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// SPDX-License-Identifier: GPL-2.0
/*
* Test for VMX-pmu perf capability msr
*
* Copyright (C) 2021 Intel Corporation
*
* Test to check the effect of various CPUID settings on
* MSR_IA32_PERF_CAPABILITIES MSR, and check that what
* we write with KVM_SET_MSR is _not_ modified by the guest
* and check it can be retrieved with KVM_GET_MSR, also test
* the invalid LBR formats are rejected.
*/
#define _GNU_SOURCE /* for program_invocation_short_name */
#include <sys/ioctl.h>
#include "kvm_util.h"
#include "vmx.h"
#define PMU_CAP_FW_WRITES (1ULL << 13)
#define PMU_CAP_LBR_FMT 0x3f
union cpuid10_eax {
struct {
unsigned int version_id:8;
unsigned int num_counters:8;
unsigned int bit_width:8;
unsigned int mask_length:8;
} split;
unsigned int full;
};
union perf_capabilities {
struct {
u64 lbr_format:6;
u64 pebs_trap:1;
u64 pebs_arch_reg:1;
u64 pebs_format:4;
u64 smm_freeze:1;
u64 full_width_write:1;
u64 pebs_baseline:1;
u64 perf_metrics:1;
u64 pebs_output_pt_available:1;
u64 anythread_deprecated:1;
};
u64 capabilities;
};
static void guest_code(void)
{
wrmsr(MSR_IA32_PERF_CAPABILITIES, PMU_CAP_LBR_FMT);
}
int main(int argc, char *argv[])
{
const struct kvm_cpuid_entry2 *entry_a_0;
struct kvm_vm *vm;
struct kvm_vcpu *vcpu;
int ret;
union cpuid10_eax eax;
union perf_capabilities host_cap;
uint64_t val;
host_cap.capabilities = kvm_get_feature_msr(MSR_IA32_PERF_CAPABILITIES);
host_cap.capabilities &= (PMU_CAP_FW_WRITES | PMU_CAP_LBR_FMT);
/* Create VM */
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_PDCM));
TEST_REQUIRE(kvm_get_cpuid_max_basic() >= 0xa);
entry_a_0 = kvm_get_supported_cpuid_entry(0xa);
eax.full = entry_a_0->eax;
__TEST_REQUIRE(eax.split.version_id, "PMU is not supported by the vCPU");
/* testcase 1, set capabilities when we have PDCM bit */
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, PMU_CAP_FW_WRITES);
/* check capabilities can be retrieved with KVM_GET_MSR */
ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), PMU_CAP_FW_WRITES);
/* check whatever we write with KVM_SET_MSR is _not_ modified */
vcpu_run(vcpu);
ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), PMU_CAP_FW_WRITES);
/* testcase 2, check valid LBR formats are accepted */
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0);
ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), 0);
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.lbr_format);
ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), (u64)host_cap.lbr_format);
/*
* Testcase 3, check that an "invalid" LBR format is rejected. Only an
* exact match of the host's format (and 0/disabled) is allowed.
*/
for (val = 1; val <= PMU_CAP_LBR_FMT; val++) {
if (val == (host_cap.capabilities & PMU_CAP_LBR_FMT))
continue;
ret = _vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, val);
TEST_ASSERT(!ret, "Bad LBR FMT = 0x%lx didn't fail", val);
}
printf("Completed perf capability tests.\n");
kvm_vm_free(vm);
}
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