MSA 10 and 11 pai counters ...
2024-09-13s390/alternatives: Remove ALT_FACILITY_EARLYHeiko Carstens
Patch all alternatives which depend on facilities from the decompressor. There is no technical reason which enforces to split patching of such alternatives to the decompressor and the kernel. This simplifies alternative handling a bit, since one alternative type is removed. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-29s390/entry: Unify save_area_sync and save_area_asyncSven Schnelle
In the past two save areas existed because interrupt handlers and system call / program check handlers where entered with interrupts enabled. To prevent a handler from overwriting the save areas from the previous handler, interrupts used the async save area, while system call and program check handler used the sync save area. Since the removal of critical section cleanup from entry.S, handlers are entered with interrupts disabled. When the interrupts are re-enabled, the save area is no longer need. Therefore merge both save areas into one. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-07s390/entry: Move early_pgm_check_handler() to init text sectionHeiko Carstens
Save some bytes and move early_pgm_check_handler() to init text section. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-07s390/entry: Make early program check handler relocated lowcore awareHeiko Carstens
Add the missing pieces so the early program check handler also works with a relocated lowcore. Right now the result of an early program check in case of a relocated lowcore would be a program check loop. Fixes: 8f1e70adb1a3 ("s390/boot: Add cmdline option to relocate lowcore") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-08-07s390/entry: Move early program check handler to entry.SHeiko Carstens
Have all program check handlers in one file to make future changes easy. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make system_call() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in system_call(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make ret_from_fork() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in ret_from_fork(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make __switch_to() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in __switch_to(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make restart_int_handler() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in restart_int_handler(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make mchk_int_handler() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in mcck_int_handler(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make int handlers ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in the ext/io interrupt handlers. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make pgm_check_handler() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in pgm_check_handler(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Add base register to CHECK_VMAP_STACK/CHECK_STACK macroSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to CHECK_VMAP_STACK and CHECK_STACK. No functional change, because %r0 is passed to the macro. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Add base register to SIEEXIT macroSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to SIEEXIT. No functional change, because %r0 is passed to the macro. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Add base register to MBEAR macroSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to MBEAR. No functional change, because %r0 is passed to the macro. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make __sie64a() ready for lowcore relocationSven Schnelle
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in __sie64a(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Move SIE indicator flag to thread infoHeiko Carstens
CIF_SIE indicates if a thread is running in SIE context. This is the state of a thread and not the CPU. Therefore move this indicator to thread info. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/nmi: Simplify ptregs setupHeiko Carstens
The low level machine check handler code fills the ptregs structure partially with the register contents present at machine check handler entry and partially with contents from the machine check save area. In case of a machine check the contents of all general purpose registers are saved by the CPU to the machine check save area. Therefore simplify the code and fill the ptregs structure by only using the machine check save area as source. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/nospec: Push down alternative handlingHeiko Carstens
The nospec implementation is deeply integrated into the alternatives code: only for nospec an alternative facility list is implemented and used by the alternative code, while it is modified by nospec specific needs. Push down the nospec alternative handling into the nospec by introducing a new alternative type and a specific nospec callback to decide if alternatives should be applied. Also introduce a new global nobp variable which together with facility 82 can be used to decide if nobp is enabled or not. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/alternatives: Rework to allow for callbacksHeiko Carstens
Rework alternatives to allow for callbacks. With this every alternative entry has additional data encoded: - When (aka context) an alternative is supposed to be applied - The type of an alternative, which allows for type specific handling and callbacks - Extra type specific payload (patch information), which can be passed to callbacks in order to decide if an alternative should be applied or not With this only the "late" context is implemented, which means there is no change to the previous behaviour. All code is just converted to the more generic new infrastructure. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/alternatives: Merge both alternative header filesHeiko Carstens
The two alternative header files must stay in sync. This is easier to achieve within one header file. Therefore merge both of them and have only one file, like most other architectures. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390: Move CIF flags to struct pcpuSven Schnelle
To allow testing flags for offline CPUs, move the CIF flags to struct pcpu. To avoid having to calculate the array index for each access, add a pointer to the pcpu member for the current cpu to lowcore. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-10s390/entry: Pass the asce as parameter to sie64a()Claudio Imbrenda
Pass the guest ASCE explicitly as parameter, instead of having sie64a() take it from lowcore. This removes hidden state from lowcore, and makes things look cleaner. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Link: https://lore.kernel.org/r/20240703155900.103783-2-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-05-14s390/idle: Rewrite psw_idle() in CSven Schnelle
To ease maintenance and further enhancements, convert the psw_idle() function to C. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/mm: Fix NULL pointer dereferenceSven Schnelle
The recently added check to figure out if a fault happened on gmap ASCE dereferences the gmap pointer in lowcore without checking that it is not NULL. For all non-KVM processes the pointer is NULL, so that some value from lowcore will be read. With the current layouts of struct gmap and struct lowcore the read value (aka ASCE) is zero, so that this doesn't lead to any observable bug; at least currently. Fix this by adding the missing NULL pointer check. Fixes: 64c3431808bd ("s390/entry: compare gmap asce to determine guest/host fault") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-03s390/entry: align system call table on 8 bytesSumanth Korikkar
Align system call table on 8 bytes. With sys_call_table entry size of 8 bytes that eliminates the possibility of a system call pointer crossing cache line boundary. Cc: stable@kernel.org Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-03-17s390/entry: compare gmap asce to determine guest/host faultSven Schnelle
With the current implementation, there are some cornercases where a host fault would be treated as a guest fault, for example when the sie instruction causes a program check. Therefore store the gmap asce in ptregs, and use that to compare the primary asce from the fault instead of matching instruction addresses. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-17s390/entry: remove OUTSIDE macroSven Schnelle
With only one OUTSIDE user left, remove the macro and move the code directly to the machine check handler. This has the advantage that it is much easier to determine which registers are used. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-17s390/entry: add CIF_SIE flag and remove sie64a() address checkSven Schnelle
When a program check, interrupt or machine check is triggered, the PSW address is compared to a certain range of the sie64a() function to figure out whether SIE was interrupted and a cleanup of SIE is needed. This doesn't work with kprobes: If kprobes probes an instruction, it copies the instruction to the kprobes instruction page and overwrites the original instruction with an undefind instruction (Opcode 00). When this instruction is hit later, kprobes single-steps the instruction on the kprobes_instruction page. However, if this instruction is a relative branch instruction it will now point to a different location in memory due to being moved to the kprobes instruction page. If the new branch target points into sie64a() the kernel assumes it interrupted SIE when processing the breakpoint and will crash trying to access the SIE control block. Instead of comparing the address, introduce a new CIF_SIE flag which indicates whether SIE was interrupted. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16s390/kvm: convert to regular kernel fpu userHeiko Carstens
KVM modifies the kernel fpu's regs pointer to its own area to implement its custom version of preemtible kernel fpu context. With general support for preemptible kernel fpu context there is no need for the extra complexity in KVM code anymore. Therefore convert KVM to a regular kernel fpu user. In particular this means that all TIF_FPU checks can be removed, since the fpu register context will never be changed by other kernel fpu users, and also the fpu register context will be restored if a thread is preempted. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16s390/fpu: convert FPU CIF flag to regular TIF flagHeiko Carstens
The FPU state, as represented by the CIF_FPU flag reflects the FPU state of a task, not the CPU it is running on. Therefore convert the flag to a regular TIF flag. This removes the magic in switch_to() where a save_fpu_regs() call for the currently (previous) running task sets the per-cpu CIF_FPU flag, which is required to restore FPU register contents of the next task, when it returns to user space. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>