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2025-03-20net: ti: icssg-prueth: Add lock to statsMD Danish Anwar
Currently the API emac_update_hardware_stats() reads different ICSSG stats without any lock protection. This API gets called by .ndo_get_stats64() which is only under RCU protection and nothing else. Add lock to this API so that the reading of statistics happens during lock. Fixes: c1e10d5dc7a1 ("net: ti: icssg-prueth: Add ICSSG Stats") Signed-off-by: MD Danish Anwar <danishanwar@ti.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250314102721.1394366-1-danishanwar@ti.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20net: atm: fix use after free in lec_send()Dan Carpenter
The ->send() operation frees skb so save the length before calling ->send() to avoid a use after free. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/c751531d-4af4-42fe-affe-6104b34b791d@stanley.mountain Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-20fs: tidy up do_sys_openat2() with likely/unlikelyMateusz Guzik
Otherwise gcc 13 generates conditional forward jumps (aka branch mispredict by default) for build_open_flags() being succesfull. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250320092331.1921700-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-20Merge branch 'slab/for-6.15/kfree_rcu_tiny' into slab/for-nextVlastimil Babka
Merge the slab feature branch kfree_rcu_tiny for 6.15: - Move the TINY_RCU kvfree_rcu() implementation from RCU to SLAB subsystem and cleanup its integration.
2025-03-20cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()Yujun Dong
In architectures that use the polling bit, current_clr_polling() employs smp_mb() to ensure that the clearing of the polling bit is visible to other cores before checking TIF_NEED_RESCHED. However, smp_mb() can be costly. Given that clear_bit() is an atomic operation, replacing smp_mb() with smp_mb__after_atomic() is appropriate. Many architectures implement smp_mb__after_atomic() as a lighter-weight barrier compared to smp_mb(), leading to performance improvements. For instance, on x86, smp_mb__after_atomic() is a no-op. This change eliminates a smp_mb() instruction in the cpuidle wake-up path, saving several CPU cycles and thereby reducing wake-up latency. Architectures that do not use the polling bit will retain the original smp_mb() behavior to ensure that existing dependencies remain unaffected. Signed-off-by: Yujun Dong <yujundong@pascal-lab.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20241230141624.155356-1-yujundong@pascal-lab.net
2025-03-20fs: reduce work in fdget_pos()Mateusz Guzik
1. predict the file was found 2. explicitly compare the ref to "one", ignoring the dead zone The latter arguably improves the behavior to begin with. Suppose the count turned bad -- the previously used ref routine is going to check for it and return 0, indicating the count does not necessitate taking ->f_pos_lock. But there very well may be several users. i.e. not paying for special-casing the dead zone improves semantics. While here spell out each condition in a dedicated if statement. This has no effect on generated code. Sizes are as follows (in bytes; gcc 13, x86-64): stock: 321 likely(): 298 likely()+ref: 280 Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250319215801.1870660-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-20RISC-V: KVM: Optimize comments in kvm_riscv_vcpu_isa_disable_allowedChao Du
The comments for EXT_SVADE are a bit confusing. Clarify it. Signed-off-by: Chao Du <duchao@eswincomputing.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20250221025929.31678-1-duchao@eswincomputing.com Signed-off-by: Anup Patel <anup@brainfault.org>
2025-03-19xsk: fix an integer overflow in xp_create_and_assign_umem()Gavrilov Ilia
Since the i and pool->chunk_size variables are of type 'u32', their product can wrap around and then be cast to 'u64'. This can lead to two different XDP buffers pointing to the same memory area. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 94033cd8e73b ("xsk: Optimize for aligned case") Cc: stable@vger.kernel.org Signed-off-by: Ilia Gavrilov <Ilia.Gavrilov@infotecs.ru> Link: https://patch.msgid.link/20250313085007.3116044-1-Ilia.Gavrilov@infotecs.ru Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-19Merge branch 'kvm-arm64/pmu-fixes' into kvmarm/nextOliver Upton
* kvm-arm64/pmu-fixes: : vPMU fixes for 6.15 courtesy of Akihiko Odaki : : Various fixes to KVM's vPMU implementation, notably ensuring : userspace-directed changes to the PMCs are reflected in the backing perf : events. KVM: arm64: PMU: Reload when resetting KVM: arm64: PMU: Reload when user modifies registers KVM: arm64: PMU: Fix SET_ONE_REG for vPMC regs KVM: arm64: PMU: Assume PMU presence in pmu-emul.c KVM: arm64: PMU: Set raw values from user to PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/pkvm-6.15' into kvmarm/nextOliver Upton
* kvm-arm64/pkvm-6.15: : pKVM updates for 6.15 : : - SecPageTable stats for stage-2 table pages allocated by the protected : hypervisor (Vincent Donnefort) : : - HCRX_EL2 trap + vCPU initialization fixes for pKVM (Fuad Tabba) KVM: arm64: Create each pKVM hyp vcpu after its corresponding host vcpu KVM: arm64: Factor out pKVM hyp vcpu creation to separate function KVM: arm64: Initialize HCRX_EL2 traps in pKVM KVM: arm64: Factor out setting HCRX_EL2 traps into separate function KVM: arm64: Count pKVM stage-2 usage in secondary pagetable stats KVM: arm64: Distinct pKVM teardown memcache for stage-2 KVM: arm64: Add flags to kvm_hyp_memcache Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/writable-midr' into kvmarm/nextOliver Upton
* kvm-arm64/writable-midr: : Writable implementation ID registers, courtesy of Sebastian Ott : : Introduce a new capability that allows userspace to set the : ID registers that identify a CPU implementation: MIDR_EL1, REVIDR_EL1, : and AIDR_EL1. Also plug a hole in KVM's trap configuration where : SMIDR_EL1 was readable at EL1, despite the fact that KVM does not : support SME. KVM: arm64: Fix documentation for KVM_CAP_ARM_WRITABLE_IMP_ID_REGS KVM: arm64: Copy MIDR_EL1 into hyp VM when it is writable KVM: arm64: Copy guest CTR_EL0 into hyp VM KVM: selftests: arm64: Test writes to MIDR,REVIDR,AIDR KVM: arm64: Allow userspace to change the implementation ID registers KVM: arm64: Load VPIDR_EL2 with the VM's MIDR_EL1 value KVM: arm64: Maintain per-VM copy of implementation ID regs KVM: arm64: Set HCR_EL2.TID1 unconditionally Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/pmuv3-asahi' into kvmarm/nextOliver Upton
* kvm-arm64/pmuv3-asahi: : Support PMUv3 for KVM guests on Apple silicon : : Take advantage of some IMPLEMENTATION DEFINED traps available on Apple : parts to trap-and-emulate the PMUv3 registers on behalf of a KVM guest. : Constrain the vPMU to a cycle counter and single event counter, as the : Apple PMU has events that cannot be counted on every counter. : : There is a small new interface between the ARM PMU driver and KVM, where : the PMU driver owns the PMUv3 -> hardware event mappings. arm64: Enable IMP DEF PMUv3 traps on Apple M* KVM: arm64: Provide 1 event counter on IMPDEF hardware drivers/perf: apple_m1: Provide helper for mapping PMUv3 events KVM: arm64: Remap PMUv3 events onto hardware KVM: arm64: Advertise PMUv3 if IMPDEF traps are present KVM: arm64: Compute synthetic sysreg ESR for Apple PMUv3 traps KVM: arm64: Move PMUVer filtering into KVM code KVM: arm64: Use guard() to cleanup usage of arm_pmus_lock KVM: arm64: Drop kvm_arm_pmu_available static key KVM: arm64: Use a cpucap to determine if system supports FEAT_PMUv3 KVM: arm64: Always support SW_INCR PMU event KVM: arm64: Compute PMCEID from arm_pmu's event bitmaps drivers/perf: apple_m1: Support host/guest event filtering drivers/perf: apple_m1: Refactor event select/filter configuration Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/pv-cpuid' into kvmarm/nextOliver Upton
* kvm-arm64/pv-cpuid: : Paravirtualized implementation ID, courtesy of Shameer Kolothum : : Big-little has historically been a pain in the ass to virtualize. The : implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim : of vCPU scheduling. This can be particularly annoying when the guest : needs to know the underlying implementation to mitigate errata. : : "Hyperscalers" face a similar scheduling problem, where VMs may freely : migrate between hosts in a pool of heterogenous hardware. And yes, our : server-class friends are equally riddled with errata too. : : In absence of an architected solution to this wart on the ecosystem, : introduce support for paravirtualizing the implementation exposed : to a VM, allowing the VMM to describe the pool of implementations that a : VM may be exposed to due to scheduling/migration. : : Userspace is expected to intercept and handle these hypercalls using the : SMCCC filter UAPI, should it choose to do so. smccc: kvm_guest: Fix kernel builds for 32 bit arm KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2 smccc/kvm_guest: Enable errata based on implementation CPUs arm64: Make  _midr_in_range_list() an exported function KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2 KVM: arm64: Specify hypercall ABI for retrieving target implementations arm64: Modify _midr_range() functions to read MIDR/REVIDR internally Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/nv-idregs' into kvmarm/nextOliver Upton
* kvm-arm64/nv-idregs: : Changes to exposure of NV features, courtesy of Marc Zyngier : : Apply NV-specific feature restrictions at reset rather than at the point : of KVM_RUN. This makes the true feature set visible to userspace, a : necessary step towards save/restore support or NV VMs. : : Add an additional vCPU feature flag for selecting the E2H0 flavor of NV, : such that the VHE-ness of the VM can be applied to the feature set. KVM: arm64: selftests: Test that TGRAN*_2 fields are writable KVM: arm64: Allow userspace to write ID_AA64MMFR0_EL1.TGRAN*_2 KVM: arm64: Advertise FEAT_ECV when possible KVM: arm64: Make ID_AA64MMFR4_EL1.NV_frac writable KVM: arm64: Allow userspace to limit NV support to nVHE KVM: arm64: Move NV-specific capping to idreg sanitisation KVM: arm64: Enforce NV limits on a per-idregs basis KVM: arm64: Make ID_REG_LIMIT_FIELD_ENUM() more widely available KVM: arm64: Consolidate idreg callbacks KVM: arm64: Advertise NV2 in the boot messages KVM: arm64: Mark HCR.EL2.{NV*,AT} RES0 when ID_AA64MMFR4_EL1.NV_frac is 0 KVM: arm64: Mark HCR.EL2.E2H RES0 when ID_AA64MMFR1_EL1.VH is zero KVM: arm64: Hide ID_AA64MMFR2_EL1.NV from guest and userspace arm64: cpufeature: Handle NV_frac as a synonym of NV2 Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/nv-vgic' into kvmarm/nextOliver Upton
* kvm-arm64/nv-vgic: : NV VGICv3 support, courtesy of Marc Zyngier : : Support for emulating the GIC hypervisor controls and managing shadow : VGICv3 state for the L1 hypervisor. As part of it, bring in support for : taking IRQs to the L1 and UAPI to manage the VGIC maintenance interrupt. KVM: arm64: nv: Fail KVM init if asking for NV without GICv3 KVM: arm64: nv: Allow userland to set VGIC maintenance IRQ KVM: arm64: nv: Fold GICv3 host trapping requirements into guest setup KVM: arm64: nv: Propagate used_lrs between L1 and L0 contexts KVM: arm64: nv: Request vPE doorbell upon nested ERET to L2 KVM: arm64: nv: Respect virtual HCR_EL2.TWx setting KVM: arm64: nv: Add Maintenance Interrupt emulation KVM: arm64: nv: Handle L2->L1 transition on interrupt injection KVM: arm64: nv: Nested GICv3 emulation KVM: arm64: nv: Sanitise ICH_HCR_EL2 accesses KVM: arm64: nv: Plumb handling of GICv3 EL2 accesses KVM: arm64: nv: Add ICH_*_EL2 registers to vpcu_sysreg KVM: arm64: nv: Load timer before the GIC arm64: sysreg: Add layout for ICH_MISR_EL2 arm64: sysreg: Add layout for ICH_VTR_EL2 arm64: sysreg: Add layout for ICH_HCR_EL2 Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19Merge branch 'kvm-arm64/misc' into kvmarm/nextOliver Upton
* kvm-arm64/misc: : Miscellaneous fixes/cleanups for KVM/arm64 : : - Avoid GICv4 vLPI configuration when confronted with user error : : - Only attempt vLPI configuration when the target routing is an MSI : : - Document ordering requirements to avoid aforementioned user error KVM: arm64: Tear down vGIC on failed vCPU creation KVM: arm64: Document ordering requirements for irqbypass KVM: arm64: vgic-v4: Fall back to software irqbypass if LPI not found KVM: arm64: vgic-v4: Only WARN for HW IRQ mismatch when unmapping vLPI KVM: arm64: vgic-v4: Only attempt vLPI mapping for actual MSIs Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-19sched/debug: Remove CONFIG_SCHED_DEBUGIngo Molnar
For more than a decade, CONFIG_SCHED_DEBUG=y has been enabled in all the major Linux distributions: /boot/config-6.11.0-19-generic:CONFIG_SCHED_DEBUG=y The reason is that while originally CONFIG_SCHED_DEBUG started out as a debugging feature, over the years (decades ...) it has grown various bits of statistics, instrumentation and control knobs that are useful for sysadmin and general software development purposes as well. But within the kernel we still pretend that there's a choice, and sometimes code that is seemingly 'debug only' creates overhead that should be optimized in reality. So make it all official and make CONFIG_SCHED_DEBUG unconditional. Now that all uses of CONFIG_SCHED_DEBUG are removed from the code by previous patches, remove the Kconfig option as well. Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317104257.3496611-6-mingo@kernel.org
2025-03-19sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config filesIngo Molnar
We leave most of the defconfigs alone (there's over 70 of them), but let's remove CONFIG_SCHED_DEBUG from the scheduler self-test Kconfig files. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/Z9szt3MpQmQ56TRd@gmail.com
2025-03-19sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from ↵Ingo Molnar
documentation Since it's enabled unconditionally now, remove all references to it. (Left out languages I cannot read.) Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317104257.3496611-5-mingo@kernel.org
2025-03-19sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditionalIngo Molnar
All the big Linux distros enable CONFIG_SCHED_DEBUG, because the various features it provides help not just with kernel development, but with system administration and user-space software development as well. Reflect this reality and enable this functionality unconditionally. Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317104257.3496611-4-mingo@kernel.org
2025-03-19sched/debug: Make 'const_debug' tunables unconditional __read_mostlyIngo Molnar
With CONFIG_SCHED_DEBUG becoming unconditional, remove the extra 'const_debug' indirection towards __read_mostly. Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317104257.3496611-3-mingo@kernel.org
2025-03-19sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()Ingo Molnar
The scheduler has this special SCHED_WARN() facility that depends on CONFIG_SCHED_DEBUG. Since CONFIG_SCHED_DEBUG is getting removed, convert SCHED_WARN() to WARN_ON_ONCE(). Note that the warning output isn't 100% equivalent: #define SCHED_WARN_ON(x) WARN_ONCE(x, #x) Because SCHED_WARN_ON() would output the 'x' condition as well, while WARN_ONCE() will only show a backtrace. Hopefully these are rare enough to not really matter. If it does, we should probably introduce a new WARN_ON() variant that outputs the condition in stringified form, or improve WARN_ON() itself. Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317104257.3496611-2-mingo@kernel.org
2025-03-19x86/mm: Only do broadcast flush from reclaim if pages were unmappedRik van Riel
Track whether pages were unmapped from any MM (even ones with a currently empty mm_cpumask) by the reclaim code, to figure out whether or not broadcast TLB flush should be done when reclaim finishes. The reason any MM must be tracked, and not only ones contributing to the tlbbatch cpumask, is that broadcast ASIDs are expected to be kept up to date even on CPUs where the MM is not currently active. This change allows reclaim to avoid doing TLB flushes when only clean page cache pages and/or slab memory were reclaimed, which is fairly common. ( This is a simpler alternative to the code that was in my INVLPGB series before, and it seems to capture most of the benefit due to how common it is to reclaim only page cache. ) Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250319132520.6b10ad90@fangorn
2025-03-19perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM onesSohil Mehta
Introduce a name for an old Pentium 4 model and replace the x86_model checks with VFM ones. This gets rid of one of the last remaining Intel-specific x86_model checks. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250318223828.2945651-3-sohil.mehta@intel.com
2025-03-19perf/x86/intel, x86/cpu: Simplify Intel PMU initializationSohil Mehta
Architectural Perfmon was introduced on the Family 6 "Core" processors starting with Yonah. Processors before Yonah need their own customized PMU initialization. p6_pmu_init() is expected to provide that initialization for early Family 6 processors. But, currently, it could get called for any Family 6 processor if the architectural perfmon feature is disabled on that processor. To simplify, restrict the P6 PMU initialization to early Family 6 processors that do not have architectural perfmon support and truly need the special handling. As a result, the "unsupported" console print becomes practically unreachable because all the released P6 processors are covered by the switch cases. Move the console print to a common location where it can cover all modern processors (including Family >15) that may not have architectural perfmon support enumerated. Also, use this opportunity to get rid of the unnecessary switch cases in P6 initialization. Only the Pentium Pro processor needs a quirk, and the rest of the processors do not need any special handling. The gaps in the case numbers are only due to no processor with those model numbers being released. Use decimal numbers to represent Intel Family numbers. Also, convert one of the last few Intel x86_model comparisons to a VFM-based one. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250318223828.2945651-2-sohil.mehta@intel.com
2025-03-19rseq/selftests: Fix namespace collision with rseq UAPI headerMichael Jeanson
When the rseq UAPI header is included, 'union rseq' clashes with 'struct rseq'. It's not the case in the rseq selftests but it does break the KVM selftests that also include this file. Rename 'union rseq' to 'union rseq_tls' to fix this. Fixes: e6644c967d3c ("rseq/selftests: Ensure the rseq ABI TLS is actually 1024 bytes") Reported-by: Mark Brown <broonie@kernel.org> Signed-off-by: Michael Jeanson <mjeanson@efficios.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/r/20250319202144.1141542-1-mjeanson@efficios.com
2025-03-19MAINTAINERS: Add a secondary maintainer for bluefield_edacDavid Thompson
Add David as a secondary maintainer. [ bp: Rewrite commit message. ] Signed-off-by: David Thompson <davthompson@nvidia.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20250319181630.2673-1-davthompson@nvidia.com
2025-03-19x86/crc: drop the avx10_256 functions and rename avx10_512 to avx512Eric Biggers
Intel made a late change to the AVX10 specification that removes support for a 256-bit maximum vector length and enumeration of the maximum vector length. AVX10 will imply a maximum vector length of 512 bits. I.e. there won't be any such thing as AVX10/256 or AVX10/512; there will just be AVX10, and it will essentially just consolidate AVX512 features. As a result of this new development, my strategy of providing both *_avx10_256 and *_avx10_512 functions didn't turn out to be that useful. The only remaining motivation for the 256-bit AVX512 / AVX10 functions is to avoid downclocking on older Intel CPUs. But I already wrote *_avx2 code too (primarily to support CPUs without AVX512), which performs almost as well as *_avx10_256. So we should just use that. Therefore, remove the *_avx10_256 CRC functions, and rename the *_avx10_512 CRC functions to *_avx512. Make Ice Lake and Tiger Lake use the *_avx2 functions instead of *_avx10_256 which they previously used. Link: https://lore.kernel.org/r/20250319181316.91271-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2025-03-19Merge tag 'chinese-doc-6.15-rc1' of ↵Jonathan Corbet
gitolite.kernel.org:pub/scm/linux/kernel/git/alexs/linux into docs-mw Chinese translation docs for 6.15-rc1 This is the Chinese translation subtree for 6.15-rc1. It just includes few changes: - Chinese disclaimer change - add a new translation doc: snp-tdx-threat-model - fix a typo Above patches are tested by 'make htmldocs/pdfdocs' Signed-off-by: Alex Shi <alexs@kernel.org>
2025-03-19Merge tag 'for-net-2025-03-14' of ↵Paolo Abeni
git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth Luiz Augusto von Dentz says: ==================== bluetooth pull request for net: - hci_event: Fix connection regression between LE and non-LE adapters - Fix error code in chan_alloc_skb_cb() * tag 'for-net-2025-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth: Bluetooth: hci_event: Fix connection regression between LE and non-LE adapters Bluetooth: Fix error code in chan_alloc_skb_cb() ==================== Link: https://patch.msgid.link/20250314163847.110069-1-luiz.dentz@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-19Merge tag 'hwmon-fixes-for-v6.14-rc8/6.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging Pull hwmon fixes from Guenter Roeck: - Fix an entry in MAINTAINERS to avoid sending hwmon review requests to the i2c mailing list - Fix an out-of-bounds access in nct6775 driver * tag 'hwmon-fixes-for-v6.14-rc8/6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: hwmon: (nct6775-core) Fix out of bounds access for NCT679{8,9} MAINTAINERS: correct list and scope of LTC4286 HARDWARE MONITOR
2025-03-19net: stmmac: dwc-qos-eth: use devm_kzalloc() for AXI dataRussell King (Oracle)
Everywhere else in the driver uses devm_kzalloc() when allocating the AXI data, so there is no kfree() of this structure. However, dwc-qos-eth uses kzalloc(), which leads to this memory being leaked. Switch to use devm_kzalloc(). Fixes: d8256121a91a ("stmmac: adding new glue driver dwmac-dwc-qos-eth") Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/E1tsRyv-0064nU-O9@rmk-PC.armlinux.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-19gpu: host1x: Do not assume that a NULL domain means no DMA IOMMUJason Gunthorpe
Previously with tegra-smmu, even with CONFIG_IOMMU_DMA, the default domain could have been left as NULL. The NULL domain is specially recognized by host1x_iommu_attach() as meaning it is not the DMA domain and should be replaced with the special shared domain. This happened prior to the below commit because tegra-smmu was using the NULL domain to mean IDENTITY. Now that the domain is properly labled the test in DRM doesn't see NULL. Check for IDENTITY as well to enable the special domains. This is the same issue and basic fix as seen in commit fae6e669cdc5 ("drm/tegra: Do not assume that a NULL domain means no DMA IOMMU"). Fixes: c8cc2655cc6c ("iommu/tegra-smmu: Implement an IDENTITY domain") Reported-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt> Closes: https://lore.kernel.org/all/c6a6f114-3acd-4d56-a13b-b88978e927dc@tecnico.ulisboa.pt/ Tested-by: Diogo Ivo <diogo.ivo@tecnico.ulisboa.pt> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://patchwork.freedesktop.org/patch/msgid/0-v1-10dcc8ce3869+3a7-host1x_identity_jgg@nvidia.com
2025-03-19cgroup/rstat: avoid disabling irqs for O(num_cpu)Eric Dumazet
cgroup_rstat_flush_locked() grabs the irq safe cgroup_rstat_lock while iterating all possible cpus. It only drops the lock if there is scheduler or spin lock contention. If neither, then interrupts can be disabled for a long time. On large machines this can disable interrupts for a long enough time to drop network packets. On 400+ CPU machines I've seen interrupt disabled for over 40 msec. Prevent rstat from disabling interrupts while processing all possible cpus. Instead drop and reacquire cgroup_rstat_lock for each cpu. This approach was previously discussed in https://lore.kernel.org/lkml/ZBz%2FV5a7%2F6PZeM7S@slm.duckdns.org/, though this was in the context of an non-irq rstat spin lock. Benchmark this change with: 1) a single stat_reader process with 400 threads, each reading a test memcg's memory.stat repeatedly for 10 seconds. 2) 400 memory hog processes running in the test memcg and repeatedly charging memory until oom killed. Then they repeat charging and oom killing. v6.14-rc6 with CONFIG_IRQSOFF_TRACER with stat_reader and hogs, finds interrupts are disabled by rstat for 45341 usec: # => started at: _raw_spin_lock_irq # => ended at: cgroup_rstat_flush # # # _------=> CPU# # / _-----=> irqs-off/BH-disabled # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / _-=> migrate-disable # ||||| / delay # cmd pid |||||| time | caller # \ / |||||| \ | / stat_rea-96532 52d.... 0us*: _raw_spin_lock_irq stat_rea-96532 52d.... 45342us : cgroup_rstat_flush stat_rea-96532 52d.... 45342us : tracer_hardirqs_on <-cgroup_rstat_flush stat_rea-96532 52d.... 45343us : <stack trace> => memcg1_stat_format => memory_stat_format => memory_stat_show => seq_read_iter => vfs_read => ksys_read => do_syscall_64 => entry_SYSCALL_64_after_hwframe With this patch the CONFIG_IRQSOFF_TRACER doesn't find rstat to be the longest holder. The longest irqs-off holder has irqs disabled for 4142 usec, a huge reduction from previous 45341 usec rstat finding. Running stat_reader memory.stat reader for 10 seconds: - without memory hogs: 9.84M accesses => 12.7M accesses - with memory hogs: 9.46M accesses => 11.1M accesses The throughput of memory.stat access improves. The mode of memory.stat access latency after grouping by of 2 buckets: - without memory hogs: 64 usec => 16 usec - with memory hogs: 64 usec => 8 usec The memory.stat latency improves. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Greg Thelen <gthelen@google.com> Tested-by: Greg Thelen <gthelen@google.com> Acked-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-19selftests: drv-net: use defer in the ping testJakub Kicinski
Make sure the test cleans up after itself. The XDP off statements at the end of the test may not be reached. Fixes: 75cc19c8ff89 ("selftests: drv-net: add xdp cases for ping.py") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250312131040.660386-1-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-19RISC-V: KVM: Teardown riscv specific bits after kvm_exitAtish Patra
During a module removal, kvm_exit invokes arch specific disable call which disables AIA. However, we invoke aia_exit before kvm_exit resulting in the following warning. KVM kernel module can't be inserted afterwards due to inconsistent state of IRQ. [25469.031389] percpu IRQ 31 still enabled on CPU0! [25469.031732] WARNING: CPU: 3 PID: 943 at kernel/irq/manage.c:2476 __free_percpu_irq+0xa2/0x150 [25469.031804] Modules linked in: kvm(-) [25469.031848] CPU: 3 UID: 0 PID: 943 Comm: rmmod Not tainted 6.14.0-rc5-06947-g91c763118f47-dirty #2 [25469.031905] Hardware name: riscv-virtio,qemu (DT) [25469.031928] epc : __free_percpu_irq+0xa2/0x150 [25469.031976] ra : __free_percpu_irq+0xa2/0x150 [25469.032197] epc : ffffffff8007db1e ra : ffffffff8007db1e sp : ff2000000088bd50 [25469.032241] gp : ffffffff8131cef8 tp : ff60000080b96400 t0 : ff2000000088baf8 [25469.032285] t1 : fffffffffffffffc t2 : 5249207570637265 s0 : ff2000000088bd90 [25469.032329] s1 : ff60000098b21080 a0 : 037d527a15eb4f00 a1 : 037d527a15eb4f00 [25469.032372] a2 : 0000000000000023 a3 : 0000000000000001 a4 : ffffffff8122dbf8 [25469.032410] a5 : 0000000000000fff a6 : 0000000000000000 a7 : ffffffff8122dc10 [25469.032448] s2 : ff60000080c22eb0 s3 : 0000000200000022 s4 : 000000000000001f [25469.032488] s5 : ff60000080c22e00 s6 : ffffffff80c351c0 s7 : 0000000000000000 [25469.032582] s8 : 0000000000000003 s9 : 000055556b7fb490 s10: 00007ffff0e12fa0 [25469.032621] s11: 00007ffff0e13e9a t3 : ffffffff81354ac7 t4 : ffffffff81354ac7 [25469.032664] t5 : ffffffff81354ac8 t6 : ffffffff81354ac7 [25469.032698] status: 0000000200000100 badaddr: ffffffff8007db1e cause: 0000000000000003 [25469.032738] [<ffffffff8007db1e>] __free_percpu_irq+0xa2/0x150 [25469.032797] [<ffffffff8007dbfc>] free_percpu_irq+0x30/0x5e [25469.032856] [<ffffffff013a57dc>] kvm_riscv_aia_exit+0x40/0x42 [kvm] [25469.033947] [<ffffffff013b4e82>] cleanup_module+0x10/0x32 [kvm] [25469.035300] [<ffffffff8009b150>] __riscv_sys_delete_module+0x18e/0x1fc [25469.035374] [<ffffffff8000c1ca>] syscall_handler+0x3a/0x46 [25469.035456] [<ffffffff809ec9a4>] do_trap_ecall_u+0x72/0x134 [25469.035536] [<ffffffff809f5e18>] handle_exception+0x148/0x156 Invoke aia_exit and other arch specific cleanup functions after kvm_exit so that disable gets a chance to be called first before exit. Fixes: 54e43320c2ba ("RISC-V: KVM: Initial skeletal support for AIA") Fixes: eded6754f398 ("riscv: KVM: add basic support for host vs guest profiling") Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20250317-kvm_exit_fix-v1-1-aa5240c5dbd2@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2025-03-19Merge tag 'ata-6.14-final' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux Pull ata fix from Niklas Cassel: - Fix a regression on ATI AHCI controllers, where certain Samsung drives fails to be detected on a warm boot when LPM is enabled. LPM on ATI AHCI works fine with other drives. Likewise, the Samsung drives works fine with LPM with other AHI controllers. Thus, just like the weirdo ATA_QUIRK_NO_NCQ_ON_ATI quirk, add a new ATA_QUIRK_NO_LPM_ON_ATI quirk to disable LPM only on ATI AHCI controllers. * tag 'ata-6.14-final' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux: ata: libata-core: Add ATA_QUIRK_NO_LPM_ON_ATI for certain Samsung SSDs
2025-03-19pidfs: ensure that PIDFS_INFO_EXIT is availableChristian Brauner
When we currently create a pidfd we check that the task hasn't been reaped right before we create the pidfd. But it is of course possible that by the time we return the pidfd to userspace the task has already been reaped since we don't check again after having created a dentry for it. This was fine until now because that race was meaningless. But now that we provide PIDFD_INFO_EXIT it is a problem because it is possible that the kernel returns a reaped pidfd and it depends on the race whether PIDFD_INFO_EXIT information is available. This depends on if the task gets reaped before or after a dentry has been attached to struct pid. Make this consistent and only returned pidfds for reaped tasks if PIDFD_INFO_EXIT information is available. This is done by performing another check whether the task has been reaped right after we attached a dentry to struct pid. Since pidfs_exit() is called before struct pid's task linkage is removed the case where the task got reaped but a dentry was already attached to struct pid and exit information was recorded and published can be handled correctly. In that case we do return a pidfd for a reaped task like we would've before. Link: https://lore.kernel.org/r/20250316-kabel-fehden-66bdb6a83436@brauner Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-19Merge tag 'kvm-x86-xen-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM Xen changes for 6.15 - Don't write to the Xen hypercall page on MSR writes that are initiated by the host (userspace or KVM) to fix a class of bugs where KVM can write to guest memory at unexpected times, e.g. during vCPU creation if userspace has set the Xen hypercall MSR index to collide with an MSR that KVM emulates. - Restrict the Xen hypercall MSR indx to the unofficial synthetic range to reduce the set of possible collisions with MSRs that are emulated by KVM (collisions can still happen as KVM emulates Hyper-V MSRs, which also reside in the synthetic range). - Clean up and optimize KVM's handling of Xen MSR writes and xen_hvm_config. - Update Xen TSC leaves during CPUID emulation instead of modifying the CPUID entries when updating PV clocks, as there is no guarantee PV clocks will be updated between TSC frequency changes and CPUID emulation, and guest reads of Xen TSC should be rare, i.e. are not a hot path.
2025-03-19Merge tag 'kvm-x86-pvclock-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM PV clock changes for 6.15: - Don't take kvm->lock when iterating over vCPUs in the suspend notifier to fix a largely theoretical deadlock. - Use the vCPU's actual Xen PV clock information when starting the Xen timer, as the cached state in arch.hv_clock can be stale/bogus. - Fix a bug where KVM could bleed PVCLOCK_GUEST_STOPPED across different PV clocks. - Restrict PVCLOCK_GUEST_STOPPED to kvmclock, as KVM's suspend notifier only accounts for kvmclock, and there's no evidence that the flag is actually supported by Xen guests. - Clean up the per-vCPU "cache" of its reference pvclock, and instead only track the vCPU's TSC scaling (multipler+shift) metadata (which is moderately expensive to compute, and rarely changes for modern setups).
2025-03-19Merge tag 'kvm-x86-svm-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM SVM changes for 6.15 - Ensure the PSP driver is initialized when both the PSP and KVM modules are built-in (the initcall framework doesn't handle dependencies). - Use long-term pins when registering encrypted memory regions, so that the pages are migrated out of MIGRATE_CMA/ZONE_MOVABLE and don't lead to excessive fragmentation. - Add macros and helpers for setting GHCB return/error codes. - Add support for Idle HLT interception, which elides interception if the vCPU has a pending, unmasked virtual IRQ when HLT is executed. - Fix a bug in INVPCID emulation where KVM fails to check for a non-canonical address. - Don't attempt VMRUN for SEV-ES+ guests if the vCPU's VMSA is invalid, e.g. because the vCPU was "destroyed" via SNP's AP Creation hypercall. - Reject SNP AP Creation if the requested SEV features for the vCPU don't match the VM's configured set of features. - Misc cleanups
2025-03-19fs: predict not reaching the limit in alloc_empty_file()Mateusz Guzik
Eliminates a jump over a call to capable() in the common case. By default the limit is not even set, in which case the check can't even fail to begin with. It remains unset at least on Debian and Ubuntu. For this cases this can probably become a static branch instead. In the meantime tidy it up. I note the check separate from the bump makes the entire thing racy. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250319124923.1838719-1-mjguzik@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-19iomap: fix inline data on buffered readGao Xiang
Previously, iomap_readpage_iter() returning 0 would break out of the loops of iomap_readahead_iter(), which is what iomap_read_inline_data() relies on. However, commit d9dc477ff6a2 ("iomap: advance the iter directly on buffered read") changes this behavior without calling iomap_iter_advance(), which causes EROFS to get stuck in iomap_readpage_iter(). It seems iomap_iter_advance() cannot be called in iomap_read_inline_data() because of the iomap_write_begin() path, so handle this in iomap_readpage_iter() instead. Reported-and-tested-by: Bo Liu <liubo03@inspur.com> Fixes: d9dc477ff6a2 ("iomap: advance the iter directly on buffered read") Cc: Brian Foster <bfoster@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20250319085125.4039368-1-hsiangkao@linux.alibaba.com Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-19Merge tag 'kvm-x86-vmx-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM VMX changes for 6.15 - Fix a bug where KVM unnecessarily reads XFD_ERR from hardware and thus modifies the vCPU's XFD_ERR on a #NM due to CR0.TS=1. - Pass XFD_ERR as a psueo-payload when injecting #NM as a preparatory step for upcoming FRED virtualization support. - Decouple the EPT entry RWX protection bit macros from the EPT Violation bits as a general cleanup, and in anticipation of adding support for emulating Mode-Based Execution (MBEC). - Reject KVM_RUN if userspace manages to gain control and stuff invalid guest state while KVM is in the middle of emulating nested VM-Enter. - Add a macro to handle KVM's sanity checks on entry/exit VMCS control pairs in anticipation of adding sanity checks for secondary exit controls (the primary field is out of bits).
2025-03-19Merge tag 'kvm-x86-selftests-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM selftests changes for 6.15, part 2 - Fix a variety of flaws, bugs, and false failures/passes dirty_log_test, and improve its coverage by collecting all dirty entries on each iteration. - Fix a few minor bugs related to handling of stats FDs. - Add infrastructure to make vCPU and VM stats FDs available to tests by default (open the FDs during VM/vCPU creation). - Relax an assertion on the number of HLT exits in the xAPIC IPI test when running on a CPU that supports AMD's Idle HLT (which elides interception of HLT if a virtual IRQ is pending and unmasked). - Misc cleanups and fixes.
2025-03-19Merge tag 'kvm-x86-selftests_6.15-1' of https://github.com/kvm-x86/linux ↵Paolo Bonzini
into HEAD KVM selftests changes for 6.15, part 1 - Misc cleanups and prep work. - Annotate _no_printf() with "printf" so that pr_debug() statements are checked by the compiler for default builds (and pr_info() when QUIET). - Attempt to whack the last LLC references/misses mole in the Intel PMU counters test by adding a data load and doing CLFLUSH{OPT} on the data instead of the code being executed. The theory is that modern Intel CPUs have learned new code prefetching tricks that bypass the PMU counters. - Fix a flaw in the Intel PMU counters test where it asserts that an event is counting correctly without actually knowing what the event counts on the underlying hardware.
2025-03-19Merge tag 'kvm-x86-misc-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM x86 misc changes for 6.15: - Fix a bug in PIC emulation that caused KVM to emit a spurious KVM_REQ_EVENT. - Add a helper to consolidate handling of mp_state transitions, and use it to clear pv_unhalted whenever a vCPU is made RUNNABLE. - Defer runtime CPUID updates until KVM emulates a CPUID instruction, to coalesce updates when multiple pieces of vCPU state are changing, e.g. as part of a nested transition. - Fix a variety of nested emulation bugs, and add VMX support for synthesizing nested VM-Exit on interception (instead of injecting #UD into L2). - Drop "support" for PV Async #PF with proctected guests without SEND_ALWAYS, as KVM can't get the current CPL. - Misc cleanups
2025-03-19Merge tag 'kvm-x86-mmu-6.15' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM x86/mmu changes for 6.15 Add support for "fast" aging of SPTEs in both the TDP MMU and Shadow MMU, where "fast" means "without holding mmu_lock". Not taking mmu_lock allows multiple aging actions to run in parallel, and more importantly avoids stalling vCPUs, e.g. due to holding mmu_lock for an extended duration while a vCPU is faulting in memory. For the TDP MMU, protect aging via RCU; the page tables are RCU-protected and KVM doesn't need to access any metadata to age SPTEs. For the Shadow MMU, use bit 1 of rmap pointers (bit 0 is used to terminate a list of rmaps) to implement a per-rmap single-bit spinlock. When aging a gfn, acquire the rmap's spinlock with read-only permissions, which allows hardening and optimizing the locking and aging, e.g. locking an rmap for write requires mmu_lock to also be held. The lock is NOT a true R/W spinlock, i.e. multiple concurrent readers aren't supported. To avoid forcing all SPTE updates to use atomic operations (clearing the Accessed bit out of mmu_lock makes it inherently volatile), rework and rename spte_has_volatile_bits() to spte_needs_atomic_update() and deliberately exclude the Accessed bit. KVM (and mm/) already tolerates false positives/negatives for Accessed information, and all testing has shown that reducing the latency of aging is far more beneficial to overall system performance than providing "perfect" young/old information.
2025-03-19Merge tag 'loongarch-kvm-6.15' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.15 1. Remove unnecessary header include path. 2. Remove PGD saving during VM context switch. 3. Add perf events support for guest VM.
2025-03-19Merge tag 'kvm-s390-master-6.14-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD 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.