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2025-04-11KVM: arm64: Allow userspace to limit the number of PMU counters for EL2 VMsMarc Zyngier
As long as we had purely EL1 VMs, we could easily update the number of guest-visible counters by letting userspace write to PMCR_EL0.N. With VMs started at EL2, PMCR_EL1.N only reflects MDCR_EL2.HPMN, and we don't have a good way to limit it. For this purpose, introduce a new PMUv3 attribute that allows limiting the maximum number of counters. This requires the explicit selection of a PMU. Suggested-by: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
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>
2025-03-03KVM: arm64: nv: Allow userland to set VGIC maintenance IRQAndre Przywara
The VGIC maintenance IRQ signals various conditions about the LRs, when the GIC's virtualization extension is used. So far we didn't need it, but nested virtualization needs to know about this interrupt, so add a userland interface to setup the IRQ number. The architecture mandates that it must be a PPI, on top of that this code only exports a per-device option, so the PPI is the same on all VCPUs. Signed-off-by: Andre Przywara <andre.przywara@arm.com> [added some bits of documentation] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250225172930.1850838-16-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26KVM: arm64: Document ordering requirements for irqbypassOliver Upton
One of the not-so-obvious requirements for restoring a VM is ensuring that the vITS has been restored _before_ creating any irqbypass mappings. This is because KVM needs to get the guest translation for MSIs to correctly assemble the vLPI mapping getting installed in the physical ITS. Document the restore ordering requirements necessary for GICv4 vLPI injection to work. Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20250226183124.82094-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-01-28Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull KVM/arm64 updates from Will Deacon: "New features: - Support for non-protected guest in protected mode, achieving near feature parity with the non-protected mode - Support for the EL2 timers as part of the ongoing NV support - Allow control of hardware tracing for nVHE/hVHE Improvements, fixes and cleanups: - Massive cleanup of the debug infrastructure, making it a bit less awkward and definitely easier to maintain. This should pave the way for further optimisations - Complete rewrite of pKVM's fixed-feature infrastructure, aligning it with the rest of KVM and making the code easier to follow - Large simplification of pKVM's memory protection infrastructure - Better handling of RES0/RES1 fields for memory-backed system registers - Add a workaround for Qualcomm's Snapdragon X CPUs, which suffer from a pretty nasty timer bug - Small collection of cleanups and low-impact fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (87 commits) arm64/sysreg: Get rid of TRFCR_ELx SysregFields KVM: arm64: nv: Fix doc header layout for timers KVM: arm64: nv: Apply RESx settings to sysreg reset values KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessors KVM: arm64: Fix selftests after sysreg field name update coresight: Pass guest TRFCR value to KVM KVM: arm64: Support trace filtering for guests KVM: arm64: coresight: Give TRBE enabled state to KVM coresight: trbe: Remove redundant disable call arm64/sysreg/tools: Move TRFCR definitions to sysreg tools: arm64: Update sysreg.h header files KVM: arm64: Drop pkvm_mem_transition for host/hyp donations KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing KVM: arm64: Drop pkvm_mem_transition for FF-A KVM: arm64: Explicitly handle BRBE traps as UNDEFINED KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe() arm64: kvm: Introduce nvhe stack size constants KVM: arm64: Fix nVHE stacktrace VA bits mask KVM: arm64: Fix FEAT_MTE in pKVM Documentation: Update the behaviour of "kvm-arm.mode" ...
2025-01-16KVM: arm64: nv: Fix doc header layout for timersMarc Zyngier
Stephen reports that 'make htmldocs' spits out a warning ("Documentation/virt/kvm/devices/vcpu.rst:147: WARNING: Definition list ends without a blank line; unexpected unindent."). Fix it by keeping all the timer attributes on a single line. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-07KVM: s390: Reject setting flic pfault attributes on ucontrol VMsChristoph Schlameuss
Prevent null pointer dereference when processing the KVM_DEV_FLIC_APF_ENABLE and KVM_DEV_FLIC_APF_DISABLE_WAIT ioctls in the interrupt controller. Fixes: 3c038e6be0e2 ("KVM: async_pf: Async page fault support on s390") Reported-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Hariharan Mari <hari55@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20241216092140.329196-2-schlameuss@linux.ibm.com Message-ID: <20241216092140.329196-2-schlameuss@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2025-01-02KVM: arm64: nv: Document EL2 timer APIMarc Zyngier
Acked-by: Oliver Upton <oliver.upton@linux.dev> Link: https://lore.kernel.org/r/20241217142321.763801-13-maz@kernel.org Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-06-28KVM: Documentation: Correct the VGIC V2 CPU interface addr space sizeChangyuan Lyu
In arch/arm64/include/uapi/asm/kvm.h, we have #define KVM_VGIC_V2_CPU_SIZE 0x2000 So the CPU interface address space should cover 8 KByte not 4 KByte. Signed-off-by: Changyuan Lyu <changyuanl@google.com> Link: https://lore.kernel.org/r/20240623164542.2999626-3-changyuanl@google.com Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30KVM: arm64: Clarify the ordering requirements for vcpu/RD creationMarc Zyngier
It goes without saying, but it is probably better to spell it out: If userspace tries to restore and VM, but creates vcpus and/or RDs in a different order, the vcpu/RD mapping will be different. Yes, our API is an ugly piece of crap and I can't believe that we missed this. If we want to relax the above, we'll need to define a new userspace API that allows the mapping to be specified, rather than relying on the kernel to perform the mapping on its own. Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230927090911.3355209-12-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-08-30Merge tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - VFIO direct character device (cdev) interface support. This extracts the vfio device fd from the container and group model, and is intended to be the native uAPI for use with IOMMUFD (Yi Liu) - Enhancements to the PCI hot reset interface in support of cdev usage (Yi Liu) - Fix a potential race between registering and unregistering vfio files in the kvm-vfio interface and extend use of a lock to avoid extra drop and acquires (Dmitry Torokhov) - A new vfio-pci variant driver for the AMD/Pensando Distributed Services Card (PDS) Ethernet device, supporting live migration (Brett Creeley) - Cleanups to remove redundant owner setup in cdx and fsl bus drivers, and simplify driver init/exit in fsl code (Li Zetao) - Fix uninitialized hole in data structure and pad capability structures for alignment (Stefan Hajnoczi) * tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio: (53 commits) vfio/pds: Send type for SUSPEND_STATUS command vfio/pds: fix return value in pds_vfio_get_lm_file() pds_core: Fix function header descriptions vfio: align capability structures vfio/type1: fix cap_migration information leak vfio/fsl-mc: Use module_fsl_mc_driver macro to simplify the code vfio/cdx: Remove redundant initialization owner in vfio_cdx_driver vfio/pds: Add Kconfig and documentation vfio/pds: Add support for firmware recovery vfio/pds: Add support for dirty page tracking vfio/pds: Add VFIO live migration support vfio/pds: register with the pds_core PF pds_core: Require callers of register/unregister to pass PF drvdata vfio/pds: Initial support for pds VFIO driver vfio: Commonize combine_ranges for use in other VFIO drivers kvm/vfio: avoid bouncing the mutex when adding and deleting groups kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add() docs: vfio: Add vfio device cdev description vfio: Compile vfio_group infrastructure optionally vfio: Move the IOMMU_CAP_CACHE_COHERENCY check in __vfio_register_dev() ...
2023-08-18Documentation: Fix typosBjorn Helgaas
Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-07-25kvm/vfio: Accept vfio device file from userspaceYi Liu
This defines KVM_DEV_VFIO_FILE* and make alias with KVM_DEV_VFIO_GROUP*. Old userspace uses KVM_DEV_VFIO_GROUP* works as well. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Tested-by: Terrence Xu <terrence.xu@intel.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> Tested-by: Yanting Jiang <yanting.jiang@intel.com> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20230718135551.6592-6-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-05-02Merge tag 'vfio-v6.4-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Expose and allow R/W access to the PCIe DVSEC capability through vfio-pci, as we already do with the legacy vendor capability (K V P Satyanarayana) - Fix kernel-doc issues with structure definitions (Simon Horman) - Clarify ordering of operations relative to the kvm-vfio device for driver dependencies against the kvm pointer (Yi Liu) * tag 'vfio-v6.4-rc1' of https://github.com/awilliam/linux-vfio: docs: kvm: vfio: Suggest KVM_DEV_VFIO_GROUP_ADD vs VFIO_GROUP_GET_DEVICE_FD ordering vfio: correct kdoc for ops structures vfio/pci: Add DVSEC PCI Extended Config Capability to user visible list.
2023-04-21docs: kvm: vfio: Suggest KVM_DEV_VFIO_GROUP_ADD vs VFIO_GROUP_GET_DEVICE_FD ↵Yi Liu
ordering as some vfio_device's open_device op requires kvm pointer and kvm pointer set is part of GROUP_ADD. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20230421053611.55839-1-yi.l.liu@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-04-05KVM: arm64: Introduce support for userspace SMCCC filteringOliver Upton
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
2023-02-07KVM: s390: disable migration mode when dirty tracking is disabledNico Boehr
Migration mode is a VM attribute which enables tracking of changes in storage attributes (PGSTE). It assumes dirty tracking is enabled on all memslots to keep a dirty bitmap of pages with changed storage attributes. When enabling migration mode, we currently check that dirty tracking is enabled for all memslots. However, userspace can disable dirty tracking without disabling migration mode. Since migration mode is pointless with dirty tracking disabled, disable migration mode whenever userspace disables dirty tracking on any slot. Also update the documentation to clarify that dirty tracking must be enabled when enabling migration mode, which is already enforced by the code in kvm_s390_vm_start_migration(). Also highlight in the documentation for KVM_S390_GET_CMMA_BITS that it can now fail with -EINVAL when dirty tracking is disabled while migration mode is on. Move all the error codes to a table so this stays readable. To disable migration mode, slots_lock should be held, which is taken in kvm_set_memory_region() and thus held in kvm_arch_prepare_memory_region(). Restructure the prepare code a bit so all the sanity checking is done before disabling migration mode. This ensures migration mode isn't disabled when some sanity check fails. Cc: stable@vger.kernel.org Fixes: 190df4a212a7 ("KVM: s390: CMMA tracking, ESSA emulation, migration mode") Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20230127140532.230651-2-nrb@linux.ibm.com Message-Id: <20230127140532.230651-2-nrb@linux.ibm.com> [frankja@linux.ibm.com: fixed commit message typo, moved api.rst error table upwards] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-12-09Merge tag 'kvmarm-6.2' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.2 - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on. - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Add/Enable/Fix a bunch of selftests covering memslots, breakpoints, stage-2 faults and access tracking. You name it, we got it, we probably broke it. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. As a side effect, this tag also drags: - The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring series - A shared branch with the arm64 tree that repaints all the system registers to match the ARM ARM's naming, and resulting in interesting conflicts
2022-12-05Merge branch kvm-arm64/misc-6.2 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/misc-6.2: : . : Misc fixes for 6.2: : : - Fix formatting for the pvtime documentation : : - Fix a comment in the VHE-specific Makefile : . KVM: arm64: Fix typo in comment KVM: arm64: Fix pvtime documentation Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-11-11KVM: arm64: Fix pvtime documentationUsama Arif
This includes table format and using reST labels for cross-referencing to vcpu.rst. Suggested-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Usama Arif <usama.arif@bytedance.com> Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221103131210.3603385-1-usama.arif@bytedance.com
2022-11-10KVM: Support dirty ring in conjunction with bitmapGavin Shan
ARM64 needs to dirty memory outside of a VCPU context when VGIC/ITS is enabled. It's conflicting with that ring-based dirty page tracking always requires a running VCPU context. Introduce a new flavor of dirty ring that requires the use of both VCPU dirty rings and a dirty bitmap. The expectation is that for non-VCPU sources of dirty memory (such as the VGIC/ITS on arm64), KVM writes to the dirty bitmap. Userspace should scan the dirty bitmap before migrating the VM to the target. Use an additional capability to advertise this behavior. The newly added capability (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) can't be enabled before KVM_CAP_DIRTY_LOG_RING_ACQ_REL on ARM64. In this way, the newly added capability is treated as an extension of KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Suggested-by: Marc Zyngier <maz@kernel.org> Suggested-by: Peter Xu <peterx@redhat.com> Co-developed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Gavin Shan <gshan@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110104914.31280-4-gshan@redhat.com
2022-11-07KVM: s390: pv: don't allow userspace to set the clock under PVNico Boehr
When running under PV, the guest's TOD clock is under control of the ultravisor and the hypervisor isn't allowed to change it. Hence, don't allow userspace to change the guest's TOD clock by returning -EOPNOTSUPP. When userspace changes the guest's TOD clock, KVM updates its kvm.arch.epoch field and, in addition, the epoch field in all state descriptions of all VCPUs. But, under PV, the ultravisor will ignore the epoch field in the state description and simply overwrite it on next SIE exit with the actual guest epoch. This leads to KVM having an incorrect view of the guest's TOD clock: it has updated its internal kvm.arch.epoch field, but the ultravisor ignores the field in the state description. Whenever a guest is now waiting for a clock comparator, KVM will incorrectly calculate the time when the guest should wake up, possibly causing the guest to sleep for much longer than expected. With this change, kvm_s390_set_tod() will now take the kvm->lock to be able to call kvm_s390_pv_is_protected(). Since kvm_s390_set_tod_clock() also takes kvm->lock, use __kvm_s390_set_tod_clock() instead. The function kvm_s390_set_tod_clock is now unused, hence remove it. Update the documentation to indicate the TOD clock attr calls can now return -EOPNOTSUPP. Fixes: 0f3035047140 ("KVM: s390: protvirt: Do only reset registers that are accessible") Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20221011160712.928239-2-nrb@linux.ibm.com Message-Id: <20221011160712.928239-2-nrb@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-03-09Merge branch kvm-arm64/misc-5.18 into kvmarm-master/nextMarc Zyngier
* kvm-arm64/misc-5.18: : . : Misc fixes for KVM/arm64 5.18: : : - Drop unused kvm parameter to kvm_psci_version() : : - Implement CONFIG_DEBUG_LIST at EL2 : : - Make CONFIG_ARM64_ERRATUM_2077057 default y : : - Only do the interrupt dance if we have exited because of an interrupt : : - Remove traces of 32bit ARM host support from the documentation : . Documentation: KVM: Update documentation to indicate KVM is arm64-only KVM: arm64: Only open the interrupt window on exit due to an interrupt KVM: arm64: Enable Cortex-A510 erratum 2077057 by default Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-03-09Documentation: KVM: Update documentation to indicate KVM is arm64-onlyOliver Upton
KVM support for 32-bit ARM hosts (KVM/arm) has been removed from the kernel since commit 541ad0150ca4 ("arm: Remove 32bit KVM host support"). There still exists some remnants of the old architecture in the KVM documentation. Remove all traces of 32-bit host support from the documentation. Note that AArch32 guests are still supported. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220308172856.2997250-1-oupton@google.com
2022-02-08KVM: arm64: Refuse to run VCPU if the PMU doesn't match the physical CPUAlexandru Elisei
Userspace can assign a PMU to a VCPU with the KVM_ARM_VCPU_PMU_V3_SET_PMU device ioctl. If the VCPU is scheduled on a physical CPU which has a different PMU, the perf events needed to emulate a guest PMU won't be scheduled in and the guest performance counters will stop counting. Treat it as an userspace error and refuse to run the VCPU in this situation. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220127161759.53553-7-alexandru.elisei@arm.com
2022-02-08KVM: arm64: Add KVM_ARM_VCPU_PMU_V3_SET_PMU attributeAlexandru Elisei
When KVM creates an event and there are more than one PMUs present on the system, perf_init_event() will go through the list of available PMUs and will choose the first one that can create the event. The order of the PMUs in this list depends on the probe order, which can change under various circumstances, for example if the order of the PMU nodes change in the DTB or if asynchronous driver probing is enabled on the kernel command line (with the driver_async_probe=armv8-pmu option). Another consequence of this approach is that on heteregeneous systems all virtual machines that KVM creates will use the same PMU. This might cause unexpected behaviour for userspace: when a VCPU is executing on the physical CPU that uses this default PMU, PMU events in the guest work correctly; but when the same VCPU executes on another CPU, PMU events in the guest will suddenly stop counting. Fortunately, perf core allows user to specify on which PMU to create an event by using the perf_event_attr->type field, which is used by perf_init_event() as an index in the radix tree of available PMUs. Add the KVM_ARM_VCPU_PMU_V3_CTRL(KVM_ARM_VCPU_PMU_V3_SET_PMU) VCPU attribute to allow userspace to specify the arm_pmu that KVM will use when creating events for that VCPU. KVM will make no attempt to run the VCPU on the physical CPUs that share the PMU, leaving it up to userspace to manage the VCPU threads' affinity accordingly. To ensure that KVM doesn't expose an asymmetric system to the guest, the PMU set for one VCPU will be used by all other VCPUs. Once a VCPU has run, the PMU cannot be changed in order to avoid changing the list of available events for a VCPU, or to change the semantics of existing events. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220127161759.53553-6-alexandru.elisei@arm.com
2022-02-08KVM: arm64: Do not change the PMU event filter after a VCPU has runMarc Zyngier
Userspace can specify which events a guest is allowed to use with the KVM_ARM_VCPU_PMU_V3_FILTER attribute. The list of allowed events can be identified by a guest from reading the PMCEID{0,1}_EL0 registers. Changing the PMU event filter after a VCPU has run can cause reads of the registers performed before the filter is changed to return different values than reads performed with the new event filter in place. The architecture defines the two registers as read-only, and this behaviour contradicts that. Keep track when the first VCPU has run and deny changes to the PMU event filter to prevent this from happening. Signed-off-by: Marc Zyngier <maz@kernel.org> [ Alexandru E: Added commit message, updated ioctl documentation ] Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220127161759.53553-2-alexandru.elisei@arm.com
2021-10-18selftests: KVM: Introduce system counter offset testOliver Upton
Introduce a KVM selftest to verify that userspace manipulation of the TSC (via the new vCPU attribute) results in the correct behavior within the guest. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Oliver Upton <oupton@google.com> Message-Id: <20210916181555.973085-6-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18KVM: x86: Expose TSC offset controls to userspaceOliver Upton
To date, VMM-directed TSC synchronization and migration has been a bit messy. KVM has some baked-in heuristics around TSC writes to infer if the VMM is attempting to synchronize. This is problematic, as it depends on host userspace writing to the guest's TSC within 1 second of the last write. A much cleaner approach to configuring the guest's views of the TSC is to simply migrate the TSC offset for every vCPU. Offsets are idempotent, and thus not subject to change depending on when the VMM actually reads/writes values from/to KVM. The VMM can then read the TSC once with KVM_GET_CLOCK to capture a (realtime, host_tsc) pair at the instant when the guest is paused. Cc: David Matlack <dmatlack@google.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210916181538.968978-8-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30kvm: rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDSJuergen Gross
KVM_MAX_VCPU_ID is not specifying the highest allowed vcpu-id, but the number of allowed vcpu-ids. This has already led to confusion, so rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS to make its semantics more clear Suggested-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210913135745.13944-3-jgross@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-13Merge branch 'kvm-arm64/vlpi-save-restore' into kvmarm-master/nextMarc Zyngier
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-04-06docs: kvm: devices/arm-vgic-v3: enhance KVM_DEV_ARM_VGIC_CTRL_INIT docEric Auger
kvm_arch_vcpu_precreate() returns -EBUSY if the vgic is already initialized. So let's document that KVM_DEV_ARM_VGIC_CTRL_INIT must be called after all vcpu creations. Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405163941.510258-6-eric.auger@redhat.com
2021-03-24KVM: arm64: GICv4.1: Give a chance to save VLPI stateShenming Lu
Before GICv4.1, we don't have direct access to the VLPI state. So we simply let it fail early when encountering any VLPI in saving. But now we don't have to return -EACCES directly if on GICv4.1. Let’s change the hard code and give a chance to save the VLPI state (and preserve the UAPI). Signed-off-by: Shenming Lu <lushenming@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210322060158.1584-7-lushenming@huawei.com
2020-10-02KVM: arm64: Fix some documentation build warningsMauro Carvalho Chehab
As warned with make htmldocs: .../Documentation/virt/kvm/devices/vcpu.rst:70: WARNING: Malformed table. Text in column margin in table line 2. ======= ====================================================== -ENODEV: PMUv3 not supported or GIC not initialized -ENXIO: PMUv3 not properly configured or in-kernel irqchip not configured as required prior to calling this attribute -EBUSY: PMUv3 already initialized -EINVAL: Invalid filter range ======= ====================================================== The ':' character for two lines are above the size of the column. Besides that, other tables at the file doesn't use ':', so just drop them. While here, also fix this warning also introduced at the same patch: .../Documentation/virt/kvm/devices/vcpu.rst:88: WARNING: Block quote ends without a blank line; unexpected unindent. By marking the C code as a literal block. Fixes: 8be86a5eec04 ("KVM: arm64: Document PMU filtering API") Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/b5385dd0213f1f070667925bf7a807bf5270ba78.1601616399.git.mchehab+huawei@kernel.org
2020-09-29KVM: arm64: Match PMU error code descriptions with error conditionsAlexandru Elisei
Update the description of the PMU KVM_{GET, SET}_DEVICE_ATTR error codes to be a better match for the code that returns them. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Link: https://lore.kernel.org/r/20200924123731.268177-3-alexandru.elisei@arm.com
2020-09-29KVM: arm64: Add undocumented return values for PMU device control groupAlexandru Elisei
KVM_ARM_VCPU_PMU_V3_IRQ returns -EFAULT if get_user() fails when reading the interrupt number from kvm_device_attr.addr. KVM_ARM_VCPU_PMU_V3_INIT returns the error value from kvm_vgic_set_owner(). kvm_arm_pmu_v3_init() checks that the vgic has been initialized and the interrupt number is valid, but kvm_vgic_set_owner() can still return the error code -EEXIST if another device has already claimed the interrupt. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Link: https://lore.kernel.org/r/20200924123731.268177-2-alexandru.elisei@arm.com
2020-09-29KVM: arm64: Document PMU filtering APIMarc Zyngier
Add a small blurb describing how the event filtering API gets used. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-04-20docs: fix broken references to text filesMauro Carvalho Chehab
Several references got broken due to txt to ReST conversion. Several of them can be automatically fixed with: scripts/documentation-file-ref-check --fix Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> # hwtracing/coresight/Kconfig Reviewed-by: Paul E. McKenney <paulmck@kernel.org> # memory-barrier.txt Acked-by: Alex Shi <alex.shi@linux.alibaba.com> # translations/zh_CN Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> # translations/it_IT Acked-by: Marc Zyngier <maz@kernel.org> # kvm/arm64 Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/6f919ddb83a33b5f2a63b6b5f0575737bb2b36aa.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-02-27KVM: s390/interrupt: do not pin adapter interrupt pagesUlrich Weigand
The adapter interrupt page containing the indicator bits is currently pinned. That means that a guest with many devices can pin a lot of memory pages in the host. This also complicates the reference tracking which is needed for memory management handling of protected virtual machines. It might also have some strange side effects for madvise MADV_DONTNEED and other things. We can simply try to get the userspace page set the bits and free the page. By storing the userspace address in the irq routing entry instead of the guest address we can actually avoid many lookups and list walks so that this variant is very likely not slower. If userspace messes around with the memory slots the worst thing that can happen is that we write to some other memory within that process. As we get the the page with FOLL_WRITE this can also not be used to write to shared read-only pages. Signed-off-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> [borntraeger@de.ibm.com: patch simplification] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-02-12docs: kvm: convert devices/xive.txt to ReSTMauro Carvalho Chehab
- Use title markups; - adjust indentation and add blank lines as needed; - adjust tables to match ReST accepted formats; - mark code blocks as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/xics.txt to ReSTMauro Carvalho Chehab
- Use title markups; - adjust indentation and add blank lines as needed; - adjust tables to match ReST accepted formats; - use :field: markups. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/vm.txt to ReSTMauro Carvalho Chehab
- Use title markups; - adjust indentation and add blank lines as needed; - use :field: markups; - Use cross-references; - mark code blocks as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/vfio.txt to ReSTMauro Carvalho Chehab
- Use standard title markup; - adjust lists; - mark code blocks as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/vcpu.txt to ReSTMauro Carvalho Chehab
- Use title markups; - adjust indentation and add blank lines as needed; - adjust tables to match ReST accepted formats; - use :field: markups; - mark code blocks as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/s390_flic.txt to ReSTMauro Carvalho Chehab
- Use standard markup for document title; - Adjust indentation and add blank lines as needed; - use the notes markup; - mark code blocks as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/mpic.txt to ReSTMauro Carvalho Chehab
This document is almost in ReST format. The only thing needed is to mark a list as such and to add an extra whitespace. Yet, let's also use the standard document title markup, as it makes easier if anyone wants later to add sessions to it. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: convert devices/arm-vgit.txt to ReSTMauro Carvalho Chehab
- Use title markups; - change indent to match ReST syntax; - use proper table markups; - use literal block markups. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: devices/arm-vgit-v3.txt to ReSTMauro Carvalho Chehab
- Use title markups; - change indent to match ReST syntax; - use proper table markups; - use literal block markups. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-12docs: kvm: devices/arm-vgic-its.txt to ReST formatMauro Carvalho Chehab
- Fix document title to match ReST format - Convert the table to be properly recognized - use proper markups for literal blocks - Some indentation fixes to match ReST While here, add an index for kvm devices. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-21Merge tag 'kvmarm-5.5' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for Linux 5.5: - Allow non-ISV data aborts to be reported to userspace - Allow injection of data aborts from userspace - Expose stolen time to guests - GICv4 performance improvements - vgic ITS emulation fixes - Simplify FWB handling - Enable halt pool counters - Make the emulated timer PREEMPT_RT compliant Conflicts: include/uapi/linux/kvm.h