[PATCH 04/31] KVM: selftests: Test address translation for Hyper-V direct L2 hypercalls
From: Paolo Bonzini
Date: Fri Sep 18 2026 - 10:02:05 EST
Test that the TLB flush hypercalls, when executed by L2, translate their
input addresses through the guest's EPT or NPT.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
tools/testing/selftests/kvm/x86/hyperv_evmcs.c | 12 +++++++++++-
tools/testing/selftests/kvm/x86/hyperv_svm_test.c | 13 ++++++++++++-
2 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
index 63ea1533e4ea..29baae74ad3a 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
+++ b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
@@ -18,6 +18,8 @@
#include "hyperv.h"
#include "vmx.h"
+#define L2_HCALL_INPUT_GPA 0x100000000ull
+
static int ud_count;
static void guest_ud_handler(struct ex_regs *regs)
@@ -60,6 +62,8 @@ void l2_guest_code(void)
rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
/* L2 TLB flush tests */
+ hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
+ L2_HCALL_INPUT_GPA, 0);
hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE | HV_HYPERCALL_FAST_BIT, 0x0,
HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES | HV_FLUSH_ALL_PROCESSORS);
rdmsr_from_l2(MSR_FS_BASE);
@@ -228,7 +232,7 @@ static struct kvm_vcpu *save_restore_vm(struct kvm_vm *vm,
int main(int argc, char *argv[])
{
gva_t vmx_pages_gva = 0, hv_pages_gva = 0;
- gva_t hcall_page;
+ gva_t hcall_input_page, hcall_page;
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
@@ -239,17 +243,23 @@ int main(int argc, char *argv[])
TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE));
TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS));
TEST_REQUIRE(kvm_hv_cpu_has(HV_X64_NESTED_DIRECT_FLUSH));
+ TEST_REQUIRE(kvm_cpu_has_ept());
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+ vm_enable_ept(vm);
hcall_page = vm_alloc_pages(vm, 1);
memset(addr_gva2hva(vm, hcall_page), 0x0, getpagesize());
+ hcall_input_page = vm_alloc_page(vm);
+ memset(addr_gva2hva(vm, hcall_input_page), 0, getpagesize());
vcpu_set_hv_cpuid(vcpu);
vcpu_enable_evmcs(vcpu);
vcpu_alloc_vmx(vm, &vmx_pages_gva);
vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);
+ tdp_identity_map_default_memslots(vm);
+ tdp_map(vm, L2_HCALL_INPUT_GPA, addr_gva2gpa(vm, hcall_input_page), PAGE_SIZE);
vcpu_args_set(vcpu, 3, vmx_pages_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));
vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);
diff --git a/tools/testing/selftests/kvm/x86/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86/hyperv_svm_test.c
index 1f74b0fa9b83..18f0ad6debd8 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86/hyperv_svm_test.c
@@ -18,6 +18,8 @@
#include "svm_util.h"
#include "hyperv.h"
+#define L2_HCALL_INPUT_GPA 0x100000000ull
+
/* Exit to L1 from L2 with RDMSR instruction */
static inline void rdmsr_from_l2(u32 msr)
{
@@ -45,6 +47,8 @@ void l2_guest_code(void)
GUEST_SYNC(5);
/* L2 TLB flush tests */
+ hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
+ L2_HCALL_INPUT_GPA, 0);
hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
HV_HYPERCALL_FAST_BIT, 0x0,
HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
@@ -146,7 +150,7 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm,
int main(int argc, char *argv[])
{
gva_t nested_gva = 0, hv_pages_gva = 0;
- gva_t hcall_page;
+ gva_t hcall_input_page, hcall_page;
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
struct ucall uc;
@@ -154,15 +158,22 @@ int main(int argc, char *argv[])
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
TEST_REQUIRE(kvm_hv_cpu_has(HV_X64_NESTED_DIRECT_FLUSH));
+ TEST_REQUIRE(kvm_cpu_has_npt());
/* Create VM */
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+ vm_enable_npt(vm);
vcpu_set_hv_cpuid(vcpu);
vcpu_alloc_svm(vm, &nested_gva);
vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);
hcall_page = vm_alloc_pages(vm, 1);
memset(addr_gva2hva(vm, hcall_page), 0x0, getpagesize());
+ hcall_input_page = vm_alloc_page(vm);
+ memset(addr_gva2hva(vm, hcall_input_page), 0, getpagesize());
+
+ tdp_identity_map_default_memslots(vm);
+ tdp_map(vm, L2_HCALL_INPUT_GPA, addr_gva2gpa(vm, hcall_input_page), PAGE_SIZE);
vcpu_args_set(vcpu, 3, nested_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));
vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);
--
2.52.0