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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 ...
2025-12-02Merge tag 'kvm-s390-next-6.19-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - SCA rework - VIRT_XFER_TO_GUEST_WORK support - Operation exception forwarding support - Cleanups
2025-11-28KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functionsAndrew Donnellan
Switch to using the generic infrastructure to check for and handle pending work before transitioning into guest mode. xfer_to_guest_mode_handle_work() does a few more things than the current code does when deciding whether or not to exit the __vcpu_run() loop. The exittime tests from kvm-unit-tests, in my tests, were within a few percent compared to before this series, which is within noise tolerance. Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> [frankja@linux.ibm.com: Removed semicolon] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
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>
2025-11-27KVM: s390: Add signal_exits counterAndrew Donnellan
Add a signal_exits counter for s390, as exists on arm64, loongarch, mips, powerpc, riscv and x86. This is used by kvm_handle_signal_exit(), which we will use when we later enable CONFIG_VIRT_XFER_TO_GUEST_WORK. 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>
2025-11-24s390: Remove KMSG_COMPONENT macroHeiko Carstens
The KMSG_COMPONENT macro is a leftover of the s390 specific "kernel message catalog" which never made it upstream. Remove the macro in order to get rid of a pointless indirection. Replace all users with the string it defines. In almost all cases this leads to a simple replacement like this: - #define KMSG_COMPONENT "appldata" - #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + #define pr_fmt(fmt) "appldata: " fmt Except for some special cases this is just mechanical/scripted work. Acked-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-21KVM: s390: vsie: Check alignment of BSCA headerEric Farman
The VSIE code currently checks that the BSCA struct fits within a page, and returns a validity exception 0x003b if it doesn't. The BSCA is pinned in memory rather than shadowed (see block comment at end of kvm_s390_cpu_feat_init()), so enforcing the CPU entries to be on the same pinned page makes sense. Except those entries aren't going to be used below the guest, and according to the definition of that validity exception only the header of the BSCA (everything but the CPU entries) needs to be within a page. Adjust the alignment check to account for that. Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-21KVM: s390: Add capability that forwards operation exceptionsJanosch Frank
Setting KVM_CAP_S390_USER_OPEREXEC will forward all operation exceptions to user space. This also includes the 0x0000 instructions managed by KVM_CAP_S390_USER_INSTR0. It's helpful if user space wants to emulate instructions which do not (yet) have an opcode. While we're at it refine the documentation for KVM_CAP_S390_USER_INSTR0. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-17s390/kvm: Use psw32_t instead of psw_compat_tHeiko Carstens
kvm_s390_handle_lpsw() make use of the psw_compat_t type even though the code has nothing to do with CONFIG_COMPAT, for which the type is supposed to be used. Use psw32_t instead. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-05KVM: Rename kvm_arch_vcpu_async_ioctl() to kvm_arch_vcpu_unlocked_ioctl()Sean Christopherson
Rename the "async" ioctl API to "unlocked" so that upcoming usage in x86's TDX code doesn't result in a massive misnomer. To avoid having to retry SEAMCALLs, TDX needs to acquire kvm->lock *and* all vcpu->mutex locks, and acquiring all of those locks after/inside the current vCPU's mutex is a non-starter. However, TDX also needs to acquire the vCPU's mutex and load the vCPU, i.e. the handling is very much not async to the vCPU. No functional change intended. Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> Tested-by: Yan Zhao <yan.y.zhao@intel.com> Tested-by: Kai Huang <kai.huang@intel.com> Link: https://patch.msgid.link/20251030200951.3402865-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-11-05KVM: Make support for kvm_arch_vcpu_async_ioctl() mandatorySean Christopherson
Implement kvm_arch_vcpu_async_ioctl() "natively" in x86 and arm64 instead of relying on an #ifdef'd stub, and drop HAVE_KVM_VCPU_ASYNC_IOCTL in anticipation of using the API on x86. Once x86 uses the API, providing a stub for one architecture and having all other architectures opt-in requires more code than simply implementing the API in the lone holdout. Eliminating the Kconfig will also reduce churn if the API is renamed in the future (spoiler alert). No functional change intended. Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> Tested-by: Yan Zhao <yan.y.zhao@intel.com> Tested-by: Kai Huang <kai.huang@intel.com> Link: https://patch.msgid.link/20251030200951.3402865-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-10-20KVM: s390: Replace sprintf with snprintf for buffer safetyJosephine Pfeiffer
Replace sprintf() with snprintf() when formatting debug names to prevent potential buffer overflow. The debug_name buffer is 16 bytes, and while unlikely to overflow with current PIDs, using snprintf() provides proper bounds checking. Signed-off-by: Josephine Pfeiffer <hi@josie.lol> [frankja@linux.ibm.com: Fixed subject prefix] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-10-20KVM: s390: Remove unused return variable in kvm_arch_vcpu_ioctl_set_fpuThorsten Blum
kvm_arch_vcpu_ioctl_set_fpu() always returns 0 and the local return variable 'ret' is not used anymore. Remove it. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-10-20KVM: S390: Remove sca_lockChristoph Schlameuss
Since we are no longer switching from a BSCA to a ESCA we can completely get rid of the sca_lock. The write lock was only taken for that conversion. After removal of the lock some local code cleanups are possible. Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Suggested-by: Janosch Frank <frankja@linux.ibm.com> [frankja@linux.ibm.com: Added suggested-by tag as discussed on list] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-10-20KVM: s390: Use ESCA instead of BSCA at VM initChristoph Schlameuss
All modern IBM Z and Linux One machines do offer support for the Extended System Control Area (ESCA). The ESCA is available since the z114/z196 released in 2010. KVM needs to allocate and manage the SCA for guest VMs. Prior to this change the SCA was setup as Basic SCA only supporting a maximum of 64 vCPUs when initializing the VM. With addition of the 65th vCPU the SCA was needed to be converted to a ESCA. Instead of allocating a BSCA and upgrading it for PV or when adding the 65th cpu we can always allocate the ESCA directly upon VM creation simplifying the code in multiple places as well as completely removing the need to convert an existing SCA. In cases where the ESCA is not supported (z10 and earlier) the use of the SCA entries and with that SIGP interpretation are disabled for VMs. This increases the number of exits from the VM in multiprocessor scenarios and thus decreases performance. The same is true for VSIE where SIGP is currently disabled and thus no SCA entries are used. The only downside of the change is that we will always allocate 4 pages for a 248 cpu ESCA instead of a single page for the BSCA per VM. In return we can delete a bunch of checks and special handling depending on the SCA type as well as the whole BSCA to ESCA conversion. With that behavior change we are no longer referencing a bsca_block in kvm->arch.sca. This will always be esca_block instead. By specifying the type of the sca as esca_block we can simplify access to the sca and get rid of some helpers while making the code clearer. KVM_MAX_VCPUS is also moved to kvm_host_types to allow using this in future type definitions. Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-10-09Merge tag 's390-6.18-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - Compile the decompressor with -Wno-pointer-sign flag to avoid a clang warning - Fix incomplete conversion to flag output macros in __xsch(), to avoid always zero return value instead of the expected condition code - Remove superfluous newlines from inline assemblies to improve compiler inlining decisions - Expose firmware provided UID Checking state in sysfs regardless of the device presence or state - CIO does not unregister subchannels when the attached device is invalid or unavailable. Update the purge function to remove I/O subchannels if the device number is found on cio_ignore list - Consolidate PAI crypto allocation and cleanup paths - The uv_get_secret_metadata() function has been removed some few months ago, remove also the function mention it in a comment * tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/uv: Fix comment of uv_find_secret() function s390/pai_crypto: Consolidate PAI crypto allocation and cleanup paths s390/cio: Update purge function to unregister the unused subchannels s390/pci: Expose firmware provided UID Checking state in sysfs s390: Remove superfluous newlines from inline assemblies s390/cio/ioasm: Fix __xsch() condition code handling s390: Add -Wno-pointer-sign to KBUILD_CFLAGS_DECOMPRESSOR
2025-09-30KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalentSean Christopherson
Use kvm_is_gpa_in_memslot() to check the validity of the notification indicator byte address instead of open coding equivalent logic in the VFIO AP driver. Opportunistically use a dedicated wrapper that exists and is exported expressly for the VFIO AP module. kvm_is_gpa_in_memslot() is generally unsuitable for use outside of KVM; other drivers typically shouldn't rely on KVM's memslots, and using the API requires kvm->srcu (or slots_lock) to be held for the entire duration of the usage, e.g. to avoid TOCTOU bugs. handle_pqap() is a bit of a special case, as it's explicitly invoked from KVM with kvm->srcu already held, and the VFIO AP driver is in many ways an extension of KVM that happens to live in a separate module. Providing a dedicated API for the VFIO AP driver will allow restricting the vast majority of generic KVM's exports to KVM submodules (e.g. to x86's kvm-{amd,intel}.ko vendor mdoules). No functional change intended. Acked-by: Anthony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20250919003303.1355064-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30Merge tag 'loongarch-kvm-6.18' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.18 1. Add PTW feature detection on new hardware. 2. Add sign extension with kernel MMIO/IOCSR emulation. 3. Improve in-kernel IPI emulation. 4. Improve in-kernel PCH-PIC emulation. 5. Move kvm_iocsr tracepoint out of generic code.
2025-09-30Merge tag 'kvm-s390-next-6.18-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: A bugfix and a performance improvement * Improve interrupt cpu for wakeup, change the heuristic to decide wich vCPU to deliver a floating interrupt to. * Clear the pte when discarding a swapped page because of CMMA; this bug was introduced in 6.16 when refactoring gmap code.
2025-09-29s390: Remove superfluous newlines from inline assembliesHeiko Carstens
Remove superfluous newlines from inline assemblies. Compilers use the number of lines of inline assemblies as heuristic for the complexity and inline decisions. Therefore inline assemblies should only contain as many lines as required. A lot of inline assemblies contain a superfluous newline for the last line. Remove such newlines to improve compiler inlining decisions. Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-09KVM: s390: Fix FOLL_*/FAULT_FLAG_* confusionClaudio Imbrenda
Pass the right type of flag to vcpu_dat_fault_handler(); it expects a FOLL_* flag (in particular FOLL_WRITE), but FAULT_FLAG_WRITE is passed instead. This still works because they happen to have the same integer value, but it's a mistake, thus the fix. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 05066cafa925 ("s390/mm/fault: Handle guest-related program interrupts in KVM") Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-09-09KVM: s390: Fix incorrect usage of mmu_notifier_register()Claudio Imbrenda
If mmu_notifier_register() fails, for example because a signal was pending, the mmu_notifier will not be registered. But when the VM gets destroyed, it will get unregistered anyway and that will cause one extra mmdrop(), which will eventually cause the mm of the process to be freed too early, and cause a use-after free. This bug happens rarely, and only when secure guests are involved. The solution is to check the return value of mmu_notifier_register() and return it to the caller (ultimately it will be propagated all the way to userspace). In case of -EINTR, userspace will try again. Fixes: ca2fd0609b5d ("KVM: s390: pv: add mmu_notifier") Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-09-09KVM: s390: Fix access to unavailable adapter indicator pages during postcopyThomas Huth
When you run a KVM guest with vhost-net and migrate that guest to another host, and you immediately enable postcopy after starting the migration, there is a big chance that the network connection of the guest won't work anymore on the destination side after the migration. With a debug kernel v6.16.0, there is also a call trace that looks like this: FAULT_FLAG_ALLOW_RETRY missing 881 CPU: 6 UID: 0 PID: 549 Comm: kworker/6:2 Kdump: loaded Not tainted 6.16.0 #56 NONE Hardware name: IBM 3931 LA1 400 (LPAR) Workqueue: events irqfd_inject [kvm] Call Trace: [<00003173cbecc634>] dump_stack_lvl+0x104/0x168 [<00003173cca69588>] handle_userfault+0xde8/0x1310 [<00003173cc756f0c>] handle_pte_fault+0x4fc/0x760 [<00003173cc759212>] __handle_mm_fault+0x452/0xa00 [<00003173cc7599ba>] handle_mm_fault+0x1fa/0x6a0 [<00003173cc73409a>] __get_user_pages+0x4aa/0xba0 [<00003173cc7349e8>] get_user_pages_remote+0x258/0x770 [<000031734be6f052>] get_map_page+0xe2/0x190 [kvm] [<000031734be6f910>] adapter_indicators_set+0x50/0x4a0 [kvm] [<000031734be7f674>] set_adapter_int+0xc4/0x170 [kvm] [<000031734be2f268>] kvm_set_irq+0x228/0x3f0 [kvm] [<000031734be27000>] irqfd_inject+0xd0/0x150 [kvm] [<00003173cc00c9ec>] process_one_work+0x87c/0x1490 [<00003173cc00dda6>] worker_thread+0x7a6/0x1010 [<00003173cc02dc36>] kthread+0x3b6/0x710 [<00003173cbed2f0c>] __ret_from_fork+0xdc/0x7f0 [<00003173cdd737ca>] ret_from_fork+0xa/0x30 3 locks held by kworker/6:2/549: #0: 00000000800bc958 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7ee/0x1490 #1: 000030f3d527fbd0 ((work_completion)(&irqfd->inject)){+.+.}-{0:0}, at: process_one_work+0x81c/0x1490 #2: 00000000f99862b0 (&mm->mmap_lock){++++}-{3:3}, at: get_map_page+0xa8/0x190 [kvm] The "FAULT_FLAG_ALLOW_RETRY missing" indicates that handle_userfaultfd() saw a page fault request without ALLOW_RETRY flag set, hence userfaultfd cannot remotely resolve it (because the caller was asking for an immediate resolution, aka, FAULT_FLAG_NOWAIT, while remote faults can take time). With that, get_map_page() failed and the irq was lost. We should not be strictly in an atomic environment here and the worker should be sleepable (the call is done during an ioctl from userspace), so we can allow adapter_indicators_set() to just sleep waiting for the remote fault instead. Link: https://issues.redhat.com/browse/RHEL-42486 Signed-off-by: Peter Xu <peterx@redhat.com> [thuth: Assembled patch description and fixed some cosmetical issues] Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Fixes: f65470661f36 ("KVM: s390/interrupt: do not pin adapter interrupt pages") [frankja: Added fixes tag] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-09-08KVM: s390: improve interrupt cpu for wakeupChristian Borntraeger
Turns out that picking an idle CPU for floating interrupts has some negative side effects. The guest will keep the IO workload on its CPU and rather use an IPI from the interrupt CPU instead of moving workload. For example a guest with 2 vCPUs and 1 fio process might run that fio on vcpu1. If after diag500 both vCPUs are idle then vcpu0 is woken up. The guest will then do an IPI from vcpu0 to vcpu1. So lets change the heuristics and prefer the last CPU that went to sleep. This one is likely still in halt polling and can be woken up quickly. This patch shows significant improvements in terms of bandwidth or cpu consumption for fio and uperf workloads and seems to be a net win. Link: https://lore.kernel.org/linux-s390/20250904113927.119306-1-borntraeger@linux.ibm.com/ Reviewed-by: Christoph Schlameuß <schlameuss@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2025-07-30Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Host driver for GICv5, the next generation interrupt controller for arm64, including support for interrupt routing, MSIs, interrupt translation and wired interrupts - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on GICv5 hardware, leveraging the legacy VGIC interface - Userspace control of the 'nASSGIcap' GICv3 feature, allowing userspace to disable support for SGIs w/o an active state on hardware that previously advertised it unconditionally - Map supporting endpoints with cacheable memory attributes on systems with FEAT_S2FWB and DIC where KVM no longer needs to perform cache maintenance on the address range - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest hypervisor to inject external aborts into an L2 VM and take traps of masked external aborts to the hypervisor - Convert more system register sanitization to the config-driven implementation - Fixes to the visibility of EL2 registers, namely making VGICv3 system registers accessible through the VGIC device instead of the ONE_REG vCPU ioctls - Various cleanups and minor fixes LoongArch: - Add stat information for in-kernel irqchip - Add tracepoints for CPUCFG and CSR emulation exits - Enhance in-kernel irqchip emulation - Various cleanups RISC-V: - Enable ring-based dirty memory tracking - Improve perf kvm stat to report interrupt events - Delegate illegal instruction trap to VS-mode - MMU improvements related to upcoming nested virtualization s390x - Fixes x86: - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC, and PIT emulation at compile time - Share device posted IRQ code between SVM and VMX and harden it against bugs and runtime errors - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1) instead of O(n) - For MMIO stale data mitigation, track whether or not a vCPU has access to (host) MMIO based on whether the page tables have MMIO pfns mapped; using VFIO is prone to false negatives - Rework the MSR interception code so that the SVM and VMX APIs are more or less identical - Recalculate all MSR intercepts from scratch on MSR filter changes, instead of maintaining shadow bitmaps - Advertise support for LKGS (Load Kernel GS base), a new instruction that's loosely related to FRED, but is supported and enumerated independently - Fix a user-triggerable WARN that syzkaller found by setting the vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting the vCPU into VMX Root Mode (post-VMXON). Trying to detect every possible path leading to architecturally forbidden states is hard and even risks breaking userspace (if it goes from valid to valid state but passes through invalid states), so just wait until KVM_RUN to detect that the vCPU state isn't allowed - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of APERF/MPERF reads, so that a "properly" configured VM can access APERF/MPERF. This has many caveats (APERF/MPERF cannot be zeroed on vCPU creation or saved/restored on suspend and resume, or preserved over thread migration let alone VM migration) but can be useful whenever you're interested in letting Linux guests see the effective physical CPU frequency in /proc/cpuinfo - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been created, as there's no known use case for changing the default frequency for other VM types and it goes counter to the very reason why the ioctl was added to the vm file descriptor. And also, there would be no way to make it work for confidential VMs with a "secure" TSC, so kill two birds with one stone - Dynamically allocation the shadow MMU's hashed page list, and defer allocating the hashed list until it's actually needed (the TDP MMU doesn't use the list) - Extract many of KVM's helpers for accessing architectural local APIC state to common x86 so that they can be shared by guest-side code for Secure AVIC - Various cleanups and fixes x86 (Intel): - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest. Failure to honor FREEZE_IN_SMM can leak host state into guests - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF x86 (AMD): - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the nested SVM MSRPM offsets tracker can't handle an MSR (which is pretty much a static condition and therefore should never happen, but still) - Fix a variety of flaws and bugs in the AVIC device posted IRQ code - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware supports) instead of rejecting vCPU creation - Extend enable_ipiv module param support to SVM, by simply leaving IsRunning clear in the vCPU's physical ID table entry - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by erratum #1235, to allow (safely) enabling AVIC on such CPUs - Request GA Log interrupts if and only if the target vCPU is blocking, i.e. only if KVM needs a notification in order to wake the vCPU - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the vCPU's CPUID model - Accept any SNP policy that is accepted by the firmware with respect to SMT and single-socket restrictions. An incompatible policy doesn't put the kernel at risk in any way, so there's no reason for KVM to care - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and use WBNOINVD instead of WBINVD when possible for SEV cache maintenance - When reclaiming memory from an SEV guest, only do cache flushes on CPUs that have ever run a vCPU for the guest, i.e. don't flush the caches for CPUs that can't possibly have cache lines with dirty, encrypted data Generic: - Rework irqbypass to track/match producers and consumers via an xarray instead of a linked list. Using a linked list leads to O(n^2) insertion times, which is hugely problematic for use cases that create large numbers of VMs. Such use cases typically don't actually use irqbypass, but eliminating the pointless registration is a future problem to solve as it likely requires new uAPI - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *", to avoid making a simple concept unnecessarily difficult to understand - Decouple device posted IRQs from VFIO device assignment, as binding a VM to a VFIO group is not a requirement for enabling device posted IRQs - Clean up and document/comment the irqfd assignment code - Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e. ensure an eventfd is bound to at most one irqfd through the entire host, and add a selftest to verify eventfd:irqfd bindings are globally unique - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues related to private <=> shared memory conversions - Drop guest_memfd's .getattr() implementation as the VFS layer will call generic_fillattr() if inode_operations.getattr is NULL - Fix issues with dirty ring harvesting where KVM doesn't bound the processing of entries in any way, which allows userspace to keep KVM in a tight loop indefinitely - Kill off kvm_arch_{start,end}_assignment() and x86's associated tracking, now that KVM no longer uses assigned_device_count as a heuristic for either irqbypass usage or MDS mitigation Selftests: - Fix a comment typo - Verify KVM is loaded when getting any KVM module param so that attempting to run a selftest without kvm.ko loaded results in a SKIP message about KVM not being loaded/enabled (versus some random parameter not existing) - Skip tests that hit EACCES when attempting to access a file, and print a "Root required?" help message. In most cases, the test just needs to be run with elevated permissions" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits) Documentation: KVM: Use unordered list for pre-init VGIC registers RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map() RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs RISC-V: perf/kvm: Add reporting of interrupt events RISC-V: KVM: Enable ring-based dirty memory tracking RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap RISC-V: KVM: Delegate illegal instruction fault to VS mode RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs RISC-V: KVM: Factor-out g-stage page table management RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence RISC-V: KVM: Introduce struct kvm_gstage_mapping RISC-V: KVM: Factor-out MMU related declarations into separate headers RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect() RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range() RISC-V: KVM: Don't flush TLB when PTE is unchanged RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize() RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init() RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list ...
2025-07-21KVM: s390: Rework guest entry logicMark Rutland
In __vcpu_run() and do_vsie_run(), we enter an RCU extended quiescent state (EQS) by calling guest_enter_irqoff(), which lasts until __vcpu_run() calls guest_exit_irqoff(). However, between the two we enable interrupts and may handle interrupts during the EQS. As the IRQ entry code will not wake RCU in this case, we may run the core IRQ code and IRQ handler without RCU watching, leading to various potential problems. It is necessary to unmask (host) interrupts around entering the guest, as entering the guest via SIE will not automatically unmask these. When a host interrupt is taken from a guest, it is taken via its regular host IRQ handler rather than being treated as a direct exit from SIE. Due to this, we cannot simply mask interrupts around guest entry, and must handle interrupts during this window, waking RCU as required. Additionally, between guest_enter_irqoff() and guest_exit_irqoff(), we use local_irq_enable() and local_irq_disable() to unmask interrupts, violating the ordering requirements for RCU/lockdep/tracing around entry/exit sequences. Further, since this occurs in an instrumentable function, it's possible that instrumented code runs during this window, with potential usage of RCU, etc. To fix the RCU wakeup problem, an s390 implementation of arch_in_rcu_eqs() is added which checks for PF_VCPU in current->flags. PF_VCPU is set/cleared by guest_timing_{enter,exit}_irqoff(), which surround the actual guest entry. To fix the remaining issues, the lower-level guest entry logic is moved into a shared noinstr helper function using the guest_state_{enter,exit}_irqoff() helpers. These perform all the lockdep/RCU/tracing manipulation necessary, but as sie64a() does not enable/disable interrupts, we must do this explicitly with the non-instrumented arch_local_irq_{enable,disable}() helpers: guest_state_enter_irqoff() arch_local_irq_enable(); sie64a(...); arch_local_irq_disable(); guest_state_exit_irqoff(); [ajd@linux.ibm.com: rebase, fix commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20250708092742.104309-3-ajd@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20250708092742.104309-3-ajd@linux.ibm.com>
2025-06-17s390: Explicitly include <linux/export.h>Heiko Carstens
Explicitly include <linux/export.h> in files which contain an EXPORT_SYMBOL(). See commit a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1") for more details. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-05KVM: s390: rename PROT_NONE to PROT_TYPE_DUMMYLorenzo Stoakes
The enum type prot_type declared in arch/s390/kvm/gaccess.c declares an unfortunate identifier within it - PROT_NONE. This clashes with the protection bit define from the uapi for mmap() declared in include/uapi/asm-generic/mman-common.h, which is indeed what those casually reading this code would assume this to refer to. This means that any changes which subsequently alter headers in any way which results in the uapi header being imported here will cause build errors. Resolve the issue by renaming PROT_NONE to PROT_TYPE_DUMMY. Link: https://lkml.kernel.org/r/20250519145657.178365-1-lorenzo.stoakes@oracle.com Fixes: b3cefd6bf16e ("KVM: s390: Pass initialized arg even if unused") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Suggested-by: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@kuka.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202505140943.IgHDa9s7-lkp@intel.com/ Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: Ignacio Moreno Gonzalez <Ignacio.MorenoGonzalez@kuka.com> Acked-by: Yang Shi <yang@os.amperecomputing.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: <stable@vger.kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: James Houghton <jthoughton@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-28KVM: s390: Simplify and move pv codeClaudio Imbrenda
All functions in kvm/gmap.c fit better in kvm/pv.c instead. Move and rename them appropriately, then delete the now empty kvm/gmap.c and kvm/gmap.h. Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20250528095502.226213-5-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250528095502.226213-5-imbrenda@linux.ibm.com>
2025-05-28KVM: s390: Refactor and split some gmap helpersClaudio Imbrenda
Refactor some gmap functions; move the implementation into a separate file with only helper functions. The new helper functions work on vm addresses, leaving all gmap logic in the gmap functions, which mostly become just wrappers. The whole gmap handling is going to be moved inside KVM soon, but the helper functions need to touch core mm functions, and thus need to stay in the core of kernel. Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20250528095502.226213-4-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250528095502.226213-4-imbrenda@linux.ibm.com>
2025-05-28KVM: s390: Remove unneeded srcu lockClaudio Imbrenda
All paths leading to handle_essa() already hold the kvm->srcu. Remove unneeded srcu locking from handle_essa(). Add lockdep assertion to make sure we will always be holding kvm->srcu when entering handle_essa(). Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Link: https://lore.kernel.org/r/20250528095502.226213-3-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250528095502.226213-3-imbrenda@linux.ibm.com>
2025-05-28s390: Remove unneeded includesClaudio Imbrenda
Many files don't need to include asm/tlb.h or asm/gmap.h. On the other hand, asm/tlb.h does need to include asm/gmap.h. Remove all unneeded includes so that asm/tlb.h is not directly used by s390 arch code anymore. Remove asm/gmap.h from a few other files as well, so that now only KVM code, mm/gmap.c, and asm/tlb.h include it. Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20250528095502.226213-2-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250528095502.226213-2-imbrenda@linux.ibm.com>
2025-04-08Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "ARM: - Rework heuristics for resolving the fault IPA (HPFAR_EL2 v. re-walk stage-1 page tables) to align with the architecture. This avoids possibly taking an SEA at EL2 on the page table walk or using an architecturally UNKNOWN fault IPA - Use acquire/release semantics in the KVM FF-A proxy to avoid reading a stale value for the FF-A version - Fix KVM guest driver to match PV CPUID hypercall ABI - Use Inner Shareable Normal Write-Back mappings at stage-1 in KVM selftests, which is the only memory type for which atomic instructions are architecturally guaranteed to work s390: - Don't use %pK for debug printing and tracepoints x86: - Use a separate subclass when acquiring KVM's per-CPU posted interrupts wakeup lock in the scheduled out path, i.e. when adding a vCPU on the list of vCPUs to wake, to workaround a false positive deadlock. The schedule out code runs with a scheduler lock that the wakeup handler takes in the opposite order; but it does so with IRQs disabled and cannot run concurrently with a wakeup - Explicitly zero-initialize on-stack CPUID unions - Allow building irqbypass.ko as as module when kvm.ko is a module - Wrap relatively expensive sanity check with KVM_PROVE_MMU - Acquire SRCU in KVM_GET_MP_STATE to protect guest memory accesses selftests: - Add more scenarios to the MONITOR/MWAIT test - Add option to rseq test to override /dev/cpu_dma_latency - Bring list of exit reasons up to date - Cleanup Makefile to list once tests that are valid on all architectures Other: - Documentation fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (26 commits) KVM: arm64: Use acquire/release to communicate FF-A version negotiation KVM: arm64: selftests: Explicitly set the page attrs to Inner-Shareable KVM: arm64: selftests: Introduce and use hardware-definition macros KVM: VMX: Use separate subclasses for PI wakeup lock to squash false positive KVM: VMX: Assert that IRQs are disabled when putting vCPU on PI wakeup list KVM: x86: Explicitly zero-initialize on-stack CPUID unions KVM: Allow building irqbypass.ko as as module when kvm.ko is a module KVM: x86/mmu: Wrap sanity check on number of TDP MMU pages with KVM_PROVE_MMU KVM: selftests: Add option to rseq test to override /dev/cpu_dma_latency KVM: x86: Acquire SRCU in KVM_GET_MP_STATE to protect guest memory accesses Documentation: kvm: remove KVM_CAP_MIPS_TE Documentation: kvm: organize capabilities in the right section Documentation: kvm: fix some definition lists Documentation: kvm: drop "Capability" heading from capabilities Documentation: kvm: give correct name for KVM_CAP_SPAPR_MULTITCE Documentation: KVM: KVM_GET_SUPPORTED_CPUID now exposes TSC_DEADLINE selftests: kvm: list once tests that are valid on all architectures selftests: kvm: bring list of exit reasons up to date selftests: kvm: revamp MONITOR/MWAIT tests KVM: arm64: Don't translate FAR if invalid/unsafe ...
2025-03-31Merge tag 'kvm-s390-next-6.15-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD Pointer print format fixes
2025-03-29Merge tag 's390-6.15-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add sorting of mcount locations at build time - Rework uaccess functions with C exception handling to shorten inline assembly size and enable full inlining. This yields near-optimal code for small constant copies with a ~40kb kernel size increase - Add support for a configurable STRICT_MM_TYPECHECKS which allows to generate better code, but also allows to have type checking for debug builds - Optimize get_lowcore() for common callers with alternatives that nearly revert to the pre-relocated lowcore code, while also slightly reducing syscall entry and exit time - Convert MACHINE_HAS_* checks for single facility tests into cpu_has_* style macros that call test_facility(), and for features with additional conditions, add a new ALT_TYPE_FEATURE alternative to provide a static branch via alternative patching. Also, move machine feature detection to the decompressor for early patching and add debugging functionality to easily show which alternatives are patched - Add exception table support to early boot / startup code to get rid of the open coded exception handling - Use asm_inline for all inline assemblies with EX_TABLE or ALTERNATIVE to ensure correct inlining and unrolling decisions - Remove 2k page table leftovers now that s390 has been switched to always allocate 4k page tables - Split kfence pool into 4k mappings in arch_kfence_init_pool() and remove the architecture-specific kfence_split_mapping() - Use READ_ONCE_NOCHECK() in regs_get_kernel_stack_nth() to silence spurious KASAN warnings from opportunistic ftrace argument tracing - Force __atomic_add_const() variants on s390 to always return void, ensuring compile errors for improper usage - Remove s390's ioremap_wt() and pgprot_writethrough() due to mismatched semantics and lack of known users, relying on asm-generic fallbacks - Signal eventfd in vfio-ap to notify userspace when the guest AP configuration changes, including during mdev removal - Convert mdev_types from an array to a pointer in vfio-ccw and vfio-ap drivers to avoid fake flex array confusion - Cleanup trap code - Remove references to the outdated linux390@de.ibm.com address - Other various small fixes and improvements all over the code * tag 's390-6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (78 commits) s390: Use inline qualifier for all EX_TABLE and ALTERNATIVE inline assemblies s390/kfence: Split kfence pool into 4k mappings in arch_kfence_init_pool() s390/ptrace: Avoid KASAN false positives in regs_get_kernel_stack_nth() s390/boot: Ignore vmlinux.map s390/sysctl: Remove "vm/allocate_pgste" sysctl s390: Remove 2k vs 4k page table leftovers s390/tlb: Use mm_has_pgste() instead of mm_alloc_pgste() s390/lowcore: Use lghi instead llilh to clear register s390/syscall: Merge __do_syscall() and do_syscall() s390/spinlock: Implement SPINLOCK_LOCKVAL with inline assembly s390/smp: Implement raw_smp_processor_id() with inline assembly s390/current: Implement current with inline assembly s390/lowcore: Use inline qualifier for get_lowcore() inline assembly s390: Move s390 sysctls into their own file under arch/s390 s390/syscall: Simplify syscall_get_arguments() s390/vfio-ap: Notify userspace that guest's AP config changed when mdev removed s390: Remove ioremap_wt() and pgprot_writethrough() s390/mm: Add configurable STRICT_MM_TYPECHECKS s390/mm: Convert pgste_val() into function s390/mm: Convert pgprot_val() into function ...
2025-03-26Merge tag 'iommu-updates-v6.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux Pull iommu updates from Joerg Roedel: "Core iommufd dependencies from Jason: - Change the iommufd fault handle into an always present hwpt handle in the domain - Give iommufd its own SW_MSI implementation along with some IRQ layer rework - Improvements to the handle attach API Core fixes for probe-issues from Robin Intel VT-d changes: - Checking for SVA support in domain allocation and attach paths - Move PCI ATS and PRI configuration into probe paths - Fix a pentential hang on reboot -f - Miscellaneous cleanups AMD-Vi changes: - Support for up to 2k IRQs per PCI device function - Set of smaller fixes ARM-SMMU changes: - SMMUv2 devicetree binding updates for Qualcomm implementations (QCS8300 GPU and MSM8937) - Clean up SMMUv2 runtime PM implementation to help with wider rework of pm_runtime_put_autosuspend() Rockchip driver changes: - Driver adjustments for recent DT probing changes S390 IOMMU changes: - Support for IOMMU passthrough Apple Dart changes: - Driver adjustments to meet ISP device requirements - Null-ptr deref fix - Disable subpage protection for DART 1" * tag 'iommu-updates-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (54 commits) iommu/vt-d: Fix possible circular locking dependency iommu/vt-d: Don't clobber posted vCPU IRTE when host IRQ affinity changes iommu/vt-d: Put IRTE back into posted MSI mode if vCPU posting is disabled iommu: apple-dart: fix potential null pointer deref iommu/rockchip: Retire global dma_dev workaround iommu/rockchip: Register in a sensible order iommu/rockchip: Allocate per-device data sensibly iommu/mediatek-v1: Support COMPILE_TEST iommu/amd: Enable support for up to 2K interrupts per function iommu/amd: Rename DTE_INTTABLEN* and MAX_IRQS_PER_TABLE macro iommu/amd: Replace slab cache allocator with page allocator iommu/amd: Introduce generic function to set multibit feature value iommu: Don't warn prematurely about dodgy probes iommu/arm-smmu: Set rpm auto_suspend once during probe dt-bindings: arm-smmu: Document QCS8300 GPU SMMU iommu: Get DT/ACPI parsing into the proper probe path iommu: Keep dev->iommu state consistent iommu: Resolve ops in iommu_init_device() iommu: Handle race with default domain setup iommu: Unexport iommu_fwspec_free() ...
2025-03-25Merge tag 'timers-cleanups-2025-03-23' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer cleanups from Thomas Gleixner: "A treewide hrtimer timer cleanup hrtimers are initialized with hrtimer_init() and a subsequent store to the callback pointer. This turned out to be suboptimal for the upcoming Rust integration and is obviously a silly implementation to begin with. This cleanup replaces the hrtimer_init(T); T->function = cb; sequence with hrtimer_setup(T, cb); The conversion was done with Coccinelle and a few manual fixups. Once the conversion has completely landed in mainline, hrtimer_init() will be removed and the hrtimer::function becomes a private member" * tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits) wifi: rt2x00: Switch to use hrtimer_update_function() io_uring: Use helper function hrtimer_update_function() serial: xilinx_uartps: Use helper function hrtimer_update_function() ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup() RDMA: Switch to use hrtimer_setup() virtio: mem: Switch to use hrtimer_setup() drm/vmwgfx: Switch to use hrtimer_setup() drm/xe/oa: Switch to use hrtimer_setup() drm/vkms: Switch to use hrtimer_setup() drm/msm: Switch to use hrtimer_setup() drm/i915/request: Switch to use hrtimer_setup() drm/i915/uncore: Switch to use hrtimer_setup() drm/i915/pmu: Switch to use hrtimer_setup() drm/i915/perf: Switch to use hrtimer_setup() drm/i915/gvt: Switch to use hrtimer_setup() drm/i915/huc: Switch to use hrtimer_setup() drm/amdgpu: Switch to use hrtimer_setup() stm class: heartbeat: Switch to use hrtimer_setup() i2c: Switch to use hrtimer_setup() iio: Switch to use hrtimer_setup() ...
2025-03-17KVM: s390: Don't use %pK through debug printingThomas Weißschuh
Restricted pointers ("%pK") are only meant to be used when directly printing to a file from task context. Otherwise it can unintentionally expose security sensitive, raw pointer values. Use regular pointer formatting instead. Link: https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Link: https://lore.kernel.org/r/20250217-restricted-pointers-s390-v1-2-0e4ace75d8aa@linutronix.de Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20250217-restricted-pointers-s390-v1-2-0e4ace75d8aa@linutronix.de>
2025-03-17KVM: s390: Don't use %pK through tracepointsThomas Weißschuh
Restricted pointers ("%pK") are not meant to be used through TP_format(). It can unintentionally expose security sensitive, raw pointer values. Use regular pointer formatting instead. Link: https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Link: https://lore.kernel.org/r/20250217-restricted-pointers-s390-v1-1-0e4ace75d8aa@linutronix.de Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20250217-restricted-pointers-s390-v1-1-0e4ace75d8aa@linutronix.de>
2025-03-14KVM: s390: pv: fix race when making a page secureClaudio Imbrenda
Holding the pte lock for the page that is being converted to secure is needed to avoid races. A previous commit removed the locking, which caused issues. Fix by locking the pte again. Fixes: 5cbe24350b7d ("KVM: s390: move pv gmap functions into kvm") Reported-by: David Hildenbrand <david@redhat.com> Tested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> [david@redhat.com: replace use of get_locked_pte() with folio_walk_start()] Link: https://lore.kernel.org/r/20250312184912.269414-2-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250312184912.269414-2-imbrenda@linux.ibm.com>
2025-03-04s390/asm-offsets: Rename __LC_PGM_INT_CODEHeiko Carstens
Avoid confusion and rename __LC_PGM_INT_CODE since it correlates to the pgm_code member of struct lowcore, and not the pgm_int_code member. 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>
2025-03-04s390/kvm: Convert MACHINE_HAS_ESOP to machine_has_esop()Heiko Carstens
Use static branch(es) to implement and use machine_has_esop() instead of a runtime check via MACHINE_HAS_ESOP. 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>
2025-03-04s390/tlb: Convert MACHINE_HAS_TLB_GUEST to machine_has_tlb_guest()Heiko Carstens
Use static branch(es) to implement and use machine_has_tlb_guest() instead of a runtime check via MACHINE_HAS_TLB_GUEST. Also add sclp_early_detect_machine_features() in order to allow for feature detection from the decompressor. 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>
2025-03-04s390/cpufeature: Convert MACHINE_HAS_GS to cpu_has_gs()Heiko Carstens
Convert MACHINE_HAS_... to cpu_has_...() which uses test_facility() instead of testing the machine_flags lowcore member if the feature is present. test_facility() generates better code since it results in a static branch without accessing memory. The branch is patched via alternatives by the decompressor depending on the availability of the required facility. 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>
2025-02-21iommu/s390: handle IOAT registration based on domainMatthew Rosato
At this point, the dma_table is really a property of the s390-iommu domain. Rather than checking its contents elsewhere in the codebase, move the code that registers the table with firmware into s390-iommu and make a decision what to register with firmware based upon the type of domain in use for the device in question. Tested-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20250212213418.182902-4-mjrosato@linux.ibm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2025-02-18KVM: s390: Switch to use hrtimer_setup()Nam Cao
hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Patch was created by using Coccinelle. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/all/637865c62963fb8cddf6c4368ca12434988a8c27.1738746821.git.namcao@linutronix.de
2025-01-31KVM: s390: remove the last user of page->indexClaudio Imbrenda
Shadow page tables use page->index to keep the g2 address of the guest page table being shadowed. Instead of keeping the information in page->index, split the address and smear it over the 16-bit softbits areas of 4 PGSTEs. This removes the last s390 user of page->index. Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-16-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-16-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: move gmap_shadow_pgt_lookup() into kvmClaudio Imbrenda
Move gmap_shadow_pgt_lookup() from mm/gmap.c into kvm/gaccess.c . Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-13-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-13-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: move some gmap shadowing functions away from mm/gmap.cClaudio Imbrenda
Move some gmap shadowing functions from mm/gmap.c to kvm/kvm-s390.c and the newly created kvm/gmap-vsie.c This is a step toward removing gmap from mm. Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-10-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-10-imbrenda@linux.ibm.com>
2025-01-31KVM: s390: get rid of gmap_translate()Claudio Imbrenda
Add gpa_to_hva(), which uses memslots, and use it to replace all uses of gmap_translate(). Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Link: https://lore.kernel.org/r/20250123144627.312456-9-imbrenda@linux.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20250123144627.312456-9-imbrenda@linux.ibm.com>