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KVM: selftests: Test all fungible features in PERF_CAPABILITIES

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Verify that userspace can set all fungible features in PERF_CAPABILITIES.
Drop the now unused #define of the "full-width writes" flag.

Link: https://lore.kernel.org/r/20230311004618.920745-15-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2023-03-10 16:46:11 -08:00
parent 69713940d2
commit 37f4e79c43
1 changed files with 24 additions and 5 deletions
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29
tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
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@@ -14,10 +14,11 @@
#define _GNU_SOURCE /* for program_invocation_short_name */
#include <sys/ioctl.h>
#include <linux/bitmap.h>
#include "kvm_util.h"
#include "vmx.h"
#define PMU_CAP_FW_WRITES (1ULL << 13)
#define PMU_CAP_LBR_FMT 0x3f
union perf_capabilities {
@@ -36,6 +37,18 @@ union perf_capabilities {
u64 capabilities;
};
/*
* The LBR format and most PEBS features are immutable, all other features are
* fungible (if supported by the host and KVM).
*/
static const union perf_capabilities immutable_caps = {
.lbr_format = -1,
.pebs_trap = 1,
.pebs_arch_reg = 1,
.pebs_format = -1,
.pebs_baseline = 1,
};
static void guest_code(void)
{
wrmsr(MSR_IA32_PERF_CAPABILITIES, PMU_CAP_LBR_FMT);
@@ -58,15 +71,22 @@ static void test_basic_perf_capabilities(union perf_capabilities host_cap)
static void test_fungible_perf_capabilities(union perf_capabilities host_cap)
{
const uint64_t fungible_caps = host_cap.capabilities & ~immutable_caps.capabilities;
struct kvm_vcpu *vcpu;
struct kvm_vm *vm = vm_create_with_one_vcpu(&vcpu, guest_code);
int bit;
/* testcase 1, set capabilities when we have PDCM bit */
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, PMU_CAP_FW_WRITES);
for_each_set_bit(bit, &fungible_caps, 64) {
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, BIT_ULL(bit));
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES,
host_cap.capabilities & ~BIT_ULL(bit));
}
vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities);
/* 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);
ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), host_cap.capabilities);
kvm_vm_free(vm);
}
@@ -102,7 +122,6 @@ int main(int argc, char *argv[])
TEST_REQUIRE(kvm_cpu_property(X86_PROPERTY_PMU_VERSION) > 0);
host_cap.capabilities = kvm_get_feature_msr(MSR_IA32_PERF_CAPABILITIES);
host_cap.capabilities &= (PMU_CAP_FW_WRITES | PMU_CAP_LBR_FMT);
TEST_ASSERT(host_cap.full_width_write,
"Full-width writes should always be supported");