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2025-04-04KVM: selftests: Add option to rseq test to override /dev/cpu_dma_latencySean Christopherson
Add a "-l <latency>" param to the rseq test so that the user can override /dev/cpu_dma_latency, as described by the test's suggested workaround for not being able to complete enough migrations. cpu_dma_latency is not a normal file, even as far as procfs files go. Writes to cpu_dma_latency only persist so long as the file is open, e.g. so that the kernel automatically reverts back to a power-optimized state once the sensitive workload completes. Provide the necessary functionality instead of effectively forcing the user to write a non-obvious wrapper. Cc: Dongsheng Zhang <dongsheng.x.zhang@intel.com> Cc: Zide Chen <zide.chen@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-ID: <20250401142238.819487-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-12Merge tag 'kvm-x86-selftests_utils-6.10' of https://github.com/kvm-x86/linux ↵Paolo Bonzini
into HEAD KVM selftests treewide updates for 6.10: - Define _GNU_SOURCE for all selftests to fix a warning that was introduced by a change to kselftest_harness.h late in the 6.9 cycle, and because forcing every test to #define _GNU_SOURCE is painful. - Provide a global psuedo-RNG instance for all tests, so that library code can generate random, but determinstic numbers. - Use the global pRNG to randomly force emulation of select writes from guest code on x86, e.g. to help validate KVM's emulation of locked accesses. - Rename kvm_util_base.h back to kvm_util.h, as the weird layer of indirection was added purely to avoid manually #including ucall_common.h in a handful of locations. - Allocate and initialize x86's GDT, IDT, TSS, segments, and default exception handlers at VM creation, instead of forcing tests to manually trigger the related setup.
2024-05-02KVM: selftests: Allow skipping the KVM_RUN sanity check in rseq_testZide Chen
The rseq test's migration worker delays 1-10 us, assuming that one KVM_RUN iteration only takes a few microseconds. But if the CPU low power wakeup latency is large enough, for example, hundreds or even thousands of microseconds for deep C-state exit latencies on x86 server CPUs, it may happen that the target CPU is unable to wakeup and run the vCPU before the migration worker starts to migrate the vCPU thread to the _next_ CPU. If the system workload is light, most CPUs could be at a certain low power state, which may result in less successful migrations and fail the migration/KVM_RUN ratio sanity check. But this is not supposed to be deemed a test failure. Add a command line option to skip the sanity check, along with a comment and a verbose assert message to try to help the user resolve the potential source of failures without having to resort to disabling the check. Co-developed-by: Dongsheng Zhang <dongsheng.x.zhang@intel.com> Signed-off-by: Dongsheng Zhang <dongsheng.x.zhang@intel.com> Signed-off-by: Zide Chen <zide.chen@intel.com> Link: https://lore.kernel.org/r/20240502213936.27619-1-zide.chen@intel.com [sean: massage changelog] Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-04-29Revert "kvm: selftests: move base kvm_util.h declarations to kvm_util_base.h"Sean Christopherson
Effectively revert the movement of code from kvm_util.h => kvm_util_base.h, as the TL;DR of the justification for the move was to avoid #idefs and/or circular dependencies between what ended up being ucall_common.h and what was (and now again, is), kvm_util.h. But avoiding #ifdef and circular includes is trivial: don't do that. The cost of removing kvm_util_base.h is a few extra includes of ucall_common.h, but that cost is practically nothing. On the other hand, having a "base" version of a header that is really just the header itself is confusing, and makes it weird/hard to choose names for headers that actually are "base" headers, e.g. to hold core KVM selftests typedefs. For all intents and purposes, this reverts commit 7d9a662ed9f0403e7b94940dceb81552b8edb931. Reviewed-by: Ackerley Tng <ackerleytng@google.com> Link: https://lore.kernel.org/r/20240314232637.2538648-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-04-29KVM: selftests: Define _GNU_SOURCE for all selftests codeSean Christopherson
Define _GNU_SOURCE is the base CFLAGS instead of relying on selftests to manually #define _GNU_SOURCE, which is repetitive and error prone. E.g. kselftest_harness.h requires _GNU_SOURCE for asprintf(), but if a selftest includes kvm_test_harness.h after stdio.h, the include guards result in the effective version of stdio.h consumed by kvm_test_harness.h not defining asprintf(): In file included from x86_64/fix_hypercall_test.c:12: In file included from include/kvm_test_harness.h:11: ../kselftest_harness.h:1169:2: error: call to undeclared function 'asprintf'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 1169 | asprintf(&test_name, "%s%s%s.%s", f->name, | ^ When including the rseq selftest's "library" code, #undef _GNU_SOURCE so that rseq.c controls whether or not it wants to build with _GNU_SOURCE. Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Oliver Upton <oliver.upton@linux.dev> Acked-by: Anup Patel <anup@brainfault.org> Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Link: https://lore.kernel.org/r/20240423190308.2883084-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-01-29KVM: selftests: Remove redundant newlinesAndrew Jones
TEST_* functions append their own newline. Remove newlines from TEST_* callsites to avoid extra newlines in output. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20231206170241.82801-8-ajones@ventanamicro.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-01-30KVM: selftests: Fix build of rseq testMark Brown
The KVM rseq test is failing to build in -next due to a commit merged from the tip tree which adds a wrapper for sys_getcpu() to the rseq kselftests, conflicting with the wrapper already included in the KVM selftest: rseq_test.c:48:13: error: conflicting types for 'sys_getcpu' 48 | static void sys_getcpu(unsigned *cpu) | ^~~~~~~~~~ In file included from rseq_test.c:23: ../rseq/rseq.c:82:12: note: previous definition of 'sys_getcpu' was here 82 | static int sys_getcpu(unsigned *cpu, unsigned *node) | ^~~~~~~~~~ Fix this by removing the local wrapper and moving the result check up to the caller. Fixes: 99babd04b250 ("selftests/rseq: Implement rseq numa node id field selftest") Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/r/20230106-fix-kvm-rseq-build-v1-1-b704d9831d02@kernel.org
2022-11-16KVM: selftests: move common startup logic to kvm_util.cVishal Annapurve
Consolidate common startup logic in one place by implementing a single setup function with __attribute((constructor)) for all selftests within kvm_util.c. This allows moving logic like: /* Tell stdout not to buffer its content */ setbuf(stdout, NULL); to a single file for all selftests. This will also allow any required setup at entry in future to be done in common main function. Link: https://lore.kernel.org/lkml/Ywa9T+jKUpaHLu%2Fl@google.com Suggested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Reviewed-by: Peter Gonda <pgonda@google.com> Signed-off-by: Vishal Annapurve <vannapurve@google.com> Link: https://lore.kernel.org/r/20221115213845.3348210-2-vannapurve@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2022-11-16KVM: selftests: Automatically do init_ucall() for non-barebones VMsSean Christopherson
Do init_ucall() automatically during VM creation to kill two (three?) birds with one stone. First, initializing ucall immediately after VM creations allows forcing aarch64's MMIO ucall address to immediately follow memslot0. This is still somewhat fragile as tests could clobber the MMIO address with a new memslot, but it's safe-ish since tests have to be conversative when accounting for memslot0. And this can be hardened in the future by creating a read-only memslot for the MMIO page (KVM ARM exits with MMIO if the guest writes to a read-only memslot). Add a TODO to document that selftests can and should use a memslot for the ucall MMIO (doing so requires yet more rework because tests assumes thay can use all memslots except memslot0). Second, initializing ucall for all VMs prepares for making ucall initialization meaningful on all architectures. aarch64 is currently the only arch that needs to do any setup, but that will change in the future by switching to a pool-based implementation (instead of the current stack-based approach). Lastly, defining the ucall MMIO address from common code will simplify switching all architectures (except s390) to a common MMIO-based ucall implementation (if there's ever sufficient motivation to do so). Cc: Oliver Upton <oliver.upton@linux.dev> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Tested-by: Peter Gonda <pgonda@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20221006003409.649993-4-seanjc@google.com
2022-09-22selftests: kvm: Fix a compile error in selftests/kvm/rseq_test.cJinrong Liang
The following warning appears when executing: make -C tools/testing/selftests/kvm rseq_test.c: In function ‘main’: rseq_test.c:237:33: warning: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Wimplicit-function-declaration] (void *)(unsigned long)gettid()); ^~~~~~ getgid /usr/bin/ld: /tmp/ccr5mMko.o: in function `main': ../kvm/tools/testing/selftests/kvm/rseq_test.c:237: undefined reference to `gettid' collect2: error: ld returned 1 exit status make: *** [../lib.mk:173: ../kvm/tools/testing/selftests/kvm/rseq_test] Error 1 Use the more compatible syscall(SYS_gettid) instead of gettid() to fix it. More subsequent reuse may cause it to be wrapped in a lib file. Signed-off-by: Jinrong Liang <cloudliang@tencent.com> Message-Id: <20220802071240.84626-1-cloudliang@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-10KVM: selftests: Use getcpu() instead of sched_getcpu() in rseq_testGavin Shan
sched_getcpu() is glibc dependent and it can simply return the CPU ID from the registered rseq information, as Florian Weimer pointed. In this case, it's pointless to compare the return value from sched_getcpu() and that fetched from the registered rseq information. Fix the issue by replacing sched_getcpu() with getcpu(), as Florian suggested. The comments are modified accordingly by replacing "sched_getcpu()" with "getcpu()". Reported-by: Yihuang Yu <yihyu@redhat.com> Suggested-by: Florian Weimer <fweimer@redhat.com> Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Message-Id: <20220810104114.6838-3-gshan@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-10KVM: selftests: Make rseq compatible with glibc-2.35Gavin Shan
The rseq information is registered by TLS, starting from glibc-2.35. In this case, the test always fails due to syscall(__NR_rseq). For example, on RHEL9.1 where upstream glibc-2.35 features are enabled on downstream glibc-2.34, the test fails like below. # ./rseq_test ==== Test Assertion Failure ==== rseq_test.c:60: !r pid=112043 tid=112043 errno=22 - Invalid argument 1 0x0000000000401973: main at rseq_test.c:226 2 0x0000ffff84b6c79b: ?? ??:0 3 0x0000ffff84b6c86b: ?? ??:0 4 0x0000000000401b6f: _start at ??:? rseq failed, errno = 22 (Invalid argument) # rpm -aq | grep glibc-2 glibc-2.34-39.el9.aarch64 Fix the issue by using "../rseq/rseq.c" to fetch the rseq information, registred by TLS if it exists. Otherwise, we're going to register our own rseq information as before. Reported-by: Yihuang Yu <yihyu@redhat.com> Suggested-by: Florian Weimer <fweimer@redhat.com> Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Message-Id: <20220810104114.6838-2-gshan@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-01Merge remote-tracking branch 'kvm/next' into kvm-next-5.20Paolo Bonzini
KVM/s390, KVM/x86 and common infrastructure changes for 5.20 x86: * Permit guests to ignore single-bit ECC errors * Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache * Intel IPI virtualization * Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS * PEBS virtualization * Simplify PMU emulation by just using PERF_TYPE_RAW events * More accurate event reinjection on SVM (avoid retrying instructions) * Allow getting/setting the state of the speaker port data bit * Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent * "Notify" VM exit (detect microarchitectural hangs) for Intel * Cleanups for MCE MSR emulation s390: * add an interface to provide a hypervisor dump for secure guests * improve selftests to use TAP interface * enable interpretive execution of zPCI instructions (for PCI passthrough) * First part of deferred teardown * CPU Topology * PV attestation * Minor fixes Generic: * new selftests API using struct kvm_vcpu instead of a (vm, id) tuple x86: * Use try_cmpxchg64 instead of cmpxchg64 * Bugfixes * Ignore benign host accesses to PMU MSRs when PMU is disabled * Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior * x86/MMU: Allow NX huge pages to be disabled on a per-vm basis * Port eager page splitting to shadow MMU as well * Enable CMCI capability by default and handle injected UCNA errors * Expose pid of vcpu threads in debugfs * x2AVIC support for AMD * cleanup PIO emulation * Fixes for LLDT/LTR emulation * Don't require refcounted "struct page" to create huge SPTEs x86 cleanups: * Use separate namespaces for guest PTEs and shadow PTEs bitmasks * PIO emulation * Reorganize rmap API, mostly around rmap destruction * Do not workaround very old KVM bugs for L0 that runs with nesting enabled * new selftests API for CPUID
2022-07-19KVM: selftests: Fix target thread to be migrated in rseq_testGavin Shan
In rseq_test, there are two threads, which are vCPU thread and migration worker separately. Unfortunately, the test has the wrong PID passed to sched_setaffinity() in the migration worker. It forces migration on the migration worker because zeroed PID represents the calling thread, which is the migration worker itself. It means the vCPU thread is never enforced to migration and it can migrate at any time, which eventually leads to failure as the following logs show. host# uname -r 5.19.0-rc6-gavin+ host# # cat /proc/cpuinfo | grep processor | tail -n 1 processor : 223 host# pwd /home/gavin/sandbox/linux.main/tools/testing/selftests/kvm host# for i in `seq 1 100`; do \ echo "--------> $i"; ./rseq_test; done --------> 1 --------> 2 --------> 3 --------> 4 --------> 5 --------> 6 ==== Test Assertion Failure ==== rseq_test.c:265: rseq_cpu == cpu pid=3925 tid=3925 errno=4 - Interrupted system call 1 0x0000000000401963: main at rseq_test.c:265 (discriminator 2) 2 0x0000ffffb044affb: ?? ??:0 3 0x0000ffffb044b0c7: ?? ??:0 4 0x0000000000401a6f: _start at ??:? rseq CPU = 4, sched CPU = 27 Fix the issue by passing correct parameter, TID of the vCPU thread, to sched_setaffinity() in the migration worker. Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs") Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Message-Id: <20220719020830.3479482-1-gshan@redhat.com> Reviewed-by: Andrew Jones <andrew.jones@linux.dev> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-11KVM: selftests: Add TEST_REQUIRE macros to reduce skipping copy+pasteSean Christopherson
Add TEST_REQUIRE() and __TEST_REQUIRE() to replace the myriad open coded instances of selftests exiting with KSFT_SKIP after printing an informational message. In addition to reducing the amount of boilerplate code in selftests, the UPPERCASE macro names make it easier to visually identify a test's requirements. Convert usage that erroneously uses something other than print_skip() and/or "exits" with '0' or some other non-KSFT_SKIP value. Intentionally drop a kvm_vm_free() in aarch64/debug-exceptions.c as part of the conversion. All memory and file descriptors are freed on process exit, so the explicit free is superfluous. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-11KVM: selftests: Purge vm+vcpu_id == vcpu sillinessSean Christopherson
Take a vCPU directly instead of a VM+vcpu pair in all vCPU-scoped helpers and ioctls. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-11KVM: selftests: Convert rseq_test away from VCPU_IDSean Christopherson
Convert rseq_test to use vm_create_with_one_vcpu() and pass around a 'struct kvm_vcpu' object instead of using a global VCPU_ID. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30KVM: selftests: Ensure all migrations are performed when test is affinedSean Christopherson
Rework the CPU selection in the migration worker to ensure the specified number of migrations are performed when the test iteslf is affined to a subset of CPUs. The existing logic skips iterations if the target CPU is not in the original set of possible CPUs, which causes the test to fail if too many iterations are skipped. ==== Test Assertion Failure ==== rseq_test.c:228: i > (NR_TASK_MIGRATIONS / 2) pid=10127 tid=10127 errno=4 - Interrupted system call 1 0x00000000004018e5: main at rseq_test.c:227 2 0x00007fcc8fc66bf6: ?? ??:0 3 0x0000000000401959: _start at ??:? Only performed 4 KVM_RUNs, task stalled too much? Calculate the min/max possible CPUs as a cheap "best effort" to avoid high runtimes when the test is affined to a small percentage of CPUs. Alternatively, a list or xarray of the possible CPUs could be used, but even in a horrendously inefficient setup, such optimizations are not needed because the runtime is completely dominated by the cost of migrating the task, and the absolute runtime is well under a minute in even truly absurd setups, e.g. running on a subset of vCPUs in a VM that is heavily overcommited (16 vCPUs per pCPU). Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs") Reported-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210929234112.1862848-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-24selftests: KVM: Call ucall_init when setting up in rseq_testOliver Upton
While x86 does not require any additional setup to use the ucall infrastructure, arm64 needs to set up the MMIO address used to signal a ucall to userspace. rseq_test does not initialize the MMIO address, resulting in the test spinning indefinitely. Fix the issue by calling ucall_init() during setup. Fixes: 61e52f1630f5 ("KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs") Signed-off-by: Oliver Upton <oupton@google.com> Message-Id: <20210923220033.4172362-1-oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugsSean Christopherson
Add a test to verify an rseq's CPU ID is updated correctly if the task is migrated while the kernel is handling KVM_RUN. This is a regression test for a bug introduced by commit 72c3c0fe54a3 ("x86/kvm: Use generic xfer to guest work function"), where TIF_NOTIFY_RESUME would be cleared by KVM without updating rseq, leading to a stale CPU ID and other badness. Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Message-Id: <20210901203030.1292304-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>