tools/testing/selftests/kvm/x86/hyperv_extended_hypercalls.c
Source file repositories/reference/linux-study-clean/tools/testing/selftests/kvm/x86/hyperv_extended_hypercalls.c
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/kvm/x86/hyperv_extended_hypercalls.c- Extension
.c- Size
- 2434 bytes
- Lines
- 99
- 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.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
kvm_util.hprocessor.hhyperv.h
Detected Declarations
function guest_codefunction main
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0-only
/*
* Test Hyper-V extended hypercall, HV_EXT_CALL_QUERY_CAPABILITIES (0x8001),
* exit to userspace and receive result in guest.
*
* Negative tests are present in hyperv_features.c
*
* Copyright 2022 Google LLC
* Author: Vipin Sharma <vipinsh@google.com>
*/
#include "kvm_util.h"
#include "processor.h"
#include "hyperv.h"
/* Any value is fine */
#define EXT_CAPABILITIES 0xbull
static void guest_code(gpa_t in_pg_gpa, gpa_t out_pg_gpa,
gva_t out_pg_gva)
{
u64 *output_gva;
wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
wrmsr(HV_X64_MSR_HYPERCALL, in_pg_gpa);
output_gva = (u64 *)out_pg_gva;
hyperv_hypercall(HV_EXT_CALL_QUERY_CAPABILITIES, in_pg_gpa, out_pg_gpa);
/* TLFS states output will be a u64 value */
GUEST_ASSERT_EQ(*output_gva, EXT_CAPABILITIES);
GUEST_DONE();
}
int main(void)
{
gva_t hcall_out_page;
gva_t hcall_in_page;
struct kvm_vcpu *vcpu;
struct kvm_run *run;
struct kvm_vm *vm;
u64 *outval;
struct ucall uc;
TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
/* Verify if extended hypercalls are supported */
if (!kvm_cpuid_has(kvm_get_supported_hv_cpuid(),
HV_ENABLE_EXTENDED_HYPERCALLS)) {
print_skip("Extended calls not supported by the kernel");
exit(KSFT_SKIP);
}
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
run = vcpu->run;
vcpu_set_hv_cpuid(vcpu);
/* Hypercall input */
hcall_in_page = vm_alloc_pages(vm, 1);
memset(addr_gva2hva(vm, hcall_in_page), 0x0, vm->page_size);
/* Hypercall output */
hcall_out_page = vm_alloc_pages(vm, 1);
memset(addr_gva2hva(vm, hcall_out_page), 0x0, vm->page_size);
vcpu_args_set(vcpu, 3, addr_gva2gpa(vm, hcall_in_page),
addr_gva2gpa(vm, hcall_out_page), hcall_out_page);
vcpu_run(vcpu);
TEST_ASSERT(run->exit_reason == KVM_EXIT_HYPERV,
"Unexpected exit reason: %u (%s)",
run->exit_reason, exit_reason_str(run->exit_reason));
outval = addr_gpa2hva(vm, run->hyperv.u.hcall.params[1]);
*outval = EXT_CAPABILITIES;
run->hyperv.u.hcall.result = HV_STATUS_SUCCESS;
vcpu_run(vcpu);
TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
"Unexpected exit reason: %u (%s)",
run->exit_reason, exit_reason_str(run->exit_reason));
switch (get_ucall(vcpu, &uc)) {
case UCALL_ABORT:
REPORT_GUEST_ASSERT(uc);
break;
case UCALL_DONE:
Annotation
- Immediate include surface: `kvm_util.h`, `processor.h`, `hyperv.h`.
- Detected declarations: `function guest_code`, `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.