tools/testing/selftests/kvm/x86/aperfmperf_test.c

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/kvm/x86/aperfmperf_test.c

Extension

.c

Size

5378 bytes

Lines

214

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• fcntl.h
• limits.h
• stdbool.h
• stdio.h
• stdint.h
• unistd.h
• asm/msr-index.h
• kvm_util.h
• processor.h
• svm_util.h
• test_util.h
• vmx.h

Detected Declarations

• function Copyright
• function read_dev_msr
• function guest_read_aperf_mperf
• function l2_guest_code
• function l1_svm_code
• function l1_vmx_code
• function guest_code
• function guest_no_aperfmperf
• function main

Annotated Snippet

switch (get_ucall(vcpu, &uc)) {
		case UCALL_DONE:
			goto done;
		case UCALL_ABORT:
			REPORT_GUEST_ASSERT(uc);
		case UCALL_SYNC:
			guest_aperf = uc.args[0];
			guest_mperf = uc.args[1];

			host_aperf_after = read_dev_msr(msr_fd, MSR_IA32_APERF);
			host_mperf_after = read_dev_msr(msr_fd, MSR_IA32_MPERF);

			TEST_ASSERT(host_aperf_before < guest_aperf,
				    "APERF: host_before (0x%" PRIx64 ") >= guest (0x%" PRIx64 ")",
				    host_aperf_before, guest_aperf);
			TEST_ASSERT(guest_aperf < host_aperf_after,
				    "APERF: guest (0x%" PRIx64 ") >= host_after (0x%" PRIx64 ")",
				    guest_aperf, host_aperf_after);
			TEST_ASSERT(host_mperf_before < guest_mperf,
				    "MPERF: host_before (0x%" PRIx64 ") >= guest (0x%" PRIx64 ")",
				    host_mperf_before, guest_mperf);
			TEST_ASSERT(guest_mperf < host_mperf_after,
				    "MPERF: guest (0x%" PRIx64 ") >= host_after (0x%" PRIx64 ")",
				    guest_mperf, host_mperf_after);

			host_aperf_before = host_aperf_after;
			host_mperf_before = host_mperf_after;

			break;
		}
	}
	TEST_FAIL("Didn't receive UCALL_DONE\n");
done:
	kvm_vm_free(vm);
	close(msr_fd);

	return 0;
}

Annotation

• Immediate include surface: `fcntl.h`, `limits.h`, `stdbool.h`, `stdio.h`, `stdint.h`, `unistd.h`, `asm/msr-index.h`, `kvm_util.h`.
• Detected declarations: `function Copyright`, `function read_dev_msr`, `function guest_read_aperf_mperf`, `function l2_guest_code`, `function l1_svm_code`, `function l1_vmx_code`, `function guest_code`, `function guest_no_aperfmperf`, `function main`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.