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2024-03-07Merge branch kvm-arm64/lpi-xarray into kvmarm/nextOliver Upton1-4/+5
* kvm-arm64/lpi-xarray: : xarray-based representation of vgic LPIs : : KVM's linked-list of LPI state has proven to be a bottleneck in LPI : injection paths, due to lock serialization when acquiring / releasing a : reference on an IRQ. : : Start the tedious process of reworking KVM's LPI injection by replacing : the LPI linked-list with an xarray, leveraging this to allow RCU readers : to walk it outside of the spinlock. KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq() KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi() KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner KVM: arm64: vgic: Use atomics to count LPIs KVM: arm64: vgic: Get rid of the LPI linked-list KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list() KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi() KVM: arm64: vgic: Store LPIs in an xarray Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe mannerOliver Upton1-0/+1
Free the vgic_irq structs in an RCU-safe manner to allow reads of the LPI configuration data to happen in parallel with the release of LPIs. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240221054253.3848076-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23KVM: arm64: vgic: Use atomics to count LPIsOliver Upton1-2/+2
Switch to using atomics for LPI accounting, allowing vgic_irq references to be dropped in parallel. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240221054253.3848076-7-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23KVM: arm64: vgic: Get rid of the LPI linked-listOliver Upton1-2/+0
All readers of LPI configuration have been transitioned to use the LPI xarray. Get rid of the linked-list altogether. Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240221054253.3848076-6-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23KVM: arm64: vgic: Store LPIs in an xarrayOliver Upton1-0/+2
Using a linked-list for LPIs is less than ideal as it of course requires iterative searches to find a particular entry. An xarray is a better data structure for this use case, as it provides faster searches and can still handle a potentially sparse range of INTID allocations. Start by storing LPIs in an xarray, punting usage of the xarray to a subsequent change. The observant among you will notice that we added yet another lock to the chain of locking order rules; document the ordering of the xa_lock. Don't worry, we'll get rid of the lpi_list_lock one day... Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240221054253.3848076-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19KVM: arm64: Add feature checking helpersMarc Zyngier1-11/+0
In order to make it easier to check whether a particular feature is exposed to a guest, add a new set of helpers, with kvm_has_feat() being the most useful. Let's start making use of them in the PMU code (courtesy of Oliver). Follow-up changes will introduce additional use patterns. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Co-developed--by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20240214131827.2856277-3-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-31Merge tag 'kvmarm-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEADPaolo Bonzini4-6/+30
KVM/arm64 updates for 6.7 - Generalized infrastructure for 'writable' ID registers, effectively allowing userspace to opt-out of certain vCPU features for its guest - Optimization for vSGI injection, opportunistically compressing MPIDR to vCPU mapping into a table - Improvements to KVM's PMU emulation, allowing userspace to select the number of PMCs available to a VM - Guest support for memory operation instructions (FEAT_MOPS) - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing bugs and getting rid of useless code - Changes to the way the SMCCC filter is constructed, avoiding wasted memory allocations when not in use - Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing the overhead of errata mitigations - Miscellaneous kernel and selftest fixes
2023-10-30Merge branch kvm-arm64/pmu_pmcr_n into kvmarm/nextOliver Upton1-1/+20
* kvm-arm64/pmu_pmcr_n: : User-defined PMC limit, courtesy Raghavendra Rao Ananta : : Certain VMMs may want to reserve some PMCs for host use while running a : KVM guest. This was a bit difficult before, as KVM advertised all : supported counters to the guest. Userspace can now limit the number of : advertised PMCs by writing to PMCR_EL0.N, as KVM's sysreg and PMU : emulation enforce the specified limit for handling guest accesses. KVM: selftests: aarch64: vPMU test for validating user accesses KVM: selftests: aarch64: vPMU register test for unimplemented counters KVM: selftests: aarch64: vPMU register test for implemented counters KVM: selftests: aarch64: Introduce vpmu_counter_access test tools: Import arm_pmuv3.h KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0 KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handler KVM: arm64: PMU: Introduce helpers to set the guest's PMU Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30Merge branch kvm-arm64/sgi-injection into kvmarm/nextOliver Upton1-2/+2
* kvm-arm64/sgi-injection: : vSGI injection improvements + fixes, courtesy Marc Zyngier : : Avoid linearly searching for vSGI targets using a compressed MPIDR to : index a cache. While at it, fix some egregious bugs in KVM's mishandling : of vcpuid (user-controlled value) and vcpu_idx. KVM: arm64: Clarify the ordering requirements for vcpu/RD creation KVM: arm64: vgic-v3: Optimize affinity-based SGI injection KVM: arm64: Fast-track kvm_mpidr_to_vcpu() when mpidr_data is available KVM: arm64: Build MPIDR to vcpu index cache at runtime KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff() KVM: arm64: Use vcpu_idx for invalidation tracking KVM: arm64: vgic: Use vcpu_idx for the debug information KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_id KVM: arm64: vgic-v3: Refactor GICv3 SGI generation KVM: arm64: vgic-its: Treat the collection target address as a vcpu_id KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointer Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30Merge branch kvm-arm64/pmevtyper-filter into kvmarm/nextOliver Upton1-0/+5
* kvm-arm64/pmevtyper-filter: : Fixes to KVM's handling of the PMUv3 exception level filtering bits : : - NSH (count at EL2) and M (count at EL3) should be stateful when the : respective EL is advertised in the ID registers but have no effect on : event counting. : : - NSU and NSK modify the event filtering of EL0 and EL1, respectively. : Though the kernel may not use these bits, other KVM guests might. : Implement these bits exactly as written in the pseudocode if EL3 is : advertised. KVM: arm64: Add PMU event filter bits required if EL3 is implemented KVM: arm64: Make PMEVTYPER<n>_EL0.NSH RES0 if EL2 isn't advertised Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first runRaghavendra Rao Ananta1-1/+2
For unimplemented counters, the registers PM{C,I}NTEN{SET,CLR} and PMOVS{SET,CLR} are expected to have the corresponding bits RAZ. Hence to ensure correct KVM's PMU emulation, mask out the RES0 bits. Defer this work to the point that userspace can no longer change the number of advertised PMCs. Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-7-rananta@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMURaghavendra Rao Ananta1-0/+6
The number of PMU event counters is indicated in PMCR_EL0.N. For a vCPU with PMUv3 configured, the value is set to the same value as the current PE on every vCPU reset. Unless the vCPU is pinned to PEs that has the PMU associated to the guest from the initial vCPU reset, the value might be different from the PMU's PMCR_EL0.N on heterogeneous PMU systems. Fix this by setting the vCPU's PMCR_EL0.N to the PMU's PMCR_EL0.N value. Track the PMCR_EL0.N per guest, as only one PMU can be set for the guest (PMCR_EL0.N must be the same for all vCPUs of the guest), and it is convenient for updating the value. To achieve this, the patch introduces a helper, kvm_arm_pmu_get_max_counters(), that reads the maximum number of counters from the arm_pmu associated to the VM. Make the function global as upcoming patches will be interested to know the value while setting the PMCR.N of the guest from userspace. KVM does not yet support userspace modifying PMCR_EL0.N. The following patch will add support for that. Reviewed-by: Sebastian Ott <sebott@redhat.com> Co-developed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-5-rananta@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0Reiji Watanabe1-0/+6
Add a helper to read a vCPU's PMCR_EL0, and use it whenever KVM reads a vCPU's PMCR_EL0. Currently, the PMCR_EL0 value is tracked per vCPU. The following patches will make (only) PMCR_EL0.N track per guest. Having the new helper will be useful to combine the PMCR_EL0.N field (tracked per guest) and the other fields (tracked per vCPU) to provide the value of PMCR_EL0. No functional change intended. Reviewed-by: Sebastian Ott <sebott@redhat.com> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20231020214053.2144305-4-rananta@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handlerReiji Watanabe1-0/+6
Future changes to KVM's sysreg emulation will rely on having a valid PMU instance to determine the number of implemented counters (PMCR_EL0.N). This is earlier than when userspace is expected to modify the vPMU device attributes, where the default is selected today. Select the default PMU when handling KVM_ARM_VCPU_INIT such that it is available in time for sysreg emulation. Reviewed-by: Sebastian Ott <sebott@redhat.com> Co-developed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> Link: https://lore.kernel.org/r/20231020214053.2144305-3-rananta@google.com [Oliver: rewrite changelog] Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24KVM: arm64: Make PMEVTYPER<n>_EL0.NSH RES0 if EL2 isn't advertisedOliver Upton1-0/+5
The NSH bit, which filters event counting at EL2, is required by the architecture if an implementation has EL2. Even though KVM doesn't support nested virt yet, it makes no effort to hide the existence of EL2 from the ID registers. Userspace can, however, change the value of PFR0 to hide EL2. Align KVM's sysreg emulation with the architecture and make NSH RES0 if EL2 isn't advertised. Keep in mind the bit is ignored when constructing the backing perf event. While at it, build the event type mask using explicit field definitions instead of relying on ARMV8_PMU_EVTYPE_MASK. KVM probably should've been doing this in the first place, as it avoids changes to the aforementioned mask affecting sysreg emulation. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20231019185618.3442949-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-12KVM: arm64: timers: Correctly handle TGE flip with CNTPOFF_EL2Marc Zyngier1-0/+7
Contrary to common belief, HCR_EL2.TGE has a direct and immediate effect on the way the EL0 physical counter is offset. Flipping TGE from 1 to 0 while at EL2 immediately changes the way the counter compared to the CVAL limit. This means that we cannot directly save/restore the guest's view of CVAL, but that we instead must treat it as if CNTPOFF didn't exist. Only in the world switch, once we figure out that we do have CNTPOFF, can we must the offset back and forth depending on the polarity of TGE. Fixes: 2b4825a86940 ("KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer") Reported-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Tested-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-09-30KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointerMarc Zyngier1-2/+2
Passing a vcpu_id to kvm_vgic_inject_irq() is silly for two reasons: - we often confuse vcpu_id and vcpu_idx - we eventually have to convert it back to a vcpu - we can't count Instead, pass a vcpu pointer, which is unambiguous. A NULL vcpu is also allowed for interrupts that are not private to a vcpu (such as SPIs). Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-2-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Get rid of vCPU-scoped feature bitmapOliver Upton2-2/+2
The vCPU-scoped feature bitmap was left in place a couple of releases ago in case the change to VM-scoped vCPU features broke anyone. Nobody has complained and the interop between VM and vCPU bitmaps is pretty gross. Throw it out. Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21KVM: arm64: Remove unused return value from kvm_reset_vcpu()Oliver Upton1-1/+1
Get rid of the return value for kvm_reset_vcpu() as there are no longer any cases where it returns a nonzero value. Link: https://lore.kernel.org/r/20230920195036.1169791-8-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-08-23KVM: arm64: pmu: Guard PMU emulation definitions with CONFIG_KVMMarc Zyngier1-1/+1
Most of the internal definitions for PMU emulation are guarded with CONFIG_HW_PERF_EVENTS. However, this isn't enough, and leads to these definitions leaking if CONFIG_KVM isn't enabled. This leads to some compilation breakage in this exact configuration. Fix it by falling back to the dummy stubs if either perf or KVM isn't selected. Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com> Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-22KVM: arm64: pmu: Resync EL0 state on counter rotationMarc Zyngier1-0/+2
Huang Shijie reports that, when profiling a guest from the host with a number of events that exceeds the number of available counters, the reported counts are wildly inaccurate. Without the counter oversubscription, the reported counts are correct. Their investigation indicates that upon counter rotation (which takes place on the back of a timer interrupt), we fail to re-apply the guest EL0 enabling, leading to the counting of host events instead of guest events. In order to solve this, add yet another hook between the host PMU driver and KVM, re-applying the guest EL0 configuration if the right conditions apply (the host is VHE, we are in interrupt context, and we interrupted a running vcpu). This triggers a new vcpu request which will apply the correct configuration on guest reentry. With this, we have the correct counts, even when the counters are oversubscribed. Reported-by: Huang Shijie <shijie@os.amperecomputing.com> Suggested-by: Oliver Upton <oliver.upton@linux.dev> Tested_by: Huang Shijie <shijie@os.amperecomputing.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20230809013953.7692-1-shijie@os.amperecomputing.com Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20230820090108.177817-1-maz@kernel.org
2023-07-13KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemptionMarc Zyngier1-1/+1
Xiang reports that VMs occasionally fail to boot on GICv4.1 systems when running a preemptible kernel, as it is possible that a vCPU is blocked without requesting a doorbell interrupt. The issue is that any preemption that occurs between vgic_v4_put() and schedule() on the block path will mark the vPE as nonresident and *not* request a doorbell irq. This occurs because when the vcpu thread is resumed on its way to block, vcpu_load() will make the vPE resident again. Once the vcpu actually blocks, we don't request a doorbell anymore, and the vcpu won't be woken up on interrupt delivery. Fix it by tracking that we're entering WFI, and key the doorbell request on that flag. This allows us not to make the vPE resident when going through a preempt/schedule cycle, meaning we don't lose any state. Cc: stable@vger.kernel.org Fixes: 8e01d9a396e6 ("KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put") Reported-by: Xiang Chen <chenxiang66@hisilicon.com> Suggested-by: Zenghui Yu <yuzenghui@huawei.com> Tested-by: Xiang Chen <chenxiang66@hisilicon.com> Co-developed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Zenghui Yu <yuzenghui@huawei.com> Link: https://lore.kernel.org/r/20230713070657.3873244-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-07-01Merge tag 'kvm-x86-generic-6.5' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-6/+0
Common KVM changes for 6.5: - Fix unprotected vcpu->pid dereference via debugfs - Fix KVM_BUG() and KVM_BUG_ON() macros with 64-bit conditionals - Refactor failure path in kvm_io_bus_unregister_dev() to simplify the code - Misc cleanups
2023-06-15KVM: arm64: Rip out the vestiges of the 'old' ID register schemeOliver Upton1-2/+6
There's no longer a need for the baggage of the old scheme for handling configurable ID register fields. Rip it all out in favor of the generalized infrastructure. Link: https://lore.kernel.org/r/20230609190054.1542113-12-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-13KVM: destruct kvm_io_device while unregistering it from kvm_io_busWei Wang1-6/+0
Current usage of kvm_io_device requires users to destruct it with an extra call of kvm_iodevice_destructor after the device gets unregistered from kvm_io_bus. This is not necessary and can cause errors if a user forgot to make the extra call. Simplify the usage by combining kvm_iodevice_destructor into kvm_io_bus_unregister_dev. This reduces LOCs a bit for users and can avoid the leakage of destructing the device explicitly. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20230207123713.3905-2-wei.w.wang@intel.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-12KVM: arm64: Rewrite IMPDEF PMU version as NIOliver Upton1-1/+1
KVM allows userspace to write an IMPDEF PMU version to the corresponding 32bit and 64bit ID register fields for the sake of backwards compatibility with kernels that lacked commit 3d0dba5764b9 ("KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation"). Plumbing that IMPDEF PMU version through to the gues is getting in the way of progress, and really doesn't any sense in the first place. Bite the bullet and reinterpret the IMPDEF PMU version as NI (0) for userspace writes. Additionally, spill the dirty details into a comment. Link: https://lore.kernel.org/r/20230609190054.1542113-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds3-7/+34
Pull kvm updates from Paolo Bonzini: "s390: - More phys_to_virt conversions - Improvement of AP management for VSIE (nested virtualization) ARM64: - Numerous fixes for the pathological lock inversion issue that plagued KVM/arm64 since... forever. - New framework allowing SMCCC-compliant hypercalls to be forwarded to userspace, hopefully paving the way for some more features being moved to VMMs rather than be implemented in the kernel. - Large rework of the timer code to allow a VM-wide offset to be applied to both virtual and physical counters as well as a per-timer, per-vcpu offset that complements the global one. This last part allows the NV timer code to be implemented on top. - A small set of fixes to make sure that we don't change anything affecting the EL1&0 translation regime just after having having taken an exception to EL2 until we have executed a DSB. This ensures that speculative walks started in EL1&0 have completed. - The usual selftest fixes and improvements. x86: - Optimize CR0.WP toggling by avoiding an MMU reload when TDP is enabled, and by giving the guest control of CR0.WP when EPT is enabled on VMX (VMX-only because SVM doesn't support per-bit controls) - Add CR0/CR4 helpers to query single bits, and clean up related code where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long" return as a bool - Move AMD_PSFD to cpufeatures.h and purge KVM's definition - Avoid unnecessary writes+flushes when the guest is only adding new PTEs - Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s optimizations when emulating invalidations - Clean up the range-based flushing APIs - Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a single A/D bit using a LOCK AND instead of XCHG, and skip all of the "handle changed SPTE" overhead associated with writing the entire entry - Track the number of "tail" entries in a pte_list_desc to avoid having to walk (potentially) all descriptors during insertion and deletion, which gets quite expensive if the guest is spamming fork() - Disallow virtualizing legacy LBRs if architectural LBRs are available, the two are mutually exclusive in hardware - Disallow writes to immutable feature MSRs (notably PERF_CAPABILITIES) after KVM_RUN, similar to CPUID features - Overhaul the vmx_pmu_caps selftest to better validate PERF_CAPABILITIES - Apply PMU filters to emulated events and add test coverage to the pmu_event_filter selftest - AMD SVM: - Add support for virtual NMIs - Fixes for edge cases related to virtual interrupts - Intel AMX: - Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if XTILE_DATA is not being reported due to userspace not opting in via prctl() - Fix a bug in emulation of ENCLS in compatibility mode - Allow emulation of NOP and PAUSE for L2 - AMX selftests improvements - Misc cleanups MIPS: - Constify MIPS's internal callbacks (a leftover from the hardware enabling rework that landed in 6.3) Generic: - Drop unnecessary casts from "void *" throughout kvm_main.c - Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the struct size by 8 bytes on 64-bit kernels by utilizing a padding hole Documentation: - Fix goof introduced by the conversion to rST" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (211 commits) KVM: s390: pci: fix virtual-physical confusion on module unload/load KVM: s390: vsie: clarifications on setting the APCB KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init() KVM: selftests: Test the PMU event "Instructions retired" KVM: selftests: Copy full counter values from guest in PMU event filter test KVM: selftests: Use error codes to signal errors in PMU event filter test KVM: selftests: Print detailed info in PMU event filter asserts KVM: selftests: Add helpers for PMC asserts in PMU event filter test KVM: selftests: Add a common helper for the PMU event filter guest code KVM: selftests: Fix spelling mistake "perrmited" -> "permitted" KVM: arm64: vhe: Drop extra isb() on guest exit KVM: arm64: vhe: Synchronise with page table walker on MMU update KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc() KVM: arm64: nvhe: Synchronise with page table walker on TLBI KVM: arm64: Handle 32bit CNTPCTSS traps KVM: arm64: nvhe: Synchronise with page table walker on vcpu run KVM: arm64: vgic: Don't acquire its_lock before config_lock KVM: selftests: Add test to verify KVM's supported XCR0 ...
2023-04-21Merge branch kvm-arm64/smccc-filtering into kvmarm-master/nextMarc Zyngier1-1/+5
* kvm-arm64/smccc-filtering: : . : SMCCC call filtering and forwarding to userspace, courtesy of : Oliver Upton. From the cover letter: : : "The Arm SMCCC is rather prescriptive in regards to the allocation of : SMCCC function ID ranges. Many of the hypercall ranges have an : associated specification from Arm (FF-A, PSCI, SDEI, etc.) with some : room for vendor-specific implementations. : : The ever-expanding SMCCC surface leaves a lot of work within KVM for : providing new features. Furthermore, KVM implements its own : vendor-specific ABI, with little room for other implementations (like : Hyper-V, for example). Rather than cramming it all into the kernel we : should provide a way for userspace to handle hypercalls." : . KVM: selftests: Fix spelling mistake "KVM_HYPERCAL_EXIT_SMC" -> "KVM_HYPERCALL_EXIT_SMC" KVM: arm64: Test that SMC64 arch calls are reserved KVM: arm64: Prevent userspace from handling SMC64 arch range KVM: arm64: Expose SMC/HVC width to userspace KVM: selftests: Add test for SMCCC filter KVM: selftests: Add a helper for SMCCC calls with SMC instruction KVM: arm64: Let errors from SMCCC emulation to reach userspace KVM: arm64: Return NOT_SUPPORTED to guest for unknown PSCI version KVM: arm64: Introduce support for userspace SMCCC filtering KVM: arm64: Add support for KVM_EXIT_HYPERCALL KVM: arm64: Use a maple tree to represent the SMCCC filter KVM: arm64: Refactor hvc filtering to support different actions KVM: arm64: Start handling SMCs from EL1 KVM: arm64: Rename SMC/HVC call handler to reflect reality KVM: arm64: Add vm fd device attribute accessors KVM: arm64: Add a helper to check if a VM has ran once KVM: x86: Redefine 'longmode' as a flag for KVM_EXIT_HYPERCALL Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-21Merge branch kvm-arm64/timer-vm-offsets into kvmarm-master/nextMarc Zyngier2-6/+29
* kvm-arm64/timer-vm-offsets: (21 commits) : . : This series aims at satisfying multiple goals: : : - allow a VMM to atomically restore a timer offset for a whole VM : instead of updating the offset each time a vcpu get its counter : written : : - allow a VMM to save/restore the physical timer context, something : that we cannot do at the moment due to the lack of offsetting : : - provide a framework that is suitable for NV support, where we get : both global and per timer, per vcpu offsetting, and manage : interrupts in a less braindead way. : : Conflict resolution involves using the new per-vcpu config lock instead : of the home-grown timer lock. : . KVM: arm64: Handle 32bit CNTPCTSS traps KVM: arm64: selftests: Augment existing timer test to handle variable offset KVM: arm64: selftests: Deal with spurious timer interrupts KVM: arm64: selftests: Add physical timer registers to the sysreg list KVM: arm64: nv: timers: Support hyp timer emulation KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and co KVM: arm64: timers: Abstract the number of valid timers per vcpu KVM: arm64: timers: Fast-track CNTPCT_EL0 trap handling KVM: arm64: Elide kern_hyp_va() in VHE-specific parts of the hypervisor KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data KVM: arm64: timers: Abstract per-timer IRQ access KVM: arm64: timers: Rationalise per-vcpu timer init KVM: arm64: timers: Allow save/restoring of the physical timer KVM: arm64: timers: Allow userspace to set the global counter offset KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2 KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer arm64: Add HAS_ECV_CNTPOFF capability arm64: Add CNTPOFF_EL2 register definition ... Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-05KVM: arm64: Introduce support for userspace SMCCC filteringOliver Upton1-0/+3
As the SMCCC (and related specifications) march towards an 'everything and the kitchen sink' interface for interacting with a system it becomes less likely that KVM will support every related feature. We could do better by letting userspace have a crack at it instead. Allow userspace to define an 'SMCCC filter' that applies to both HVCs and SMCs initiated by the guest. Supporting both conduits with this interface is important for a couple of reasons. Guest SMC usage is table stakes for a nested guest, as HVCs are always taken to the virtual EL2. Additionally, guests may want to interact with a service on the secure side which can now be proxied by userspace. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-10-oliver.upton@linux.dev
2023-04-05KVM: arm64: Use a maple tree to represent the SMCCC filterOliver Upton1-0/+1
Maple tree is an efficient B-tree implementation that is intended for storing non-overlapping intervals. Such a data structure is a good fit for the SMCCC filter as it is desirable to sparsely allocate the 32 bit function ID space. To that end, add a maple tree to kvm_arch and correctly init/teardown along with the VM. Wire in a test against the hypercall filter for HVCs which does nothing until the controls are exposed to userspace. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-8-oliver.upton@linux.dev
2023-04-05KVM: arm64: Rename SMC/HVC call handler to reflect realityOliver Upton1-1/+1
KVM handles SMCCC calls from virtual EL2 that use the SMC instruction since commit bd36b1a9eb5a ("KVM: arm64: nv: Handle SMCs taken from virtual EL2"). Thus, the function name of the handler no longer reflects reality. Normalize the name on SMCCC, since that's the only hypercall interface KVM supports in the first place. No fuctional change intended. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-5-oliver.upton@linux.dev
2023-03-30KVM: arm64: nv: timers: Support hyp timer emulationMarc Zyngier2-2/+8
Emulating EL2 also means emulating the EL2 timers. To do so, we expand our timer framework to deal with at most 4 timers. At any given time, two timers are using the HW timers, and the two others are purely emulated. The role of deciding which is which at any given time is left to a mapping function which is called every time we need to make such a decision. Reviewed-by: Colton Lewis <coltonlewis@google.com> Co-developed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-18-maz@kernel.org
2023-03-30KVM: arm64: nv: timers: Add a per-timer, per-vcpu offsetMarc Zyngier1-0/+5
Being able to set a global offset isn't enough. With NV, we also need to a per-vcpu, per-timer offset (for example, CNTVCT_EL0 being offset by CNTVOFF_EL2). Use a similar method as the VM-wide offset to have a timer point to the shadow register that contains the offset value. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-17-maz@kernel.org
2023-03-30KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_dataMarc Zyngier1-4/+14
Having the timer IRQs duplicated into each vcpu isn't great, and becomes absolutely awful with NV. So let's move these into the per-VM arch_timer_vm_data structure. This simplifies a lot of code, but requires us to introduce a mutex so that we can reason about userspace trying to change an interrupt number while another vcpu is running, something that wasn't really well handled so far. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-12-maz@kernel.org
2023-03-30KVM: arm64: timers: Abstract per-timer IRQ accessMarc Zyngier1-0/+2
As we are about to move the location of the per-timer IRQ into the VM structure, abstract the location of the IRQ behind an accessor. This will make the repainting sligntly less painful. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-11-maz@kernel.org
2023-03-30KVM: arm64: timers: Rationalise per-vcpu timer initMarc Zyngier1-1/+0
The way we initialise our timer contexts may be satisfactory for two timers, but will be getting pretty annoying with four. Cleanup the whole thing by removing the code duplication and getting rid of unused IRQ configuration elements. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-10-maz@kernel.org
2023-03-30KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timerMarc Zyngier1-0/+2
With ECV and CNTPOFF_EL2, it is very easy to offer an offset for the physical timer. So let's do just that. Nothing can set the offset yet, so this should have no effect whatsoever (famous last words...). Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-5-maz@kernel.org
2023-03-30KVM: arm64: timers: Use a per-vcpu, per-timer accumulator for fractional nsMarc Zyngier1-0/+1
Instead of accumulating the fractional ns value generated every time we compute a ns delta in a global variable, use a per-vcpu, per-timer variable. This keeps the fractional ns local to the timer instead of contributing to any odd, unrelated timer. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-2-maz@kernel.org
2023-03-27arm64: perf: Move PMUv3 driver to drivers/perfMarc Zyngier1-1/+1
Having the ARM PMUv3 driver sitting in arch/arm64/kernel is getting in the way of being able to use perf on ARMv8 cores running a 32bit kernel, such as 32bit KVM guests. This patch moves it into drivers/perf/arm_pmuv3.c, with an include file in include/linux/perf/arm_pmuv3.h. The only thing left in arch/arm64 is some mundane perf stuff. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Zaid Al-Bassam <zalbassam@google.com> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/20230317195027.3746949-2-zalbassam@google.com Signed-off-by: Will Deacon <will@kernel.org>
2023-03-11KVM: arm64: timers: Convert per-vcpu virtual offset to a global valueMarc Zyngier1-0/+15
Having a per-vcpu virtual offset is a pain. It needs to be synchronized on each update, and expands badly to a setup where different timers can have different offsets, or have composite offsets (as with NV). So let's start by replacing the use of the CNTVOFF_EL2 shadow register (which we want to reclaim for NV anyway), and make the virtual timer carry a pointer to a VM-wide offset. This simplifies the code significantly. It also addresses two terrible bugs: - The use of CNTVOFF_EL2 leads to some nice offset corruption when the sysreg gets reset, as reported by Joey. - The kvm mutex is taken from a vcpu ioctl, which goes against the locking rules... Reported-by: Joey Gouly <joey.gouly@arm.com> Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230224173915.GA17407@e124191.cambridge.arm.com Tested-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/20230224191640.3396734-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-15Merge tag 'kvm-riscv-6.3-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini1-1/+1
KVM/riscv changes for 6.3 - Fix wrong usage of PGDIR_SIZE to check page sizes - Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect() - Redirect illegal instruction traps to guest - SBI PMU support for guest
2023-01-29KVM: arm64: Add helper vgic_write_guest_lock()Gavin Shan1-1/+1
Currently, the unknown no-running-vcpu sites are reported when a dirty page is tracked by mark_page_dirty_in_slot(). Until now, the only known no-running-vcpu site is saving vgic/its tables through KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_SAVE_TABLES} command on KVM device "kvm-arm-vgic-its". Unfortunately, there are more unknown sites to be handled and no-running-vcpu context will be allowed in these sites: (1) KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} command on KVM device "kvm-arm-vgic-its" to restore vgic/its tables. The vgic3 LPI pending status could be restored. (2) Save vgic3 pending table through KVM_DEV_ARM_{VGIC_GRP_CTRL, VGIC_SAVE_PENDING_TABLES} command on KVM device "kvm-arm-vgic-v3". In order to handle those unknown cases, we need a unified helper vgic_write_guest_lock(). struct vgic_dist::save_its_tables_in_progress is also renamed to struct vgic_dist::save_tables_in_progress. No functional change intended. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230126235451.469087-3-gshan@redhat.com
2022-12-29KVM: x86: Unify pr_fmt to use module name for all KVM modulesSean Christopherson1-1/+1
Define pr_fmt using KBUILD_MODNAME for all KVM x86 code so that printks use consistent formatting across common x86, Intel, and AMD code. In addition to providing consistent print formatting, using KBUILD_MODNAME, e.g. kvm_amd and kvm_intel, allows referencing SVM and VMX (and SEV and SGX and ...) as technologies without generating weird messages, and without causing naming conflicts with other kernel code, e.g. "SEV: ", "tdx: ", "sgx: " etc.. are all used by the kernel for non-KVM subsystems. Opportunistically move away from printk() for prints that need to be modified anyways, e.g. to drop a manual "kvm: " prefix. Opportunistically convert a few SGX WARNs that are similarly modified to WARN_ONCE; in the very unlikely event that the WARNs fire, odds are good that they would fire repeatedly and spam the kernel log without providing unique information in each print. Note, defining pr_fmt yields undesirable results for code that uses KVM's printk wrappers, e.g. vcpu_unimpl(). But, that's a pre-existing problem as SVM/kvm_amd already defines a pr_fmt, and thankfully use of KVM's wrappers is relatively limited in KVM x86 code. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Paul Durrant <paul@xen.org> Message-Id: <20221130230934.1014142-35-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29KVM: arm64: Simplify the CPUHP logicMarc Zyngier2-0/+8
For a number of historical reasons, the KVM/arm64 hotplug setup is pretty complicated, and we have two extra CPUHP notifiers for vGIC and timers. It looks pretty pointless, and gets in the way of further changes. So let's just expose some helpers that can be called from the core CPUHP callback, and get rid of everything else. This gives us the opportunity to drop a useless notifier entry, as well as tidy-up the timer enable/disable, which was a bit odd. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221130230934.1014142-17-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-05Merge branch kvm-arm64/pmu-unchained into kvmarm-master/nextMarc Zyngier1-2/+13
* kvm-arm64/pmu-unchained: : . : PMUv3 fixes and improvements: : : - Make the CHAIN event handling strictly follow the architecture : : - Add support for PMUv3p5 (64bit counters all the way) : : - Various fixes and cleanups : . KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow KVM: arm64: PMU: Sanitise PMCR_EL0.LP on first vcpu run KVM: arm64: PMU: Simplify PMCR_EL0 reset handling KVM: arm64: PMU: Replace version number '0' with ID_AA64DFR0_EL1_PMUVer_NI KVM: arm64: PMU: Make kvm_pmc the main data structure KVM: arm64: PMU: Simplify vcpu computation on perf overflow notification KVM: arm64: PMU: Allow PMUv3p5 to be exposed to the guest KVM: arm64: PMU: Implement PMUv3p5 long counter support KVM: arm64: PMU: Allow ID_DFR0_EL1.PerfMon to be set from userspace KVM: arm64: PMU: Allow ID_AA64DFR0_EL1.PMUver to be set from userspace KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation KVM: arm64: PMU: Do not let AArch32 change the counters' top 32 bits KVM: arm64: PMU: Simplify setting a counter to a specific value KVM: arm64: PMU: Add counter_index_to_*reg() helpers KVM: arm64: PMU: Only narrow counters that are not 64bit wide KVM: arm64: PMU: Narrow the overflow checking when required KVM: arm64: PMU: Distinguish between 64bit counter and 64bit overflow KVM: arm64: PMU: Always advertise the CHAIN event KVM: arm64: PMU: Align chained counter implementation with architecture pseudocode arm64: Add ID_DFR0_EL1.PerfMon values for PMUv3p7 and IMP_DEF Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-11-19KVM: arm64: PMU: Implement PMUv3p5 long counter supportMarc Zyngier1-0/+7
PMUv3p5 (which is mandatory with ARMv8.5) comes with some extra features: - All counters are 64bit - The overflow point is controlled by the PMCR_EL0.LP bit Add the required checks in the helpers that control counter width and overflow, as well as the sysreg handling for the LP bit. A new kvm_pmu_is_3p5() helper makes it easy to spot the PMUv3p5 specific handling. Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221113163832.3154370-14-maz@kernel.org
2022-11-19KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creationMarc Zyngier1-0/+6
As further patches will enable the selection of a PMU revision from userspace, sample the supported PMU revision at VM creation time, rather than building each time the ID_AA64DFR0_EL1 register is accessed. This shouldn't result in any change in behaviour. Reviewed-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221113163832.3154370-11-maz@kernel.org
2022-11-17KVM: arm64: PMU: Align chained counter implementation with architecture pseudocodeMarc Zyngier1-2/+0
Ricardo recently pointed out that the PMU chained counter emulation in KVM wasn't quite behaving like the one on actual hardware, in the sense that a chained counter would expose an overflow on both halves of a chained counter, while KVM would only expose the overflow on the top half. The difference is subtle, but significant. What does the architecture say (DDI0087 H.a): - Up to PMUv3p4, all counters but the cycle counter are 32bit - A 32bit counter that overflows generates a CHAIN event on the adjacent counter after exposing its own overflow status - The CHAIN event is accounted if the counter is correctly configured (CHAIN event selected and counter enabled) This all means that our current implementation (which uses 64bit perf events) prevents us from emulating this overflow on the lower half. How to fix this? By implementing the above, to the letter. This largely results in code deletion, removing the notions of "counter pair", "chained counters", and "canonical counter". The code is further restructured to make the CHAIN handling similar to SWINC, as the two are now extremely similar in behaviour. Reported-by: Ricardo Koller <ricarkol@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Reiji Watanabe <reijiw@google.com> Link: https://lore.kernel.org/r/20221113163832.3154370-3-maz@kernel.org
2022-11-10KVM: arm64: Enable ring-based dirty memory trackingGavin Shan1-0/+1
Enable ring-based dirty memory tracking on ARM64: - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL. - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP. - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page offset. - Add ARM64 specific kvm_arch_allow_write_without_running_vcpu() to keep the site of saving vgic/its tables out of the no-running-vcpu radar. Signed-off-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110104914.31280-5-gshan@redhat.com