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author | Paolo Bonzini <pbonzini@redhat.com> | 2023-06-03 15:16:58 -0400 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-06-03 15:16:58 -0400 |
commit | f211b45057d8b0264b494f1acebf2e8d7f9432c9 (patch) | |
tree | cb71ab9178b6f63b0aefda8d4985618bb8ddf928 /tools/testing | |
parent | Merge tag 'kvmarm-fixes-6.4-3' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff) | |
parent | KVM: selftests: Add test for race in kvm_recalculate_apic_map() (diff) | |
download | linux-f211b45057d8b0264b494f1acebf2e8d7f9432c9.tar.gz linux-f211b45057d8b0264b494f1acebf2e8d7f9432c9.tar.bz2 linux-f211b45057d8b0264b494f1acebf2e8d7f9432c9.zip |
Merge tag 'kvm-x86-fixes-6.4' of https://github.com/kvm-x86/linux into HEAD
KVM x86 fixes for 6.4
- Fix a memslot lookup bug in the NX recovery thread that could
theoretically let userspace bypass the NX hugepage mitigation
- Fix a s/BLOCKING/PENDING bug in SVM's vNMI support
- Account exit stats for fastpath VM-Exits that never leave the super
tight run-loop
- Fix an out-of-bounds bug in the optimized APIC map code, and add a
regression test for the race.
Diffstat (limited to 'tools/testing')
-rw-r--r-- | tools/testing/selftests/kvm/Makefile | 1 | ||||
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/recalc_apic_map_test.c | 74 |
2 files changed, 75 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 7a5ff646e7e7..4761b768b773 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -116,6 +116,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/sev_migrate_tests TEST_GEN_PROGS_x86_64 += x86_64/amx_test TEST_GEN_PROGS_x86_64 += x86_64/max_vcpuid_cap_test TEST_GEN_PROGS_x86_64 += x86_64/triple_fault_event_test +TEST_GEN_PROGS_x86_64 += x86_64/recalc_apic_map_test TEST_GEN_PROGS_x86_64 += access_tracking_perf_test TEST_GEN_PROGS_x86_64 += demand_paging_test TEST_GEN_PROGS_x86_64 += dirty_log_test diff --git a/tools/testing/selftests/kvm/x86_64/recalc_apic_map_test.c b/tools/testing/selftests/kvm/x86_64/recalc_apic_map_test.c new file mode 100644 index 000000000000..4c416ebe7d66 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/recalc_apic_map_test.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Test edge cases and race conditions in kvm_recalculate_apic_map(). + */ + +#include <sys/ioctl.h> +#include <pthread.h> +#include <time.h> + +#include "processor.h" +#include "test_util.h" +#include "kvm_util.h" +#include "apic.h" + +#define TIMEOUT 5 /* seconds */ + +#define LAPIC_DISABLED 0 +#define LAPIC_X2APIC (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE) +#define MAX_XAPIC_ID 0xff + +static void *race(void *arg) +{ + struct kvm_lapic_state lapic = {}; + struct kvm_vcpu *vcpu = arg; + + while (1) { + /* Trigger kvm_recalculate_apic_map(). */ + vcpu_ioctl(vcpu, KVM_SET_LAPIC, &lapic); + pthread_testcancel(); + } + + return NULL; +} + +int main(void) +{ + struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; + struct kvm_vcpu *vcpuN; + struct kvm_vm *vm; + pthread_t thread; + time_t t; + int i; + + kvm_static_assert(KVM_MAX_VCPUS > MAX_XAPIC_ID); + + /* + * Create the max number of vCPUs supported by selftests so that KVM + * has decent amount of work to do when recalculating the map, i.e. to + * make the problematic window large enough to hit. + */ + vm = vm_create_with_vcpus(KVM_MAX_VCPUS, NULL, vcpus); + + /* + * Enable x2APIC on all vCPUs so that KVM doesn't bail from the recalc + * due to vCPUs having aliased xAPIC IDs (truncated to 8 bits). + */ + for (i = 0; i < KVM_MAX_VCPUS; i++) + vcpu_set_msr(vcpus[i], MSR_IA32_APICBASE, LAPIC_X2APIC); + + ASSERT_EQ(pthread_create(&thread, NULL, race, vcpus[0]), 0); + + vcpuN = vcpus[KVM_MAX_VCPUS - 1]; + for (t = time(NULL) + TIMEOUT; time(NULL) < t;) { + vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_X2APIC); + vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_DISABLED); + } + + ASSERT_EQ(pthread_cancel(thread), 0); + ASSERT_EQ(pthread_join(thread, NULL), 0); + + kvm_vm_free(vm); + + return 0; +} |