KVM: x86: Introduce "struct kvm_caps" to track misc caps/settings
Add kvm_caps to hold a variety of capabilites and defaults that aren't
handled by kvm_cpu_caps because they aren't CPUID bits in order to reduce
the amount of boilerplate code required to add a new feature. The vast
majority (all?) of the caps interact with vendor code and are written
only during initialization, i.e. should be tagged __read_mostly, declared
extern in x86.h, and exported.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220524135624.22988-4-chenyi.qiang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Chenyi Qiang [Tue, 24 May 2022 13:56:22 +0000 (21:56 +0800)]
KVM: selftests: Add a test to get/set triple fault event
Add a selftest for triple fault event:
- launch the L2 and exit to userspace via I/O.
- using KVM_SET_VCPU_EVENTS to pend a triple fault event.
- with the immediate_exit, check the triple fault is pending.
- run for real with pending triple fault and L1 can see the triple
fault.
Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20220524135624.22988-3-chenyi.qiang@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Chenyi Qiang [Tue, 24 May 2022 13:56:21 +0000 (21:56 +0800)]
KVM: x86: Extend KVM_{G,S}ET_VCPU_EVENTS to support pending triple fault
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>
Like Xu [Wed, 18 May 2022 13:25:12 +0000 (21:25 +0800)]
KVM: x86/pmu: Drop amd_event_mapping[] in the KVM context
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: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:11 +0000 (21:25 +0800)]
KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config()
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 <likexu@tencent.com>
Message-Id: <20220518132512.37864-11-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:10 +0000 (21:25 +0800)]
perf: x86/core: Add interface to query perfmon_event_map[] directly
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: Like Xu <likexu@tencent.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220518132512.37864-10-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:09 +0000 (21:25 +0800)]
KVM: x86/pmu: Use PERF_TYPE_RAW to merge reprogram_{gp,fixed}counter()
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 a920262b9a2d ("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: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-9-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 25 May 2022 09:28:56 +0000 (05:28 -0400)]
KVM: x86/pmu: Use only the uniform interface reprogram_counter()
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 <likexu@tencent.com>
Message-Id: <20220518132512.37864-8-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:07 +0000 (21:25 +0800)]
KVM: x86/pmu: Drop "u8 ctrl, int idx" for reprogram_fixed_counter()
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: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-7-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:06 +0000 (21:25 +0800)]
KVM: x86/pmu: Drop "u64 eventsel" for reprogram_gp_counter()
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: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-6-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:05 +0000 (21:25 +0800)]
KVM: x86/pmu: Pass only "struct kvm_pmc *pmc" to reprogram_counter()
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 <likexu@tencent.com>
Message-Id: <20220518132512.37864-5-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:03 +0000 (21:25 +0800)]
KVM: x86/pmu: Extract check_pmu_event_filter() handling both GP and fixed counters
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: Like Xu <likexu@tencent.com> Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <20220518132512.37864-3-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 13:25:02 +0000 (21:25 +0800)]
KVM: x86/pmu: Update comments for AMD gp counters
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: Like Xu <likexu@tencent.com>
Message-Id: <20220518132512.37864-2-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Wed, 25 May 2022 08:39:22 +0000 (04:39 -0400)]
KVM: x86: always allow host-initiated writes to PMU MSRs
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 <pbonzini@redhat.com>
Paolo Bonzini [Wed, 1 Jun 2022 07:21:19 +0000 (03:21 -0400)]
KVM: vmx, pmu: accept 0 for host-initiated write to MSR_IA32_DS_AREA
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: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Tue, 10 May 2022 04:44:07 +0000 (12:44 +0800)]
KVM: x86/pmu: Don't overwrite the pmu->global_ctrl when refreshing
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: Like Xu <likexu@tencent.com>
Message-Id: <20220510044407.26445-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Wed, 18 May 2022 17:01:16 +0000 (01:01 +0800)]
KVM: x86/pmu: Move the vmx_icl_pebs_cpu[] definition out of the header file
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: Like Xu <likexu@tencent.com>
Message-Id: <20220518170118.66263-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Guo Zhengkui [Wed, 11 May 2022 12:05:55 +0000 (20:05 +0800)]
selftests: kvm: replace ternary operator with min()
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()
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: Kan Liang <kan.liang@linux.intel.com> Co-developed-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220411101946.20262-18-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:45 +0000 (18:19 +0800)]
KVM: x86/cpuid: Refactor host/guest CPU model consistency check
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: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-17-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:44 +0000 (18:19 +0800)]
KVM: x86/pmu: Add kvm_pmu_cap to optimize perf_get_x86_pmu_capability
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: Like Xu <likexu@tencent.com>
Message-Id: <20220411101946.20262-16-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:43 +0000 (18:19 +0800)]
KVM: x86/pmu: Disable guest PEBS temporarily in two rare situations
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: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-15-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:42 +0000 (18:19 +0800)]
KVM: x86/pmu: Move pmc_speculative_in_use() to arch/x86/kvm/pmu.h
It allows this inline function to be reused by more callers in
more files, such as pmu_intel.c.
Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-14-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:41 +0000 (18:19 +0800)]
KVM: x86: Set PEBS_UNAVAIL in IA32_MISC_ENABLE when PEBS is enabled
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: Like Xu <like.xu@linux.intel.com>
Message-Id: <20220411101946.20262-13-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:40 +0000 (18:19 +0800)]
KVM: x86/pmu: Add PEBS_DATA_CFG MSR emulation to support adaptive PEBS
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: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220411101946.20262-12-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:39 +0000 (18:19 +0800)]
KVM: x86/pmu: Add IA32_DS_AREA MSR emulation to support guest DS
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: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-11-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:38 +0000 (18:19 +0800)]
KVM: x86/pmu: Adjust precise_ip to emulate Ice Lake guest PDIR counter
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: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-10-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:37 +0000 (18:19 +0800)]
KVM: x86/pmu: Reprogram PEBS event to emulate guest PEBS counter
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: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Like Xu <likexu@tencent.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-9-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:36 +0000 (18:19 +0800)]
KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS
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: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Co-developed-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-8-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86/perf/core: Add pebs_capable to store valid PEBS_COUNTER_MASK value
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: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-7-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:34 +0000 (18:19 +0800)]
KVM: x86/pmu: Introduce the ctrl_mask value for fixed counter
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: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Luwei Kang <luwei.kang@intel.com> Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-6-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:33 +0000 (18:19 +0800)]
KVM: x86/pmu: Set MSR_IA32_MISC_ENABLE_EMON bit when vPMU is enabled
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: Like Xu <likexu@tencent.com>
Message-Id: <20220411101946.20262-5-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:32 +0000 (18:19 +0800)]
perf/x86/core: Pass "struct kvm_pmu *" to determine the guest values
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: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Message-Id: <20220411101946.20262-4-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:31 +0000 (18:19 +0800)]
perf/x86/intel: Handle guest PEBS overflow PMI for KVM guest
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: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220411101946.20262-3-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Like Xu [Mon, 11 Apr 2022 10:19:30 +0000 (18:19 +0800)]
perf/x86/intel: Add EPT-Friendly PEBS for Ice Lake Server
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: Like Xu <likexu@tencent.com>
Message-Id: <20220411101946.20262-2-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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.
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: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220422134456.26655-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Allow userspace to set maximum VCPU id for VM
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: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419154444.11888-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: Move kvm_arch_vcpu_precreate() under kvm->lock
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: Sean Christopherson <seanjc@google.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419154409.11842-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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: Sean Christopherson <seanjc@google.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419153604.11786-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Add support for vICR APIC-write VM-Exits in x2APIC mode
Upcoming Intel CPUs will support virtual x2APIC MSR writes to the vICR,
i.e. will trap and generate an APIC-write VM-Exit instead of intercepting
the WRMSR. Add support for handling "nodecode" x2APIC writes, which
were previously impossible.
Note, x2APIC MSR writes are 64 bits wide.
Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419153516.11739-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Robert Hoo [Tue, 19 Apr 2022 15:34:41 +0000 (23:34 +0800)]
KVM: VMX: Report tertiary_exec_control field in dump_vmcs()
Add tertiary_exec_control field report in dump_vmcs(). Meanwhile,
reorganize the dump output of VMCS category as follows.
Before change:
*** Control State ***
PinBased=0x000000ff CPUBased=0xb5a26dfa SecondaryExec=0x061037eb
EntryControls=0000d1ff ExitControls=002befff
After change:
*** Control State ***
CPUBased=0xb5a26dfa SecondaryExec=0x061037eb TertiaryExec=0x0000000000000010
PinBased=0x000000ff EntryControls=0000d1ff ExitControls=002befff
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419153441.11687-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Robert Hoo [Tue, 19 Apr 2022 15:34:00 +0000 (23:34 +0800)]
KVM: VMX: Detect Tertiary VM-Execution control when setup VMCS config
Check VMX features on tertiary execution control in VMCS config setup.
Sub-features in tertiary execution control to be enabled are adjusted
according to hardware capabilities although no sub-feature is enabled
in this patch.
EVMCSv1 doesn't support tertiary VM-execution control, so disable it
when EVMCSv1 is in use. And define the auxiliary functions for Tertiary
control field here, using the new BUILD_CONTROLS_SHADOW().
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419153400.11642-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Robert Hoo [Tue, 19 Apr 2022 15:33:18 +0000 (23:33 +0800)]
KVM: VMX: Extend BUILD_CONTROLS_SHADOW macro to support 64-bit variation
The Tertiary VM-Exec Control, different from previous control fields, is 64
bit. So extend BUILD_CONTROLS_SHADOW() by adding a 'bit' parameter, to
support both 32 bit and 64 bit fields' auxiliary functions building.
Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419153318.11595-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Robert Hoo [Tue, 19 Apr 2022 15:32:40 +0000 (23:32 +0800)]
x86/cpu: Add new VMX feature, Tertiary VM-Execution control
A new 64-bit control field "tertiary processor-based VM-execution
controls", is defined [1]. It's controlled by bit 17 of the primary
processor-based VM-execution controls.
Different from its brother VM-execution fields, this tertiary VM-
execution controls field is 64 bit. So it occupies 2 vmx_feature_leafs,
TERTIARY_CTLS_LOW and TERTIARY_CTLS_HIGH.
Its companion VMX capability reporting MSR,MSR_IA32_VMX_PROCBASED_CTLS3
(0x492), is also semantically different from its brothers, whose 64 bits
consist of all allow-1, rather than 32-bit allow-0 and 32-bit allow-1 [1][2].
Therefore, its init_vmx_capabilities() is a little different from others.
[1] ISE 6.2 "VMCS Changes"
https://www.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html
[2] SDM Vol3. Appendix A.3
Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Robert Hoo <robert.hu@linux.intel.com> Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Message-Id: <20220419153240.11549-1-guang.zeng@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Comment FNAME(sync_page) to document TLB flushing logic
Add a comment to FNAME(sync_page) to explain why the TLB flushing logic
conspiculously doesn't handle the scenario of guest protections being
reduced. Specifically, if synchronizing a SPTE drops execute protections,
KVM will not emit a TLB flush, whereas dropping writable or clearing A/D
bits does trigger a flush via mmu_spte_update(). Architecturally, until
the GPTE is implicitly or explicitly flushed from the guest's perspective,
KVM is not required to flush any old, stale translations.
Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220513195000.99371-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86/mmu: Drop RWX=0 SPTEs during ept_sync_page()
All of sync_page()'s existing checks filter out only !PRESENT gPTE,
because without execute-only, all upper levels are guaranteed to be at
least READABLE. However, if EPT with execute-only support is in use by
L1, KVM can create an SPTE that is shadow-present but guest-inaccessible
(RWX=0) if the upper level combined permissions are R (or RW) and
the leaf EPTE is changed from R (or RW) to X. Because the EPTE is
considered present when viewed in isolation, and no reserved bits are set,
FNAME(prefetch_invalid_gpte) will consider the GPTE valid, and cause a
not-present SPTE to be created.
The SPTE is "correct": the guest translation is inaccessible because
the combined protections of all levels yield RWX=0, and KVM will just
redirect any vmexits to the guest. If EPT A/D bits are disabled, KVM
can mistake the SPTE for an access-tracked SPTE, but again such confusion
isn't fatal, as the "saved" protections are also RWX=0. However,
creating a useless SPTE in general means that KVM messed up something,
even if this particular goof didn't manifest as a functional bug.
So, drop SPTEs whose new protections will yield a RWX=0 SPTE, and
add a WARN in make_spte() to detect creation of SPTEs that will
result in RWX=0 protections.
Fixes: cf578f190f1c ("kvm: mmu: track read permission explicitly for shadow EPT page tables") Cc: David Matlack <dmatlack@google.com> Cc: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220513195000.99371-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a KVM self-test that checks whether a nSVM L1 is able to successfully
inject a software interrupt, a soft exception and a NMI into its L2 guest.
In practice, this tests both the next_rip field consistency and
L1-injected event with intervening L0 VMEXIT during its delivery:
the first nested VMRUN (that's also trying to inject a software interrupt)
will immediately trigger a L0 NPF.
This L0 NPF will have zero in its CPU-returned next_rip field, which if
incorrectly reused by KVM will trigger a #PF when trying to return to
such address 0 from the interrupt handler.
For NMI injection this tests whether the L1 NMI state isn't getting
incorrectly mixed with the L2 NMI state if a L1 -> L2 NMI needs to be
re-injected.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
[sean: check exact L2 RIP on first soft interrupt] Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <d5f3d56528558ad8e28a9f1e1e4187f5a1e6770a.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A NMI that L1 wants to inject into its L2 should be directly re-injected,
without causing L0 side effects like engaging NMI blocking for L1.
It's also worth noting that in this case it is L1 responsibility
to track the NMI window status for its L2 guest.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <f894d13501cd48157b3069a4b4c7369575ddb60e.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: x86: Differentiate Soft vs. Hard IRQs vs. reinjected in tracepoint
In the IRQ injection tracepoint, differentiate between Hard IRQs and Soft
"IRQs", i.e. interrupts that are reinjected after incomplete delivery of
a software interrupt from an INTn instruction. Tag reinjected interrupts
as such, even though the information is usually redundant since soft
interrupts are only ever reinjected by KVM. Though rare in practice, a
hard IRQ can be reinjected.
Signed-off-by: Sean Christopherson <seanjc@google.com>
[MSS: change "kvm_inj_virq" event "reinjected" field type to bool] Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <9664d49b3bd21e227caa501cff77b0569bebffe2.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Print the error code in the exception injection tracepoint if and only if
the exception has an error code. Define the entire error code sequence
as a set of formatted strings, print empty strings if there's no error
code, and abuse __print_symbolic() by passing it an empty array to coerce
it into printing the error code as a hex string.
Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <e8f0511733ed2a0410cbee8a0a7388eac2ee5bac.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Trace exceptions that are re-injected, not just those that KVM is
injecting for the first time. Debugging re-injection bugs is painful
enough as is, not having visibility into what KVM is doing only makes
things worse.
Delay propagating pending=>injected in the non-reinjection path so that
the tracing can properly identify reinjected exceptions.
Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <25470690a38b4d2b32b6204875dd35676c65c9f2.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: SVM: Re-inject INTn instead of retrying the insn on "failure"
Re-inject INTn software interrupts instead of retrying the instruction if
the CPU encountered an intercepted exception while vectoring the INTn,
e.g. if KVM intercepted a #PF when utilizing shadow paging. Retrying the
instruction is architecturally wrong e.g. will result in a spurious #DB
if there's a code breakpoint on the INT3/O, and lack of re-injection also
breaks nested virtualization, e.g. if L1 injects a software interrupt and
vectoring the injected interrupt encounters an exception that is
intercepted by L0 but not L1.
Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <1654ad502f860948e4f2d57b8bd881d67301f785.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction
Re-inject INT3/INTO instead of retrying the instruction if the CPU
encountered an intercepted exception while vectoring the software
exception, e.g. if vectoring INT3 encounters a #PF and KVM is using
shadow paging. Retrying the instruction is architecturally wrong, e.g.
will result in a spurious #DB if there's a code breakpoint on the INT3/O,
and lack of re-injection also breaks nested virtualization, e.g. if L1
injects a software exception and vectoring the injected exception
encounters an exception that is intercepted by L0 but not L1.
Due to, ahem, deficiencies in the SVM architecture, acquiring the next
RIP may require flowing through the emulator even if NRIPS is supported,
as the CPU clears next_rip if the VM-Exit is due to an exception other
than "exceptions caused by the INT3, INTO, and BOUND instructions". To
deal with this, "skip" the instruction to calculate next_rip (if it's
not already known), and then unwind the RIP write and any side effects
(RFLAGS updates).
Save the computed next_rip and use it to re-stuff next_rip if injection
doesn't complete. This allows KVM to do the right thing if next_rip was
known prior to injection, e.g. if L1 injects a soft event into L2, and
there is no backing INTn instruction, e.g. if L1 is injecting an
arbitrary event.
Note, it's impossible to guarantee architectural correctness given SVM's
architectural flaws. E.g. if the guest executes INTn (no KVM injection),
an exit occurs while vectoring the INTn, and the guest modifies the code
stream while the exit is being handled, KVM will compute the incorrect
next_rip due to "skipping" the wrong instruction. A future enhancement
to make this less awful would be for KVM to detect that the decoded
instruction is not the correct INTn and drop the to-be-injected soft
event (retrying is a lesser evil compared to shoving the wrong RIP on the
exception stack).
Reported-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <65cb88deab40bc1649d509194864312a89bbe02e.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: SVM: Stuff next_rip on emulated INT3 injection if NRIPS is supported
If NRIPS is supported in hardware but disabled in KVM, set next_rip to
the next RIP when advancing RIP as part of emulating INT3 injection.
There is no flag to tell the CPU that KVM isn't using next_rip, and so
leaving next_rip is left as is will result in the CPU pushing garbage
onto the stack when vectoring the injected event.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Fixes: 397076fd8c2e ("KVM: SVM: Emulate nRIP feature when reinjecting INT3") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <cd328309a3b88604daa2359ad56f36cb565ce2d4.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: SVM: Unwind "speculative" RIP advancement if INTn injection "fails"
Unwind the RIP advancement done by svm_queue_exception() when injecting
an INT3 ultimately "fails" due to the CPU encountering a VM-Exit while
vectoring the injected event, even if the exception reported by the CPU
isn't the same event that was injected. If vectoring INT3 encounters an
exception, e.g. #NP, and vectoring the #NP encounters an intercepted
exception, e.g. #PF when KVM is using shadow paging, then the #NP will
be reported as the event that was in-progress.
Note, this is still imperfect, as it will get a false positive if the
INT3 is cleanly injected, no VM-Exit occurs before the IRET from the INT3
handler in the guest, the instruction following the INT3 generates an
exception (directly or indirectly), _and_ vectoring that exception
encounters an exception that is intercepted by KVM. The false positives
could theoretically be solved by further analyzing the vectoring event,
e.g. by comparing the error code against the expected error code were an
exception to occur when vectoring the original injected exception, but
SVM without NRIPS is a complete disaster, trying to make it 100% correct
is a waste of time.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Fixes: 397076fd8c2e ("KVM: SVM: Emulate nRIP feature when reinjecting INT3") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <450133cf0a026cb9825a2ff55d02cb136a1cb111.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: SVM: Don't BUG if userspace injects an interrupt with GIF=0
Don't BUG/WARN on interrupt injection due to GIF being cleared,
since it's trivial for userspace to force the situation via
KVM_SET_VCPU_EVENTS (even if having at least a WARN there would be correct
for KVM internally generated injections).
KVM: nSVM: Sync next_rip field from vmcb12 to vmcb02
The next_rip field of a VMCB is *not* an output-only field for a VMRUN.
This field value (instead of the saved guest RIP) in used by the CPU for
the return address pushed on stack when injecting a software interrupt or
INT3 or INTO exception.
Make sure this field gets synced from vmcb12 to vmcb02 when entering L2 or
loading a nested state and NRIPS is exposed to L1. If NRIPS is supported
in hardware but not exposed to L1 (nrips=0 or hidden by userspace), stuff
vmcb02's next_rip from the new L2 RIP to emulate a !NRIPS CPU (which
saves RIP on the stack as-is).
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <c2e0a3d78db3ae30530f11d4e9254b452a89f42b.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Maxim Levitsky [Mon, 6 Jun 2022 18:11:49 +0000 (21:11 +0300)]
KVM: SVM: fix tsc scaling cache logic
SVM uses a per-cpu variable to cache the current value of the
tsc scaling multiplier msr on each cpu.
Commit 3b05675ac7460
("KVM: X86: Add vendor callbacks for writing the TSC multiplier")
broke this caching logic.
Refactor the code so that all TSC scaling multiplier writes go through
a single function which checks and updates the cache.
This fixes the following scenario:
1. A CPU runs a guest with some tsc scaling ratio.
2. New guest with different tsc scaling ratio starts on this CPU
and terminates almost immediately.
This ensures that the short running guest had set the tsc scaling ratio just
once when it was set via KVM_SET_TSC_KHZ. Due to the bug,
the per-cpu cache is not updated.
3. The original guest continues to run, it doesn't restore the msr
value back to its own value, because the cache matches,
and thus continues to run with a wrong tsc scaling ratio.
Fixes: 3b05675ac7460 ("KVM: X86: Add vendor callbacks for writing the TSC multiplier") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220606181149.103072-1-mlevitsk@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM: selftests: Make hyperv_clock selftest more stable
hyperv_clock doesn't always give a stable test result, especially with
AMD CPUs. The test compares Hyper-V MSR clocksource (acquired either
with rdmsr() from within the guest or KVM_GET_MSRS from the host)
against rdtsc(). To increase the accuracy, increase the measured delay
(done with nop loop) by two orders of magnitude and take the mean rdtsc()
value before and after rdmsr()/KVM_GET_MSRS.
Ben Gardon [Wed, 25 May 2022 23:09:04 +0000 (23:09 +0000)]
KVM: x86/MMU: Zap non-leaf SPTEs when disabling dirty logging
Currently disabling dirty logging with the TDP MMU is extremely slow.
On a 96 vCPU / 96G VM backed with gigabyte pages, it takes ~200 seconds
to disable dirty logging with the TDP MMU, as opposed to ~4 seconds with
the shadow MMU.
When disabling dirty logging, zap non-leaf parent entries to allow
replacement with huge pages instead of recursing and zapping all of the
child, leaf entries. This reduces the number of TLB flushes required.
and reduces the disable dirty log time with the TDP MMU to ~3 seconds.
Opportunistically add a WARN() to catch GFNs that are mapped at a
higher level than their max level.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20220525230904.1584480-1-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Jan Beulich [Tue, 7 Jun 2022 15:00:53 +0000 (17:00 +0200)]
x86: drop bogus "cc" clobber from __try_cmpxchg_user_asm()
As noted (and fixed) a couple of times in the past, "=@cc<cond>" outputs
and clobbering of "cc" don't work well together. The compiler appears to
mean to reject such, but doesn't - in its upstream form - quite manage
to yet for "cc". Furthermore two similar macros don't clobber "cc", and
clobbering "cc" is pointless in asm()-s for x86 anyway - the compiler
always assumes status flags to be clobbered there.
Fixes: 3c75cc27a67d ("x86/uaccess: Implement macros for CMPXCHG on user addresses") Signed-off-by: Jan Beulich <jbeulich@suse.com>
Message-Id: <485c0c0b-a3a7-0b7c-5264-7d00c01de032@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Seth Forshee [Wed, 4 May 2022 18:08:40 +0000 (13:08 -0500)]
entry/kvm: Exit to user mode when TIF_NOTIFY_SIGNAL is set
A livepatch transition may stall indefinitely when a kvm vCPU is heavily
loaded. To the host, the vCPU task is a user thread which is spending a
very long time in the ioctl(KVM_RUN) syscall. During livepatch
transition, set_notify_signal() will be called on such tasks to
interrupt the syscall so that the task can be transitioned. This
interrupts guest execution, but when xfer_to_guest_mode_work() sees that
TIF_NOTIFY_SIGNAL is set but not TIF_SIGPENDING it concludes that an
exit to user mode is unnecessary, and guest execution is resumed without
transitioning the task for the livepatch.
This handling of TIF_NOTIFY_SIGNAL is incorrect, as set_notify_signal()
is expected to break tasks out of interruptible kernel loops and cause
them to return to userspace. Change xfer_to_guest_mode_work() to handle
TIF_NOTIFY_SIGNAL the same as TIF_SIGPENDING, signaling to the vCPU run
loop that an exit to userpsace is needed. Any pending task_work will be
run when get_signal() is called from exit_to_user_mode_loop(), so there
is no longer any need to run task work from xfer_to_guest_mode_work().
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Seth Forshee <sforshee@digitalocean.com>
Message-Id: <20220504180840.2907296-1-sforshee@digitalocean.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A KVM device cleanup happens in either of two callbacks:
1) destroy() which is called when the VM is being destroyed;
2) release() which is called when a device fd is closed.
Most KVM devices use 1) but Book3s's interrupt controller KVM devices
(XICS, XIVE, XIVE-native) use 2) as they need to close and reopen during
the machine execution. The error handling in kvm_ioctl_create_device()
assumes destroy() is always defined which leads to NULL dereference as
discovered by Syzkaller.
This adds a checks for destroy!=NULL and adds a missing release().
This is not changing kvm_destroy_devices() as devices with defined
release() should have been removed from the KVM devices list by then.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linus Torvalds [Mon, 6 Jun 2022 00:14:03 +0000 (17:14 -0700)]
Merge tag 'pull-work.fd-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull file descriptor fix from Al Viro:
"Fix for breakage in #work.fd this window"
* tag 'pull-work.fd-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix the breakage in close_fd_get_file() calling conventions change
Linus Torvalds [Sun, 5 Jun 2022 18:51:48 +0000 (11:51 -0700)]
bluetooth: don't use bitmaps for random flag accesses
The bluetooth code uses our bitmap infrastructure for the two bits (!)
of connection setup flags, and in the process causes odd problems when
it converts between a bitmap and just the regular values of said bits.
It's completely pointless to do things like bitmap_to_arr32() to convert
a bitmap into a u32. It shoudln't have been a bitmap in the first
place. The reason to use bitmaps is if you have arbitrary number of
bits you want to manage (not two!), or if you rely on the atomicity
guarantees of the bitmap setting and clearing.
The code could use an "atomic_t" and use "atomic_or/andnot()" to set and
clear the bit values, but considering that it then copies the bitmaps
around with "bitmap_to_arr32()" and friends, there clearly cannot be a
lot of atomicity requirements.
So just use a regular integer.
In the process, this avoids the warnings about erroneous use of
bitmap_from_u64() which were triggered on 32-bit architectures when
conversion from a u64 would access two words (and, surprise, surprise,
only one word is needed - and indeed overkill - for a 2-bit bitmap).
That was always problematic, but the compiler seems to notice it and
warn about the invalid pattern only after commit a1a19b185fa0 ("lib: add
bitmap_{from,to}_arr64") changed the exact implementation details of
'bitmap_from_u64()', as reported by Sudip Mukherjee and Stephen Rothwell.
Al Viro [Sun, 5 Jun 2022 18:01:42 +0000 (14:01 -0400)]
fix the breakage in close_fd_get_file() calling conventions change
It used to grab an extra reference to struct file rather than
just transferring to caller the one it had removed from descriptor
table. New variant doesn't, and callers need to be adjusted.
Reported-and-tested-by: syzbot+47dd250f527cb7bebf24@syzkaller.appspotmail.com Fixes: 8d392c99b321 ("Unify the primitives for file descriptor closing") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Linus Torvalds [Sun, 5 Jun 2022 18:00:43 +0000 (11:00 -0700)]
Merge tag 'x86-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX fix from Thomas Gleixner:
"A single fix for x86/SGX to prevent that memory which is allocated for
an SGX enclave is accounted to the wrong memory control group"
* tag 'x86-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sgx: Set active memcg prior to shmem allocation
Linus Torvalds [Sun, 5 Jun 2022 17:55:23 +0000 (10:55 -0700)]
Merge tag 'x86-microcode-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode updates from Thomas Gleixner:
- Disable late microcode loading by default. Unless the HW people get
their act together and provide a required minimum version in the
microcode header for making a halfways informed decision its just
lottery and broken.
- Warn and taint the kernel when microcode is loaded late
- Remove the old unused microcode loader interface
- Remove a redundant perf callback from the microcode loader
* tag 'x86-microcode-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode: Remove unnecessary perf callback
x86/microcode: Taint and warn on late loading
x86/microcode: Default-disable late loading
x86/microcode: Rip out the OLD_INTERFACE
Linus Torvalds [Sun, 5 Jun 2022 17:53:41 +0000 (10:53 -0700)]
Merge tag 'x86-cleanups-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Thomas Gleixner:
"A set of small x86 cleanups:
- Remove unused headers in the IDT code
- Kconfig indendation and comment fixes
- Fix all 'the the' typos in one go instead of waiting for bots to
fix one at a time"
* tag 'x86-cleanups-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Fix all occurences of the "the the" typo
x86/idt: Remove unused headers
x86/Kconfig: Fix indentation of arch/x86/Kconfig.debug
x86/Kconfig: Fix indentation and add endif comments to arch/x86/Kconfig
Linus Torvalds [Sun, 5 Jun 2022 17:47:06 +0000 (10:47 -0700)]
Merge tag 'timers-core-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull clockevent/clocksource updates from Thomas Gleixner:
- Device tree bindings for MT8186
- Tell the kernel that the RISC-V SBI timer stops in deeper power
states
- Make device tree parsing in sp804 more robust
- Dead code removal and tiny fixes here and there
- Add the missing SPDX identifiers
* tag 'timers-core-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/oxnas-rps: Fix irq_of_parse_and_map() return value
clocksource/drivers/timer-ti-dm: Remove unnecessary NULL check
clocksource/drivers/timer-sun5i: Convert to SPDX identifier
clocksource/drivers/timer-sun4i: Convert to SPDX identifier
clocksource/drivers/pistachio: Convert to SPDX identifier
clocksource/drivers/orion: Convert to SPDX identifier
clocksource/drivers/lpc32xx: Convert to SPDX identifier
clocksource/drivers/digicolor: Convert to SPDX identifier
clocksource/drivers/armada-370-xp: Convert to SPDX identifier
clocksource/drivers/mips-gic-timer: Convert to SPDX identifier
clocksource/drivers/jcore: Convert to SPDX identifier
clocksource/drivers/bcm_kona: Convert to SPDX identifier
clocksource/drivers/sp804: Avoid error on multiple instances
clocksource/drivers/riscv: Events are stopped during CPU suspend
clocksource/drivers/ixp4xx: Drop boardfile probe path
dt-bindings: timer: Add compatible for Mediatek MT8186
Linus Torvalds [Sun, 5 Jun 2022 17:40:31 +0000 (10:40 -0700)]
Merge tag 'perf-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
- Make the ICL event constraints match reality
- Remove a unused local variable
* tag 'perf-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Remove unused local variable
perf/x86/intel: Fix event constraints for ICL
Linus Torvalds [Sun, 5 Jun 2022 16:45:27 +0000 (09:45 -0700)]
Merge tag 'objtool-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixes from Thomas Gleixner:
- Handle __ubsan_handle_builtin_unreachable() correctly and treat it as
noreturn
- Allow architectures to select uaccess validation
- Use the non-instrumented bit test for test_cpu_has() to prevent
escape from non-instrumentable regions
- Use arch_ prefixed atomics for JUMP_LABEL=n builds to prevent escape
from non-instrumentable regions
- Mark a few tiny inline as __always_inline to prevent GCC from
bringing them out of line and instrumenting them
- Mark the empty stub context_tracking_enabled() as always inline as
GCC brings them out of line and instruments the empty shell
- Annotate ex_handler_msr_mce() as dead end
* tag 'objtool-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/extable: Annotate ex_handler_msr_mce() as a dead end
context_tracking: Always inline empty stubs
x86: Always inline on_thread_stack() and current_top_of_stack()
jump_label,noinstr: Avoid instrumentation for JUMP_LABEL=n builds
x86/cpu: Elide KCSAN for cpu_has() and friends
objtool: Mark __ubsan_handle_builtin_unreachable() as noreturn
objtool: Add CONFIG_HAVE_UACCESS_VALIDATION
Linus Torvalds [Sun, 5 Jun 2022 16:12:28 +0000 (09:12 -0700)]
Merge tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux
Pull hardware timestamping subsystem from Thierry Reding:
"This contains the new HTE (hardware timestamping engine) subsystem
that has been in the works for a couple of months now.
The infrastructure provided allows for drivers to register as hardware
timestamp providers, while consumers will be able to request events
that they are interested in (such as GPIOs and IRQs) to be timestamped
by the hardware providers.
Note that this currently supports only one provider, but there seems
to be enough interest in this functionality and we expect to see more
drivers added once this is merged"
[ Linus Walleij mentions the Intel PMC in the Elkhart and Tiger Lake
platforms as another future timestamp provider ]
* tag 'hte/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
dt-bindings: timestamp: Correct id path
dt-bindings: Renamed hte directory to timestamp
hte: Uninitialized variable in hte_ts_get()
hte: Fix off by one in hte_push_ts_ns()
hte: Fix possible use-after-free in tegra_hte_test_remove()
hte: Remove unused including <linux/version.h>
MAINTAINERS: Add HTE Subsystem
hte: Add Tegra HTE test driver
tools: gpio: Add new hardware clock type
gpiolib: cdev: Add hardware timestamp clock type
gpio: tegra186: Add HTE support
gpiolib: Add HTE support
dt-bindings: Add HTE bindings
hte: Add Tegra194 HTE kernel provider
drivers: Add hardware timestamp engine (HTE) subsystem
Documentation: Add HTE subsystem guide
Linus Torvalds [Sun, 5 Jun 2022 16:06:03 +0000 (09:06 -0700)]
Merge tag 'kbuild-v5.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull more Kbuild updates from Masahiro Yamada:
- Fix build regressions for parisc, csky, nios2, openrisc
- Simplify module builds for CONFIG_LTO_CLANG and CONFIG_X86_KERNEL_IBT
- Remove arch/parisc/nm, which was presumably a workaround for old
tools
- Check the odd combination of EXPORT_SYMBOL and 'static' precisely
- Make external module builds robust against "too long argument error"
- Support j, k keys for moving the cursor in nconfig
* tag 'kbuild-v5.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
kbuild: Allow to select bash in a modified environment
scripts: kconfig: nconf: make nconfig accept jk keybindings
modpost: use fnmatch() to simplify match()
modpost: simplify mod->name allocation
kbuild: factor out the common objtool arguments
kbuild: move vmlinux.o link to scripts/Makefile.vmlinux_o
kbuild: clean .tmp_* pattern by make clean
kbuild: remove redundant cleanups in scripts/link-vmlinux.sh
kbuild: rebuild multi-object modules when objtool is updated
kbuild: add cmd_and_savecmd macro
kbuild: make *.mod rule robust against too long argument error
kbuild: make built-in.a rule robust against too long argument error
kbuild: check static EXPORT_SYMBOL* by script instead of modpost
parisc: remove arch/parisc/nm
kbuild: do not create *.prelink.o for Clang LTO or IBT
kbuild: replace $(linked-object) with CONFIG options
kbuild: do not try to parse *.cmd files for objects provided by compiler
kbuild: replace $(if A,A,B) with $(or A,B) in scripts/Makefile.modpost
modpost: squash if...else-if in find_elf_symbol2()
modpost: reuse ARRAY_SIZE() macro for section_mismatch()
...
Linus Torvalds [Sun, 5 Jun 2022 02:07:15 +0000 (19:07 -0700)]
Merge tag 'pull-18-rc1-work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pathname updates from Al Viro:
"Several cleanups in fs/namei.c"
* tag 'pull-18-rc1-work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
namei: cleanup double word in comment
get rid of dead code in legitimize_root()
fs/namei.c:reserve_stack(): tidy up the call of try_to_unlazy()
Linus Torvalds [Sun, 5 Jun 2022 02:00:05 +0000 (19:00 -0700)]
Merge tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull mount handling updates from Al Viro:
"Cleanups (and one fix) around struct mount handling.
The fix is usermode_driver.c one - once you've done kern_mount(), you
must kern_unmount(); simple mntput() will end up with a leak. Several
failure exits in there messed up that way... In practice you won't hit
those particular failure exits without fault injection, though"
* tag 'pull-18-rc1-work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
move mount-related externs from fs.h to mount.h
blob_to_mnt(): kern_unmount() is needed to undo kern_mount()
m->mnt_root->d_inode->i_sb is a weird way to spell m->mnt_sb...
linux/mount.h: trim includes
uninline may_mount() and don't opencode it in fspick(2)/fsopen(2)
Linus Torvalds [Sun, 5 Jun 2022 01:52:00 +0000 (18:52 -0700)]
Merge tag 'pull-18-rc1-work.fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull file descriptor updates from Al Viro.
- Descriptor handling cleanups
* tag 'pull-18-rc1-work.fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
Unify the primitives for file descriptor closing
fs: remove fget_many and fput_many interface
io_uring_enter(): don't leave f.flags uninitialized
Linus Torvalds [Sun, 5 Jun 2022 00:42:33 +0000 (17:42 -0700)]
Merge tag '5.19-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs client fixes from Steve French:
"Nine cifs/smb3 client fixes.
Includes DFS fixes, some cleanup of leagcy SMB1 code, duplicated
message cleanup and a double free and deadlock fix"
* tag '5.19-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
cifs: fix uninitialized pointer in error case in dfs_cache_get_tgt_share
cifs: skip trailing separators of prefix paths
cifs: update internal module number
cifs: version operations for smb20 unneeded when legacy support disabled
cifs: do not build smb1ops if legacy support is disabled
cifs: fix potential deadlock in direct reclaim
cifs: when extending a file with falloc we should make files not-sparse
cifs: remove repeated debug message on cifs_put_smb_ses()
cifs: fix potential double free during failed mount
Masahiro Yamada [Mon, 30 May 2022 09:01:38 +0000 (18:01 +0900)]
modpost: simplify mod->name allocation
mod->name is set to the ELF filename with the suffix ".o" stripped.
The current code calls strdup() and free() to manipulate the string,
but a simpler approach is to pass new_module() with the name length
subtracted by 2.
Also, check if the passed filename ends with ".o" before stripping it.
The current code blindly chops the suffix:
tmp[strlen(tmp) - 2] = '\0'
It will cause buffer under-run if strlen(tmp) < 2;
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Masahiro Yamada [Sat, 28 May 2022 15:47:04 +0000 (00:47 +0900)]
kbuild: factor out the common objtool arguments
scripts/Makefile.build and scripts/link-vmlinux.sh have similar setups
for the objtool arguments.
It was difficult to factor out them because all the vmlinux build rules
were written in a shell script. It is somewhat tedious to touch the two
files every time a new objtool option is supported.
To reduce the code duplication, move the objtool for vmlinux.o into
scripts/Makefile.vmlinux_o. Then, move the common macros to Makefile.lib
so they are shared between Makefile.build and Makefile.vmlinux_o.
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