diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c b/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c new file mode 100644 index 0000000000..80aa3d8b18 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/monitor_mwait_test.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> + +#include "kvm_util.h" +#include "processor.h" + +#define CPUID_MWAIT (1u << 3) + +enum monitor_mwait_testcases { + MWAIT_QUIRK_DISABLED = BIT(0), + MISC_ENABLES_QUIRK_DISABLED = BIT(1), + MWAIT_DISABLED = BIT(2), +}; + +/* + * If both MWAIT and its quirk are disabled, MONITOR/MWAIT should #UD, in all + * other scenarios KVM should emulate them as nops. + */ +#define GUEST_ASSERT_MONITOR_MWAIT(insn, testcase, vector) \ +do { \ + bool fault_wanted = ((testcase) & MWAIT_QUIRK_DISABLED) && \ + ((testcase) & MWAIT_DISABLED); \ + \ + if (fault_wanted) \ + __GUEST_ASSERT((vector) == UD_VECTOR, \ + "Expected #UD on " insn " for testcase '0x%x', got '0x%x'", vector); \ + else \ + __GUEST_ASSERT(!(vector), \ + "Expected success on " insn " for testcase '0x%x', got '0x%x'", vector); \ +} while (0) + +static void guest_monitor_wait(int testcase) +{ + u8 vector; + + GUEST_SYNC(testcase); + + /* + * Arbitrarily MONITOR this function, SVM performs fault checks before + * intercept checks, so the inputs for MONITOR and MWAIT must be valid. + */ + vector = kvm_asm_safe("monitor", "a"(guest_monitor_wait), "c"(0), "d"(0)); + GUEST_ASSERT_MONITOR_MWAIT("MONITOR", testcase, vector); + + vector = kvm_asm_safe("mwait", "a"(guest_monitor_wait), "c"(0), "d"(0)); + GUEST_ASSERT_MONITOR_MWAIT("MWAIT", testcase, vector); +} + +static void guest_code(void) +{ + guest_monitor_wait(MWAIT_DISABLED); + + guest_monitor_wait(MWAIT_QUIRK_DISABLED | MWAIT_DISABLED); + + guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_DISABLED); + guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED); + + guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED | MWAIT_DISABLED); + guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED); + + GUEST_DONE(); +} + +int main(int argc, char *argv[]) +{ + uint64_t disabled_quirks; + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct ucall uc; + int testcase; + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_DISABLE_QUIRKS2)); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_MWAIT); + + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + + while (1) { + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_SYNC: + testcase = uc.args[1]; + break; + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + goto done; + case UCALL_DONE: + goto done; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + goto done; + } + + disabled_quirks = 0; + if (testcase & MWAIT_QUIRK_DISABLED) + disabled_quirks |= KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS; + if (testcase & MISC_ENABLES_QUIRK_DISABLED) + disabled_quirks |= KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT; + vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, disabled_quirks); + + /* + * If the MISC_ENABLES quirk (KVM neglects to update CPUID to + * enable/disable MWAIT) is disabled, toggle the ENABLE_MWAIT + * bit in MISC_ENABLES accordingly. If the quirk is enabled, + * the only valid configuration is MWAIT disabled, as CPUID + * can't be manually changed after running the vCPU. + */ + if (!(testcase & MISC_ENABLES_QUIRK_DISABLED)) { + TEST_ASSERT(testcase & MWAIT_DISABLED, + "Can't toggle CPUID features after running vCPU"); + continue; + } + + vcpu_set_msr(vcpu, MSR_IA32_MISC_ENABLE, + (testcase & MWAIT_DISABLED) ? 0 : MSR_IA32_MISC_ENABLE_MWAIT); + } + +done: + kvm_vm_free(vm); + return 0; +} |