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Run each testcase in a separate VMs to cover more possibilities;
move WRMSR close to MONITOR/MWAIT to test updating CPUID bits
while in the VM.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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KVM selftests changes for 6.15, part 2
- Fix a variety of flaws, bugs, and false failures/passes dirty_log_test, and
improve its coverage by collecting all dirty entries on each iteration.
- Fix a few minor bugs related to handling of stats FDs.
- Add infrastructure to make vCPU and VM stats FDs available to tests by
default (open the FDs during VM/vCPU creation).
- Relax an assertion on the number of HLT exits in the xAPIC IPI test when
running on a CPU that supports AMD's Idle HLT (which elides interception of
HLT if a virtual IRQ is pending and unmasked).
- Misc cleanups and fixes.
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into HEAD
KVM selftests changes for 6.15, part 1
- Misc cleanups and prep work.
- Annotate _no_printf() with "printf" so that pr_debug() statements are
checked by the compiler for default builds (and pr_info() when QUIET).
- Attempt to whack the last LLC references/misses mole in the Intel PMU
counters test by adding a data load and doing CLFLUSH{OPT} on the data
instead of the code being executed. The theory is that modern Intel CPUs
have learned new code prefetching tricks that bypass the PMU counters.
- Fix a flaw in the Intel PMU counters test where it asserts that an event is
counting correctly without actually knowing what the event counts on the
underlying hardware.
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KVM x86 misc changes for 6.15:
- Fix a bug in PIC emulation that caused KVM to emit a spurious KVM_REQ_EVENT.
- Add a helper to consolidate handling of mp_state transitions, and use it to
clear pv_unhalted whenever a vCPU is made RUNNABLE.
- Defer runtime CPUID updates until KVM emulates a CPUID instruction, to
coalesce updates when multiple pieces of vCPU state are changing, e.g. as
part of a nested transition.
- Fix a variety of nested emulation bugs, and add VMX support for synthesizing
nested VM-Exit on interception (instead of injecting #UD into L2).
- Drop "support" for PV Async #PF with proctected guests without SEND_ALWAYS,
as KVM can't get the current CPL.
- Misc cleanups
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Print out the index of mismatching XSAVE bytes using unsigned decimal
format. Some versions of clang complain about trying to print an integer
as an unsigned char.
x86/sev_smoke_test.c:55:51: error: format specifies type 'unsigned char'
but the argument has type 'int' [-Werror,-Wformat]
Fixes: 8c53183dbaa2 ("selftests: kvm: add test for transferring FPU state into VMSA")
Link: https://lore.kernel.org/r/20250228233852.3855676-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If the CPU supports Idle HLT, which elides HLT VM-Exits if the vCPU has an
unmasked pending IRQ or NMI, relax the xAPIC IPI test's assertion on the
number of HLT exits to only require that the number of exits is less than
or equal to the number of HLT instructions that were executed. I.e. don't
fail the test if Idle HLT does what it's supposed to do.
Note, unfortunately there's no way to determine if *KVM* supports Idle HLT,
as this_cpu_has() checks raw CPU support, and kvm_cpu_has() checks what can
be exposed to L1, i.e. the latter would check if KVM supports nested Idle
HLT. But, since the assert is purely bonus coverage, checking for CPU
support is good enough.
Cc: Manali Shukla <Manali.Shukla@amd.com>
Tested-by: Manali Shukla <Manali.Shukla@amd.com>
Link: https://lore.kernel.org/r/20250226231809.3183093-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add an L1 (guest) assert to the nested exceptions test to verify that KVM
doesn't put VMRUN in an STI shadow (AMD CPUs bleed the shadow into the
guest's int_state if a #VMEXIT occurs before VMRUN fully completes).
Add a similar assert to the VMX side as well, because why not.
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20250224165442.2338294-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add a rudimentary test for validating KVM's handling of L1 hypervisor
intercepts during instruction emulation on behalf of L2. To minimize
complexity and avoid overlap with other tests, only validate KVM's
handling of instructions that L1 wants to intercept, i.e. that generate a
nested VM-Exit. Full testing of emulation on behalf of L2 is better
achieved by running existing (forced) emulation tests in a VM, (although
on VMX, getting L0 to emulate on #UD requires modifying either L1 KVM to
not intercept #UD, or modifying L0 KVM to prioritize L0's exception
intercepts over L1's intercepts, as is done by KVM for SVM).
Since emulation should never be successful, i.e. L2 always exits to L1,
dynamically generate the L2 code stream instead of adding a helper for
each instruction. Doing so requires hand coding instruction opcodes, but
makes it significantly easier for the test to compute the expected "next
RIP" and instruction length.
Link: https://lore.kernel.org/r/20250201015518.689704-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Now that the binary stats cache infrastructure is largely scope agnostic,
add support for vCPU-scoped stats. Like VM stats, open and cache the
stats FD when the vCPU is created so that it's guaranteed to be valid when
vcpu_get_stats() is invoked.
Account for the extra per-vCPU file descriptor in kvm_set_files_rlimit(),
so that tests that create large VMs don't run afoul of resource limits.
To sanity check that the infrastructure actually works, and to get a bit
of bonus coverage, add an assert in x86's xapic_ipi_test to verify that
the number of HLTs executed by the test matches the number of HLT exits
observed by KVM.
Tested-by: Manali Shukla <Manali.Shukla@amd.com>
Link: https://lore.kernel.org/r/20250111005049.1247555-9-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Turn vm_get_stat() into a macro that generates a string for the stat name,
as opposed to taking a string. This will allow hardening stat usage in
the future to generate errors on unknown stats at compile time.
No functional change intended.
Link: https://lore.kernel.org/r/20250111005049.1247555-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Add testcases to x86's Hyper-V CPUID test to verify that KVM advertises
support for features that require an in-kernel local APIC appropriately,
i.e. that KVM hides support from the vCPU-scoped ioctl if the VM doesn't
have an in-kernel local APIC.
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250118003454.2619573-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Allocate, get, and free the CPUID array in the Hyper-V CPUID test in the
test's core helper, instead of copy+pasting code at each call site. In
addition to deduplicating a small amount of code, restricting visibility
of the array to a single invocation of the core test prevents "leaking" an
array across test cases. Passing in @vcpu to the helper will also allow
pivoting on VM-scoped information without needing to pass more booleans,
e.g. to conditionally assert on features that require an in-kernel APIC.
To avoid use-after-free bugs due to overzealous and careless developers,
opportunstically add a comment to explain that the system-scoped helper
caches the Hyper-V CPUID entries, i.e. that the caller is not responsible
for freeing the memory.
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250118003454.2619573-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Make the Hyper-V CPUID test's local helper test_hv_cpuid_e2big() static,
it's not used outside of the test (and isn't intended to be).
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250118003454.2619573-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Print out the expected vs. actual count of the Top-Down Slots event on
failure in the Intel PMU counters test. GUEST_ASSERT() only expands
constants/macros, i.e. only prints the value of the expected count, which
makes it difficult to debug and triage failures.
Link: https://lore.kernel.org/r/20250117234204.2600624-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Now that validation of event count is tied to hardware support for event,
and not to guest support for an event, drop the unused "event" parameter
from the various helpers.
No functional change intended.
Link: https://lore.kernel.org/r/20250117234204.2600624-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Drop the local "nr_arch_events" in the Intel PMU counters test as the test
asserts that "nr_arch_events <= NR_INTEL_ARCH_EVENTS", and then sets
nr_arch_events to the max of the two. I.e. nr_arch_events is guaranteed
to be NR_INTEL_ARCH_EVENTS for the meat of the test, just use
NR_INTEL_ARCH_EVENTS directly.
No functional change intended.
Link: https://lore.kernel.org/r/20250117234204.2600624-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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In the Intel PMU counters test, only validate the counts for architectural
events that are supported in hardware. If an arch event isn't supported,
the event selector may enable a completely different event, and thus the
logic for the expected count is bogus.
This fixes test failures on pre-Icelake systems due to the encoding for
the architectural Top-Down Slots event corresponding to something else
(at least on the Skylake family of CPUs).
Note, validation relies on *hardware* support, not KVM support and not
guest support. Architectural events are all about enumerating the event
selector encoding; lack of enumeration for an architectural event doesn't
mean the event itself is unsupported, i.e. the event should still count as
expected even if KVM and/or guest CPUID doesn't enumerate the event as
being "architectural".
Note #2, it's desirable to _program_ the architectural event encoding even
if hardware doesn't support the event. The count can't be validated when
the event is fully enabled, but KVM should still let the guest program the
event selector, and the PMC shouldn't count if the event is disabled.
Fixes: 4f1bd6b16074 ("KVM: selftests: Test Intel PMU architectural events on gp counters")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202501141009.30c629b4-lkp@intel.com
Debugged-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20250117234204.2600624-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Wrap PMU counter test's array of Intel architectrual in a helper function
so that the events can be queried in multiple locations. Add a comment to
explain the need for a wrapper.
No functional change intended.
Link: https://lore.kernel.org/r/20250117234204.2600624-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Copy KVM-Unit-Tests' x86 helpers for emitting STI and CLI, comments and
all, and use them throughout x86 selftests. The safe_halt() and sti_nop()
logic in particular benefits from centralized comments, as the behavior
isn't obvious unless the reader is already aware of the STI shadow.
Cc: Manali Shukla <Manali.Shukla@amd.com>
Link: https://lore.kernel.org/r/20241220012617.3513898-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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In the PMU counters test, add a data load in the measured loop and target
the data with CLFLUSH{OPT} in order to (try to) guarantee the loop
generates LLC misses and fills. Per the SDM, some hardware prefetchers
are allowed to omit relevant PMU events, and Emerald Rapids (and possibly
Sapphire Rapids) appears to have gained an instruction prefetcher that
bypasses event counts. E.g. the test will consistently fail on EMR CPUs,
but then pass with seemingly benign changes to the code.
The event count includes speculation and cache line fills due to the
first-level cache hardware prefetcher, but may exclude cache line fills
due to other hardware-prefetchers.
Generate a data load as a last ditch effort to preserve the (minimal) test
coverage for LLC references and misses.
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20241127235627.4049619-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Fix goofs in PMU counter test's assertion macros where the macros
unintentionally reference variables in the parent scope. The code "works"
as-is purely by accident, as all users define a variable with the correct
name (and usage).
Fixes: cd34fd8c758e ("KVM: selftests: Test PMC virtualization with forced emulation")
Signed-off-by: Colton Lewis <coltonlewis@google.com>
Reviewed-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20240918205319.3517569-2-coltonlewis@google.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Implement a function for setting the IDT descriptor from the guest
code. Replace the existing lidt occurrences with calls to this function
as `lidt` is used in multiple places.
Signed-off-by: Ivan Orlov <iorlov@amazon.com>
Link: https://lore.kernel.org/r/20241217181458.68690-7-iorlov@amazon.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Rework x86's KVM PV features test to align with KVM's new, fixed behavior
of not allowing userspace to disable HLT-exiting after vCPUs have been
created. Rework the core testcase to disable HLT-exiting before creating
a vCPU, and opportunistically modify keep the paired VM+vCPU creation to
verify that KVM rejects KVM_CAP_X86_DISABLE_EXITS as expected.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-18-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Actually check for KVM support for disabling HLT-exiting instead of
effectively checking that KVM_CAP_X86_DISABLE_EXITS is #defined to a
non-zero value, and convert the TEST_REQUIRE() to a simple return so
that only the sub-test is skipped if HLT-exiting is mandatory.
The goof has likely gone unnoticed because all x86 CPUs support disabling
HLT-exiting, only systems with the opt-in mitigate_smt_rsb KVM module
param disallow HLT-exiting.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-17-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Extend x86's set sregs test to verify that KVM sets/clears OSXSAVE and
OSKPKE according to CR4.XSAVE and CR4.PKE respectively. For performance
reasons, KVM is responsible for emulating the architectural behavior of
the OS CPUID bits tracking CR4.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Rework x86's set sregs test to verify that KVM enforces CPUID vs. CR4
features even if userspace hasn't explicitly set guest CPUID. KVM used to
allow userspace to set any KVM-supported CR4 value prior to KVM_SET_CPUID2,
and the test verified that behavior.
However, the testcase was written purely to verify KVM's existing behavior,
i.e. was NOT written to match the needs of real world VMMs.
Opportunistically verify that KVM continues to reject unsupported features
after KVM_SET_CPUID2 (using KVM_GET_SUPPORTED_CPUID).
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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Use the kernel's canonical $(ARCH) paths instead of the raw target triple
for KVM selftests directories. KVM selftests are quite nearly the only
place in the entire kernel that using the target triple for directories,
tools/testing/selftests/drivers/s390x being the lone holdout.
Using the kernel's preferred nomenclature eliminates the minor, but
annoying, friction of having to translate to KVM's selftests directories,
e.g. for pattern matching, opening files, running selftests, etc.
Opportunsitically delete file comments that reference the full path of the
file, as they are obviously prone to becoming stale, and serve no known
purpose.
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20241128005547.4077116-16-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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