[PATCH v4 10/25] KVM: selftests: Enable TSC scaling in evmcs selftest

Vitaly Kuznetsov
2022-07-14T09:14:46Z

The updated Enlightened VMCS v1 definition enables TSC scaling, test
that SECONDARY_EXEC_TSC_SCALING can now be enabled.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
.../testing/selftests/kvm/x86_64/evmcs_test.c | 31 +++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/evmcs_test.c b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
index 8dda527cc080..80135b98dc3b 100644
--- a/tools/testing/selftests/kvm/x86_64/evmcs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/evmcs_test.c
@@ -18,6 +18,9 @@

#include "vmx.h"

+/* Test flags */
+#define HOST_HAS_TSC_SCALING BIT(0)
+
static int ud_count;

static void guest_ud_handler(struct ex_regs *regs)
@@ -64,11 +67,14 @@ void l2_guest_code(void)
vmcall();
rdmsr_gs_base(); /* intercepted */

+ /* TSC scaling */
+ vmcall();
+
/* Done, exit to L1 and never come back. */
vmcall();
}

-void guest_code(struct vmx_pages *vmx_pages)
+void guest_code(struct vmx_pages *vmx_pages, u64 test_flags)
{
#define L2_GUEST_STACK_SIZE 64
unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
@@ -150,6 +156,18 @@ void guest_code(struct vmx_pages *vmx_pages)
GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
GUEST_SYNC(11);

+ if (test_flags & HOST_HAS_TSC_SCALING) {
+ GUEST_ASSERT((rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32) &
+ SECONDARY_EXEC_TSC_SCALING);
+ /* Try enabling TSC scaling */
+ vmwrite(SECONDARY_VM_EXEC_CONTROL, vmreadz(SECONDARY_VM_EXEC_CONTROL) |
+ SECONDARY_EXEC_TSC_SCALING);
+ vmwrite(TSC_MULTIPLIER, 1);
+ }
+ GUEST_ASSERT(!vmresume());
+ GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
+ GUEST_SYNC(12);
+
/* Try enlightened vmptrld with an incorrect GPA */
evmcs_vmptrld(0xdeadbeef, vmx_pages->enlightened_vmcs);
GUEST_ASSERT(vmlaunch());
@@ -204,6 +222,7 @@ int main(int argc, char *argv[])
struct kvm_vm *vm;
struct kvm_run *run;
struct ucall uc;
+ u64 test_flags = 0;
int stage;

vm = vm_create_with_one_vcpu(&vcpu, guest_code);
@@ -212,11 +231,19 @@ 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));

+ if ((kvm_get_feature_msr(MSR_IA32_VMX_PROCBASED_CTLS2) >> 32) &
+ SECONDARY_EXEC_TSC_SCALING) {
+ test_flags |= HOST_HAS_TSC_SCALING;
+ pr_info("TSC scaling is supported, adding to test\n");
+ } else {
+ pr_info("TSC scaling is not supported\n");
+ }
+
vcpu_set_hv_cpuid(vcpu);
vcpu_enable_evmcs(vcpu);

vcpu_alloc_vmx(vm, &vmx_pages_gva);
- vcpu_args_set(vcpu, 1, vmx_pages_gva);
+ vcpu_args_set(vcpu, 2, vmx_pages_gva, test_flags);

vm_init_descriptor_tables(vm);
vcpu_init_descriptor_tables(vcpu);
--
2.35.3