| Message ID | 20240228101837.93642-4-vkuznets@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Fix KVM_FEATURE_PV_UNHALT update logic | expand |
Shortlog is a wee bit long, I went with: KVM: selftests: Check that PV_UNHALT is cleared when HLT exiting is disabled On Wed, Feb 28, 2024, Vitaly Kuznetsov wrote: > KVM_FEATURE_PV_UNHALT is expected to get cleared from KVM PV feature CPUID > data when KVM_X86_DISABLE_EXITS_HLT is enabled. Add the corresponding test > to kvm_pv_test. > > Note, the newly added code doesn't actually test KVM_FEATURE_PV_UNHALT and > KVM_X86_DISABLE_EXITS_HLT features. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- ... > + TEST_ASSERT(ent->eax & (1 << KVM_FEATURE_PV_UNHALT), > + "Enabling X86_FEATURE_KVM_PV_UNHALT had no effect"); > + > + /* Make sure KVM clears vcpu->arch.kvm_cpuid */ > + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_SIGNATURE); > + kvm_sig_old = ent->ebx; > + ent->ebx = 0xdeadbeef; > + vcpu_set_cpuid(vcpu); > + > + vm_enable_cap(vm, KVM_CAP_X86_DISABLE_EXITS, KVM_X86_DISABLE_EXITS_HLT); > + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_SIGNATURE); > + ent->ebx = kvm_sig_old; > + vcpu_set_cpuid(vcpu); > + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_FEATURES); > + > + TEST_ASSERT(!(ent->eax & (1 << KVM_FEATURE_PV_UNHALT)), X86_FEATURE_KVM_PV_UNHALT already exists, all we're missing is a helper to get a CPUID feature from host userspace given a vCPU. I added this static inline bool vcpu_cpuid_has(struct kvm_vcpu *vcpu, struct kvm_x86_cpu_feature feature) { struct kvm_cpuid_entry2 *entry; entry = __vcpu_get_cpuid_entry(vcpu, feature.function, feature.index); return *((&entry->eax) + feature.reg) & BIT(feature.bit); } and used it in this test instead of open coding the reg+bit.
diff --git a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c index 9e2879af7c20..60399454b45e 100644 --- a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c @@ -133,6 +133,46 @@ static void enter_guest(struct kvm_vcpu *vcpu) } } +static void test_pv_unhalt(void) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct kvm_cpuid_entry2 *ent; + u32 kvm_sig_old; + + pr_info("testing KVM_FEATURE_PV_UNHALT\n"); + + TEST_REQUIRE(KVM_CAP_X86_DISABLE_EXITS); + + /* KVM_PV_UNHALT test */ + vm = vm_create_with_one_vcpu(&vcpu, guest_main); + vcpu_set_cpuid_feature(vcpu, X86_FEATURE_KVM_PV_UNHALT); + + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_FEATURES); + + TEST_ASSERT(ent->eax & (1 << KVM_FEATURE_PV_UNHALT), + "Enabling X86_FEATURE_KVM_PV_UNHALT had no effect"); + + /* Make sure KVM clears vcpu->arch.kvm_cpuid */ + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_SIGNATURE); + kvm_sig_old = ent->ebx; + ent->ebx = 0xdeadbeef; + vcpu_set_cpuid(vcpu); + + vm_enable_cap(vm, KVM_CAP_X86_DISABLE_EXITS, KVM_X86_DISABLE_EXITS_HLT); + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_SIGNATURE); + ent->ebx = kvm_sig_old; + vcpu_set_cpuid(vcpu); + ent = vcpu_get_cpuid_entry(vcpu, KVM_CPUID_FEATURES); + + TEST_ASSERT(!(ent->eax & (1 << KVM_FEATURE_PV_UNHALT)), + "KVM_FEATURE_PV_UNHALT is set with KVM_CAP_X86_DISABLE_EXITS"); + + /* FIXME: actually test KVM_FEATURE_PV_UNHALT feature */ + + kvm_vm_free(vm); +} + int main(void) { struct kvm_vcpu *vcpu; @@ -151,4 +191,6 @@ int main(void) enter_guest(vcpu); kvm_vm_free(vm); + + test_pv_unhalt(); }
KVM_FEATURE_PV_UNHALT is expected to get cleared from KVM PV feature CPUID data when KVM_X86_DISABLE_EXITS_HLT is enabled. Add the corresponding test to kvm_pv_test. Note, the newly added code doesn't actually test KVM_FEATURE_PV_UNHALT and KVM_X86_DISABLE_EXITS_HLT features. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- .../selftests/kvm/x86_64/kvm_pv_test.c | 42 +++++++++++++++++++ 1 file changed, 42 insertions(+)