- 08 Jun, 2022 40 commits
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Chenyi Qiang authored
For the triple fault sythesized by KVM, e.g. the RSM path or nested_vmx_abort(), if KVM exits to userspace before the request is serviced, userspace could migrate the VM and lose the triple fault. Extend KVM_{G,S}ET_VCPU_EVENTS to support pending triple fault with a new event KVM_VCPUEVENT_VALID_FAULT_FAULT so that userspace can save and restore the triple fault event. This extension is guarded by a new KVM capability KVM_CAP_TRIPLE_FAULT_EVENT. Note that in the set_vcpu_events path, userspace is able to set/clear the triple fault request through triple_fault.pending field. Signed-off-by:Chenyi Qiang <chenyi.qiang@intel.com> Message-Id: <20220524135624.22988-2-chenyi.qiang@intel.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Like Xu authored
All gp or fixed counters have been reprogrammed using PERF_TYPE_RAW, which means that the table that maps perf_hw_id to event select values is no longer useful, at least for AMD. For Intel, the logic to check if the pmu event reported by Intel cpuid is not available is still required, in which case pmc_perf_hw_id() could be renamed to hw_event_is_unavail() and a bool value is returned to replace the semantics of "PERF_COUNT_HW_MAX+1". Signed-off-by:
Like Xu <likexu@tencent.com> Message-Id: <20220518132512.37864-12-likexu@tencent.com> Signed-off-by:
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Like Xu authored
With the help of perf_get_hw_event_config(), KVM could query the correct EVENTSEL_{EVENT, UMASK} pair of a kernel-generic hw event directly from the different *_perfmon_event_map[] by the kernel's pre-defined perf_hw_id. Also extend the bit range of the comparison field to AMD64_RAW_EVENT_MASK_NB to prevent AMD from defining EventSelect[11:8] into perfmon_event_map[] one day. Signed-off-by: -
Like Xu authored
Currently, we have [intel|knc|p4|p6]_perfmon_event_map on the Intel platforms and amd_[f17h]_perfmon_event_map on the AMD platforms. Early clumsy KVM code or other potential perf_event users may have hard-coded these perfmon_maps (e.g., arch/x86/kvm/svm/pmu.c), so it would not make sense to program a common hardware event based on the generic "enum perf_hw_id" once the two tables do not match. Let's provide an interface for callers outside the perf subsystem to get the counter config based on the perfmon_event_map currently in use, and it also helps to save bytes. Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Message-Id: <20220518132512.37864-10-likexu@tencent.com> Signed-off-by:
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Like Xu authored
The code sketch for reprogram_{gp, fixed}_counter() is similar, while the fixed counter using the PERF_TYPE_HARDWAR type and the gp being able to use either PERF_TYPE_HARDWAR or PERF_TYPE_RAW type depending on the pmc->eventsel value. After 'commit 76187563 ("KVM: x86/pmu: Setup pmc->eventsel for fixed PMCs")', the pmc->eventsel of the fixed counter will also have been setup with the same semantic value and will not be changed during the guest runtime. The original story of using the PERF_TYPE_HARDWARE type is to emulate guest architecture PMU on a host without architecture PMU (the Pentium 4), for which the guest vPMC needs to be reprogrammed using the kernel generic perf_hw_id. But essentially, "the HARDWARE is just a convenience wrapper over RAW IIRC", quoated from Peterz. So it could be pretty safe to use the PERF_TYPE_RAW type only in practice to program both gp and fixed counters naturally in the reprogram_counter(). To make the gp and fixed counters more semantically symmetrical, the selection of EVENTSEL_{USER, OS, INT} bits is temporarily translated via fixed_ctr_ctrl before the pmc_reprogram_counter() call. Cc: Peter Zijlstra <peterz@infradead.org> Suggested-by:Jim Mattson <jmattson@google.com> Signed-off-by:
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Paolo Bonzini authored
Since reprogram_counter(), reprogram_{gp, fixed}_counter() currently have the same incoming parameter "struct kvm_pmc *pmc", the callers can simplify the conetxt by using uniformly exported interface, which makes reprogram_ {gp, fixed}_counter() static and eliminates EXPORT_SYMBOL_GPL. Signed-off-by: -
Like Xu authored
Since afrer reprogram_fixed_counter() is called, it's bound to assign the requested fixed_ctr_ctrl to pmu->fixed_ctr_ctrl, this assignment step can be moved forward (the stale value for diff is saved extra early), thus simplifying the passing of parameters. No functional change intended. Signed-off-by:
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Like Xu authored
Because inside reprogram_gp_counter() it is bound to assign the requested eventel to pmc->eventsel, this assignment step can be moved forward, thus simplifying the passing of parameters to "struct kvm_pmc *pmc" only. No functional change intended. Signed-off-by:
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Like Xu authored
Passing the reference "struct kvm_pmc *pmc" when creating pmc->perf_event is sufficient. This change helps to simplify the calling convention by replacing reprogram_{gp, fixed}_counter() with reprogram_counter() seamlessly. No functional change intended. Signed-off-by: -
Like Xu authored
Checking the kvm->arch.pmu_event_filter policy in both gp and fixed code paths was somewhat redundant, so common parts can be extracted, which reduces code footprint and improves readability. Signed-off-by:
Wanpeng Li <wanpengli@tencent.com> Message-Id: <20220518132512.37864-3-likexu@tencent.com> Signed-off-by:
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Like Xu authored
The obsolete comment could more accurately state that AMD platforms have two base MSR addresses and two different maximum numbers for gp counters, depending on the X86_FEATURE_PERFCTR_CORE feature. Signed-off-by:
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Paolo Bonzini authored
Whenever an MSR is part of KVM_GET_MSR_INDEX_LIST, it has to be always retrievable and settable with KVM_GET_MSR and KVM_SET_MSR. Accept the PMU MSRs unconditionally in intel_is_valid_msr, if the access was host-initiated. Signed-off-by: -
Paolo Bonzini authored
Whenever an MSR is part of KVM_GET_MSR_INDEX_LIST, as is the case for MSR_IA32_DS_AREA, it has to be always settable with KVM_SET_MSR. Accept a zero value for these MSRs to obey the contract. Signed-off-by: -
Like Xu authored
MSR_CORE_PERF_GLOBAL_CTRL is introduced as part of Architecture PMU V2, as indicated by Intel SDM 19.2.2 and the intel_is_valid_msr() function. So in the absence of global_ctrl support, all PMCs are enabled as AMD does. Signed-off-by:
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Like Xu authored
Assigning a value to pmu->global_ctrl just to set the value of pmu->global_ctrl_mask is more readable but does not conform to the specification. The value is reset to zero on Power up and Reset but stays unchanged on INIT, like most other MSRs. Signed-off-by:
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Paolo Bonzini authored
Signed-off-by: -
Like Xu authored
Defining a static const array in a header file would introduce redundant definitions to the point of confusing semantics, and such a use case would only bring complaints from the compiler: arch/x86/kvm/pmu.h:20:32: warning: ‘vmx_icl_pebs_cpu’ defined but not used [-Wunused-const-variable=] 20 | static const struct x86_cpu_id vmx_icl_pebs_cpu[] = { | ^~~~~~~~~~~~~~~~ Fixes: a095df2c5f48 ("KVM: x86/pmu: Adjust precise_ip to emulate Ice Lake guest PDIR counter") Signed-off-by: -
Guo Zhengkui authored
Fix the following coccicheck warnings: tools/testing/selftests/kvm/lib/s390x/ucall.c:25:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/x86_64/ucall.c:27:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/riscv/ucall.c:56:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/aarch64/ucall.c:82:15-17: WARNING opportunity for min() tools/testing/selftests/kvm/lib/aarch64/ucall.c:55:20-21: WARNING opportunity for min() min() is defined in tools/include/linux/kernel.h. Signed-off-by:
Guo Zhengkui <guozhengkui@vivo.com> Acked-by:
Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by:
Anup Patel <anup@brainfault.org> Message-Id: <20220511120621.36956-1-guozhengkui@vivo.com> Signed-off-by:
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Like Xu authored
The CPUID features PDCM, DS and DTES64 are required for PEBS feature. KVM would expose CPUID feature PDCM, DS and DTES64 to guest when PEBS is supported in the KVM on the Ice Lake server platforms. Originally-by:
Andi Kleen <ak@linux.intel.com> Co-developed-by:
Kan Liang <kan.liang@linux.intel.com> Signed-off-by:
Luwei Kang <luwei.kang@intel.com> Signed-off-by:
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Like Xu authored
For the same purpose, the leagcy intel_pmu_lbr_is_compatible() can be renamed for reuse by more callers, and remove the comment about LBR use case can be deleted by the way. Signed-off-by:
Like Xu <like.xu@linux.intel.com> Acked-by:
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Like Xu authored
The information obtained from the interface perf_get_x86_pmu_capability() doesn't change, so an exported "struct x86_pmu_capability" is introduced for all guests in the KVM, and it's initialized before hardware_setup(). Signed-off-by:
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Like Xu authored
The guest PEBS will be disabled when some users try to perf KVM and its user-space through the same PEBS facility OR when the host perf doesn't schedule the guest PEBS counter in a one-to-one mapping manner (neither of these are typical scenarios). The PEBS records in the guest DS buffer are still accurate and the above two restrictions will be checked before each vm-entry only if guest PEBS is deemed to be enabled. Suggested-by:
Wei Wang <wei.w.wang@intel.com> Signed-off-by:
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Like Xu authored
It allows this inline function to be reused by more callers in more files, such as pmu_intel.c. Signed-off-by:
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Like Xu authored
The bit 12 represents "Processor Event Based Sampling Unavailable (RO)" : 1 = PEBS is not supported. 0 = PEBS is supported. A write to this PEBS_UNAVL available bit will bring #GP(0) when guest PEBS is enabled. Some PEBS drivers in guest may care about this bit. Signed-off-by:
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Like Xu authored
If IA32_PERF_CAPABILITIES.PEBS_BASELINE [bit 14] is set, the adaptive PEBS is supported. The PEBS_DATA_CFG MSR and adaptive record enable bits (IA32_PERFEVTSELx.Adaptive_Record and IA32_FIXED_CTR_CTRL. FCx_Adaptive_Record) are also supported. Adaptive PEBS provides software the capability to configure the PEBS records to capture only the data of interest, keeping the record size compact. An overflow of PMCx results in generation of an adaptive PEBS record with state information based on the selections specified in MSR_PEBS_DATA_CFG.By default, the record only contain the Basic group. When guest adaptive PEBS is enabled, the IA32_PEBS_ENABLE MSR will be added to the perf_guest_switch_msr() and switched during the VMX transitions just like CORE_PERF_GLOBAL_CTRL MSR. According to Intel SDM, software is recommended to PEBS Baseline when the following is true. IA32_PERF_CAPABILITIES.PEBS_BASELINE[14] && IA32_PERF_CAPABILITIES.PEBS_FMT[11:8] ≥ 4. Co-developed-by:
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Like Xu authored
When CPUID.01H:EDX.DS[21] is set, the IA32_DS_AREA MSR exists and points to the linear address of the first byte of the DS buffer management area, which is used to manage the PEBS records. When guest PEBS is enabled, the MSR_IA32_DS_AREA MSR will be added to the perf_guest_switch_msr() and switched during the VMX transitions just like CORE_PERF_GLOBAL_CTRL MSR. The WRMSR to IA32_DS_AREA MSR brings a #GP(0) if the source register contains a non-canonical address. Originally-by:
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Like Xu authored
The PEBS-PDIR facility on Ice Lake server is supported on IA31_FIXED0 only. If the guest configures counter 32 and PEBS is enabled, the PEBS-PDIR facility is supposed to be used, in which case KVM adjusts attr.precise_ip to 3 and request host perf to assign the exactly requested counter or fail. The CPU model check is also required since some platforms may place the PEBS-PDIR facility in another counter index. Signed-off-by:
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Like Xu authored
When a guest counter is configured as a PEBS counter through IA32_PEBS_ENABLE, a guest PEBS event will be reprogrammed by configuring a non-zero precision level in the perf_event_attr. The guest PEBS overflow PMI bit would be set in the guest GLOBAL_STATUS MSR when PEBS facility generates a PEBS overflow PMI based on guest IA32_DS_AREA MSR. Even with the same counter index and the same event code and mask, guest PEBS events will not be reused for non-PEBS events. Originally-by:
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Like Xu authored
If IA32_PERF_CAPABILITIES.PEBS_BASELINE [bit 14] is set, the IA32_PEBS_ENABLE MSR exists and all architecturally enumerated fixed and general-purpose counters have corresponding bits in IA32_PEBS_ENABLE that enable generation of PEBS records. The general-purpose counter bits start at bit IA32_PEBS_ENABLE[0], and the fixed counter bits start at bit IA32_PEBS_ENABLE[32]. When guest PEBS is enabled, the IA32_PEBS_ENABLE MSR will be added to the perf_guest_switch_msr() and atomically switched during the VMX transitions just like CORE_PERF_GLOBAL_CTRL MSR. Based on whether the platform supports x86_pmu.pebs_ept, it has also refactored the way to add more msrs to arr[] in intel_guest_get_msrs() for extensibility. Originally-by:
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Peter Zijlstra (Intel) authored
The value of pebs_counter_mask will be accessed frequently for repeated use in the intel_guest_get_msrs(). So it can be optimized instead of endlessly mucking about with branches. Signed-off-by:
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Like Xu authored
The mask value of fixed counter control register should be dynamic adjusted with the number of fixed counters. This patch introduces a variable that includes the reserved bits of fixed counter control registers. This is a generic code refactoring. Co-developed-by:
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Like Xu authored
On Intel platforms, the software can use the IA32_MISC_ENABLE[7] bit to detect whether the processor supports performance monitoring facility. It depends on the PMU is enabled for the guest, and a software write operation to this available bit will be ignored. The proposal to ignore the toggle in KVM is the way to go and that behavior matches bare metal. Signed-off-by:
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Like Xu authored
Splitting the logic for determining the guest values is unnecessarily confusing, and potentially fragile. Perf should have full knowledge and control of what values are loaded for the guest. If we change .guest_get_msrs() to take a struct kvm_pmu pointer, then it can generate the full set of guest values by grabbing guest ds_area and pebs_data_cfg. Alternatively, .guest_get_msrs() could take the desired guest MSR values directly (ds_area and pebs_data_cfg), but kvm_pmu is vendor agnostic, so we don't see any reason to not just pass the pointer. Suggested-by:
Sean Christopherson <seanjc@google.com> Signed-off-by:
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Like Xu authored
With PEBS virtualization, the guest PEBS records get delivered to the guest DS, and the host pmi handler uses perf_guest_cbs->is_in_guest() to distinguish whether the PMI comes from the guest code like Intel PT. No matter how many guest PEBS counters are overflowed, only triggering one fake event is enough. The fake event causes the KVM PMI callback to be called, thereby injecting the PEBS overflow PMI into the guest. KVM may inject the PMI with BUFFER_OVF set, even if the guest DS is empty. That should really be harmless. Thus guest PEBS handler would retrieve the correct information from its own PEBS records buffer. Cc: linux-perf-users@vger.kernel.org Originally-by:
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Like Xu authored
Add support for EPT-Friendly PEBS, a new CPU feature that enlightens PEBS to translate guest linear address through EPT, and facilitates handling VM-Exits that occur when accessing PEBS records. More information can be found in the December 2021 release of Intel's SDM, Volume 3, 18.9.5 "EPT-Friendly PEBS". This new hardware facility makes sure the guest PEBS records will not be lost, which is available on Intel Ice Lake Server platforms (and later). KVM will check this field through perf_get_x86_pmu_capability() instead of hard coding the CPU models in the KVM code. If it is supported, the guest PEBS capability will be exposed to the guest. Guest PEBS can be enabled when and only when "EPT-Friendly PEBS" is supported and EPT is enabled. Cc: linux-perf-users@vger.kernel.org Signed-off-by:
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Chao Gao authored
With IPI virtualization enabled, the processor emulates writes to APIC registers that would send IPIs. The processor sets the bit corresponding to the vector in target vCPU's PIR and may send a notification (IPI) specified by NDST and NV fields in target vCPU's Posted-Interrupt Descriptor (PID). It is similar to what IOMMU engine does when dealing with posted interrupt from devices. A PID-pointer table is used by the processor to locate the PID of a vCPU with the vCPU's APIC ID. The table size depends on maximum APIC ID assigned for current VM session from userspace. Allocating memory for PID-pointer table is deferred to vCPU creation, because irqchip mode and VM-scope maximum APIC ID is settled at that point. KVM can skip PID-pointer table allocation if !irqchip_in_kernel(). Like VT-d PI, if a vCPU goes to blocked state, VMM needs to switch its notification vector to wakeup vector. This can ensure that when an IPI for blocked vCPUs arrives, VMM can get control and wake up blocked vCPUs. And if a VCPU is preempted, its posted interrupt notification is suppressed. Note that IPI virtualization can only virualize physical-addressing, flat mode, unicast IPIs. Sending other IPIs would still cause a trap-like APIC-write VM-exit and need to be handled by VMM. Signed-off-by:
Chao Gao <chao.gao@intel.com> Signed-off-by:
Zeng Guang <guang.zeng@intel.com> Message-Id: <20220419154510.11938-1-guang.zeng@intel.com> Signed-off-by:
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Zeng Guang authored
Basic test coverage of KVM_CAP_MAX_VCPU_ID cap. This capability can be enabled before vCPU creation and only allowed to set once. if assigned vcpu id is beyond KVM_CAP_MAX_VCPU_ID capability, vCPU creation will fail. Signed-off-by:
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Zeng Guang authored
Introduce new max_vcpu_ids in KVM for x86 architecture. Userspace can assign maximum possible vcpu id for current VM session using KVM_CAP_MAX_VCPU_ID of KVM_ENABLE_CAP ioctl(). This is done for x86 only because the sole use case is to guide memory allocation for PID-pointer table, a structure needed to enable VMX IPI. By default, max_vcpu_ids set as KVM_MAX_VCPU_IDS. Suggested-by:
Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by:
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Zeng Guang authored
kvm_arch_vcpu_precreate() targets to handle arch specific VM resource to be prepared prior to the actual creation of vCPU. For example, x86 platform may need do per-VM allocation based on max_vcpu_ids at the first vCPU creation. It probably leads to concurrency control on this allocation as multiple vCPU creation could happen simultaneously. From the architectual point of view, it's necessary to execute kvm_arch_vcpu_precreate() under protect of kvm->lock. Currently only arm64, x86 and s390 have non-nop implementations at the stage of vCPU pre-creation. Remove the lock acquiring in s390's design and make sure all architecture can run kvm_arch_vcpu_precreate() safely under kvm->lock without recrusive lock issue. Suggested-by:
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Zeng Guang authored
Remove the condition check cpu_has_secondary_exec_ctrls(). Calling vmx_refresh_apicv_exec_ctrl() premises secondary controls activated and VMCS fields related to APICv valid as well. If it's invoked in wrong circumstance at the worst case, VMX operation will report VMfailValid error without further harmful impact and just functions as if all the secondary controls were 0. Suggested-by:
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