lkml.org 
[lkml]   [2022]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] selftests: kvm/x86: test if it checks all the bits in the LBR_FMT bit-field
Date
From: Like Xu <likexu@tencent.com>

User space only enable guest LBR feature when the exactly supported
LBR format value is initialized to the MSR_IA32_PERF_CAPABILITIES.
The input is also invalid if only partially supported bits are set.

Note for PEBS feature, the PEBS_FORMAT bit field is the primary concern,
thus if the PEBS_FORMAT input is empty, the other bits check about PEBS
(like PEBS_TRAP or ARCH_REG) will be ignored.

Signed-off-by: Like Xu <likexu@tencent.com>
---
tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
index 6ec901dab61e..98483947f921 100644
--- a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
+++ b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c
@@ -13,6 +13,7 @@

#define _GNU_SOURCE /* for program_invocation_short_name */
#include <sys/ioctl.h>
+#include <linux/bitmap.h>

#include "kvm_util.h"
#include "vmx.h"
@@ -56,7 +57,7 @@ int main(int argc, char *argv[])
const struct kvm_cpuid_entry2 *entry_a_0;
struct kvm_vm *vm;
struct kvm_vcpu *vcpu;
- int ret;
+ int ret, bit;
union cpuid10_eax eax;
union perf_capabilities host_cap;

@@ -97,6 +98,12 @@ int main(int argc, char *argv[])
ret = _vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0x30);
TEST_ASSERT(ret == 0, "Bad PERF_CAPABILITIES didn't fail.");

+ /* testcase 4, reject LBR_FMT if only partially supported bits are set */
+ for_each_set_bit(bit, (unsigned long *)&host_cap.capabilities, 6) {
+ ret = _vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, BIT_ULL(bit));
+ TEST_ASSERT(ret == 0, "Bad PERF_CAPABILITIES didn't fail.");
+ }
+
printf("Completed perf capability tests.\n");
kvm_vm_free(vm);
}
--
2.37.1
\
 
 \ /
  Last update: 2022-08-04 09:39    [W:0.834 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site