This test issues a CPUID TDVMCALL from inside the guest to get the CPUID values as seen by KVM.
Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/lib/x86_64/tdx.h | 23 ++++ .../selftests/kvm/x86_64/tdx_vm_tests.c | 102 ++++++++++++++++++ 2 files changed, 125 insertions(+)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx.h b/tools/testing/selftests/kvm/lib/x86_64/tdx.h index 17e3649e5729..3729543a05a3 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/tdx.h +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx.h @@ -56,6 +56,7 @@
#define TDX_GET_TD_VM_CALL_INFO 0x10000 #define TDX_REPORT_FATAL_ERROR 0x10003 +#define TDX_INSTRUCTION_CPUID 10 #define TDX_INSTRUCTION_HLT 12 #define TDX_INSTRUCTION_IO 30 #define TDX_INSTRUCTION_RDMSR 31 @@ -347,6 +348,28 @@ static inline uint64_t tdvmcall_mmio_write(uint64_t address, uint64_t size, uint return regs.r10; }
+/* + * Execute CPUID instruction. + */ +static inline uint64_t tdvmcall_cpuid(uint32_t eax, uint32_t ecx, + uint32_t *ret_eax, uint32_t *ret_ebx, + uint32_t *ret_ecx, uint32_t *ret_edx) +{ + struct kvm_regs regs; + + memset(®s, 0, sizeof(regs)); + regs.r11 = TDX_INSTRUCTION_CPUID; + regs.r12 = eax; + regs.r13 = ecx; + regs.rcx = 0xFC00; + tdcall(®s); + *ret_eax = regs.r12; + *ret_ebx = regs.r13; + *ret_ecx = regs.r14; + *ret_edx = regs.r15; + return regs.r10; +} + /* * Reports a 32 bit value from the guest to user space using a TDVM IO call. * Data is reported on port TDX_DATA_REPORT_PORT. diff --git a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c index 382119bd444b..934f2f7a5df9 100644 --- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c +++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c @@ -459,6 +459,107 @@ void verify_td_cpuid(void) printf("\t ... PASSED\n"); }
+/* + * Verifies CPUID TDVMCALL functionality. + * The guest will then send the values to userspace using an IO write to be + * checked against the expected values. + */ +TDX_GUEST_FUNCTION(guest_code_cpuid_tdcall) +{ + uint64_t err; + uint32_t eax, ebx, ecx, edx; + + // Read CPUID leaf 0x1 from host. + err = tdvmcall_cpuid(/*eax=*/1, /*ecx=*/0, &eax, &ebx, &ecx, &edx); + if (err) + tdvmcall_fatal(err); + + err = tdvm_report_to_user_space(eax); + if (err) + tdvmcall_fatal(err); + + err = tdvm_report_to_user_space(ebx); + if (err) + tdvmcall_fatal(err); + + err = tdvm_report_to_user_space(ecx); + if (err) + tdvmcall_fatal(err); + + err = tdvm_report_to_user_space(edx); + if (err) + tdvmcall_fatal(err); + + tdvmcall_success(); +} + +void verify_td_cpuid_tdcall(void) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + uint32_t eax, ebx, ecx, edx; + struct kvm_cpuid_entry2 *cpuid_entry; + struct tdx_cpuid_data cpuid_data; + int ret; + + printf("Verifying TD CPUID TDVMCALL:\n"); + /* Create a TD VM with no memory.*/ + vm = vm_create_tdx(); + + /* Allocate TD guest memory and initialize the TD.*/ + initialize_td(vm); + + /* Initialize the TD vcpu and copy the test code to the guest memory.*/ + vcpu = vm_vcpu_add_tdx(vm, 0); + + /* Setup and initialize VM memory */ + prepare_source_image(vm, guest_code_cpuid_tdcall, + TDX_FUNCTION_SIZE(guest_code_cpuid_tdcall), 0); + finalize_td_memory(vm); + + /* Wait for guest to report CPUID values */ + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_IO(vcpu, TDX_DATA_REPORT_PORT, 4, TDX_IO_WRITE); + eax = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_IO(vcpu, TDX_DATA_REPORT_PORT, 4, TDX_IO_WRITE); + ebx = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_IO(vcpu, TDX_DATA_REPORT_PORT, 4, TDX_IO_WRITE); + ecx = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_IO(vcpu, TDX_DATA_REPORT_PORT, 4, TDX_IO_WRITE); + edx = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_GUEST_COMPLETION(vcpu); + + /* Get KVM CPUIDs for reference */ + memset(&cpuid_data, 0, sizeof(cpuid_data)); + cpuid_data.cpuid.nent = KVM_MAX_CPUID_ENTRIES; + ret = ioctl(vm->kvm_fd, KVM_GET_SUPPORTED_CPUID, &cpuid_data); + TEST_ASSERT(!ret, "KVM_GET_SUPPORTED_CPUID failed\n"); + cpuid_entry = find_cpuid_entry(cpuid_data, 1, 0); + TEST_ASSERT(cpuid_entry, "CPUID entry missing\n"); + + ASSERT_EQ(cpuid_entry->eax, eax); + // Mask lapic ID when comparing ebx. + ASSERT_EQ(cpuid_entry->ebx & ~0xFF000000, ebx & ~0xFF000000); + ASSERT_EQ(cpuid_entry->ecx, ecx); + ASSERT_EQ(cpuid_entry->edx, edx); + + kvm_vm_free(vm); + printf("\t ... PASSED\n"); +} + /* * Verifies get_td_vmcall_info functionality. */ @@ -1184,6 +1285,7 @@ int main(int argc, char **argv) run_in_new_process(&verify_report_fatal_error); run_in_new_process(&verify_td_ioexit); run_in_new_process(&verify_td_cpuid); + run_in_new_process(&verify_td_cpuid_tdcall); run_in_new_process(&verify_get_td_vmcall_info); run_in_new_process(&verify_guest_writes); run_in_new_process(&verify_guest_reads);