Re: [RFC PATCH v5 09/29] KVM: selftests: TDX: Add report_fatal_error test

[Binbin Wu <binbin.wu@linux.intel.com>]

On 12/13/2023 4:46 AM, Sagi Shahar wrote:
> The test checks report_fatal_error functionality.
>
> Signed-off-by: Sagi Shahar <sagis@google.com>
> Signed-off-by: Ackerley Tng <ackerleytng@google.com>
> Signed-off-by: Ryan Afranji <afranji@google.com>
> ---
>   .../selftests/kvm/include/x86_64/tdx/tdx.h    |  6 ++-
>   .../kvm/include/x86_64/tdx/tdx_util.h         |  1 +
>   .../kvm/include/x86_64/tdx/test_util.h        | 19 ++++++++
>   .../selftests/kvm/lib/x86_64/tdx/tdx.c        | 39 ++++++++++++++++
>   .../selftests/kvm/lib/x86_64/tdx/tdx_util.c   | 12 +++++
>   .../selftests/kvm/lib/x86_64/tdx/test_util.c  | 10 +++++
>   .../selftests/kvm/x86_64/tdx_vm_tests.c       | 45 +++++++++++++++++++
>   7 files changed, 131 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
> index a7161efe4ee2..1340c1070002 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
> @@ -3,10 +3,14 @@
>   #define SELFTEST_TDX_TDX_H
>   
>   #include <stdint.h>
> +#include "kvm_util_base.h"
>   
> -#define TDG_VP_VMCALL_INSTRUCTION_IO 30
> +#define TDG_VP_VMCALL_REPORT_FATAL_ERROR 0x10003
>   
> +#define TDG_VP_VMCALL_INSTRUCTION_IO 30
> +void handle_userspace_tdg_vp_vmcall_exit(struct kvm_vcpu *vcpu);
>   uint64_t tdg_vp_vmcall_instruction_io(uint64_t port, uint64_t size,
>   				      uint64_t write, uint64_t *data);
> +void tdg_vp_vmcall_report_fatal_error(uint64_t error_code, uint64_t data_gpa);
>   
>   #endif // SELFTEST_TDX_TDX_H
> diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h
> index 274b245f200b..32dd6b8fda46 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx_util.h
> @@ -12,5 +12,6 @@ struct kvm_vm *td_create(void);
>   void td_initialize(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type,
>   		   uint64_t attributes);
>   void td_finalize(struct kvm_vm *vm);
> +void td_vcpu_run(struct kvm_vcpu *vcpu);
>   
>   #endif // SELFTESTS_TDX_KVM_UTIL_H
> diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h b/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h
> index b570b6d978ff..6d69921136bd 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/tdx/test_util.h
> @@ -49,4 +49,23 @@ bool is_tdx_enabled(void);
>    */
>   void tdx_test_success(void);
>   
> +/**
> + * Report an error with @error_code to userspace.
> + *
> + * Return value from tdg_vp_vmcall_report_fatal_error is ignored since execution
> + * is not expected to continue beyond this point.
> + */
> +void tdx_test_fatal(uint64_t error_code);
> +
> +/**
> + * Report an error with @error_code to userspace.
> + *
> + * @data_gpa may point to an optional shared guest memory holding the error
> + * string.
> + *
> + * Return value from tdg_vp_vmcall_report_fatal_error is ignored since execution
> + * is not expected to continue beyond this point.
> + */
> +void tdx_test_fatal_with_data(uint64_t error_code, uint64_t data_gpa);
> +
>   #endif // SELFTEST_TDX_TEST_UTIL_H
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
> index c2414523487a..b854c3aa34ff 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
> @@ -1,8 +1,31 @@
>   // SPDX-License-Identifier: GPL-2.0-only
>   
> +#include <string.h>
> +
>   #include "tdx/tdcall.h"
>   #include "tdx/tdx.h"
>   
> +void handle_userspace_tdg_vp_vmcall_exit(struct kvm_vcpu *vcpu)
> +{
> +	struct kvm_tdx_vmcall *vmcall_info = &vcpu->run->tdx.u.vmcall;
> +	uint64_t vmcall_subfunction = vmcall_info->subfunction;
> +
> +	switch (vmcall_subfunction) {
> +	case TDG_VP_VMCALL_REPORT_FATAL_ERROR:
> +		vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
> +		vcpu->run->system_event.ndata = 3;
> +		vcpu->run->system_event.data[0] =
> +			TDG_VP_VMCALL_REPORT_FATAL_ERROR;
> +		vcpu->run->system_event.data[1] = vmcall_info->in_r12;
> +		vcpu->run->system_event.data[2] = vmcall_info->in_r13;
> +		vmcall_info->status_code = 0;
> +		break;
> +	default:
> +		TEST_FAIL("TD VMCALL subfunction %lu is unsupported.\n",
> +			  vmcall_subfunction);
> +	}
> +}
> +
>   uint64_t tdg_vp_vmcall_instruction_io(uint64_t port, uint64_t size,
>   				      uint64_t write, uint64_t *data)
>   {
> @@ -25,3 +48,19 @@ uint64_t tdg_vp_vmcall_instruction_io(uint64_t port, uint64_t size,
>   
>   	return ret;
>   }
> +
> +void tdg_vp_vmcall_report_fatal_error(uint64_t error_code, uint64_t data_gpa)
> +{
> +	struct tdx_hypercall_args args;
> +
> +	memset(&args, 0, sizeof(struct tdx_hypercall_args));
> +
> +	if (data_gpa)
> +		error_code |= 0x8000000000000000;
> +
> +	args.r11 = TDG_VP_VMCALL_REPORT_FATAL_ERROR;
> +	args.r12 = error_code;
> +	args.r13 = data_gpa;
> +
> +	__tdx_hypercall(&args, 0);
> +}
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c
> index b302060049d5..d745bb6287c1 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx_util.c
> @@ -10,6 +10,7 @@
>   
>   #include "kvm_util.h"
>   #include "test_util.h"
> +#include "tdx/tdx.h"
>   #include "tdx/td_boot.h"
>   #include "kvm_util_base.h"
>   #include "processor.h"
> @@ -519,3 +520,14 @@ void td_finalize(struct kvm_vm *vm)
>   
>   	tdx_td_finalizemr(vm);
>   }
> +
> +void td_vcpu_run(struct kvm_vcpu *vcpu)
> +{
> +	vcpu_run(vcpu);
> +
> +	/* Handle TD VMCALLs that require userspace handling. */
> +	if (vcpu->run->exit_reason == KVM_EXIT_TDX &&
> +	    vcpu->run->tdx.type == KVM_EXIT_TDX_VMCALL) {
> +		handle_userspace_tdg_vp_vmcall_exit(vcpu);
> +	}
> +}
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c
> index 6905d0ca3877..7f3cd8089cea 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/test_util.c
> @@ -32,3 +32,13 @@ void tdx_test_success(void)
>   				     TDX_TEST_SUCCESS_SIZE,
>   				     TDG_VP_VMCALL_INSTRUCTION_IO_WRITE, &code);
>   }
> +
> +void tdx_test_fatal_with_data(uint64_t error_code, uint64_t data_gpa)
> +{
> +	tdg_vp_vmcall_report_fatal_error(error_code, data_gpa);
> +}
> +
> +void tdx_test_fatal(uint64_t error_code)
> +{
> +	tdx_test_fatal_with_data(error_code, 0);
> +}
> 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 a18d1c9d6026..8638c7bbedaa 100644
> --- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
> +++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
> @@ -2,6 +2,7 @@
>   
>   #include <signal.h>
>   #include "kvm_util_base.h"
> +#include "tdx/tdx.h"
>   #include "tdx/tdx_util.h"
>   #include "tdx/test_util.h"
>   #include "test_util.h"
> @@ -30,6 +31,49 @@ void verify_td_lifecycle(void)
>   	printf("\t ... PASSED\n");
>   }
>   
> +void guest_code_report_fatal_error(void)
> +{
> +	uint64_t err;
> +
> +	/*
> +	 * Note: err should follow the GHCI spec definition:
> +	 * bits 31:0 should be set to 0.
> +	 * bits 62:32 are used for TD-specific extended error code.
> +	 * bit 63 is used to mark additional information in shared memory.
> +	 */
> +	err = 0x0BAAAAAD00000000;
> +	if (err)
> +		tdx_test_fatal(err);

Nit:
Since the error code is a constant, no need to use if statement.
Or even save the variable?


> +
> +	tdx_test_success();
> +}
> +void verify_report_fatal_error(void)
> +{
> +	struct kvm_vm *vm;
> +	struct kvm_vcpu *vcpu;
> +
> +	vm = td_create();
> +	td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
> +	vcpu = td_vcpu_add(vm, 0, guest_code_report_fatal_error);
> +	td_finalize(vm);
> +
> +	printf("Verifying report_fatal_error:\n");
> +
> +	td_vcpu_run(vcpu);
> +
> +	TEST_ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_SYSTEM_EVENT);
> +	TEST_ASSERT_EQ(vcpu->run->system_event.ndata, 3);
> +	TEST_ASSERT_EQ(vcpu->run->system_event.data[0], TDG_VP_VMCALL_REPORT_FATAL_ERROR);
> +	TEST_ASSERT_EQ(vcpu->run->system_event.data[1], 0x0BAAAAAD00000000);
> +	TEST_ASSERT_EQ(vcpu->run->system_event.data[2], 0);
> +
> +	vcpu_run(vcpu);
> +	TDX_TEST_ASSERT_SUCCESS(vcpu);
> +
> +	kvm_vm_free(vm);
> +	printf("\t ... PASSED\n");
> +}
> +
>   int main(int argc, char **argv)
>   {
>   	setbuf(stdout, NULL);
> @@ -40,6 +84,7 @@ int main(int argc, char **argv)
>   	}
>   
>   	run_in_new_process(&verify_td_lifecycle);
> +	run_in_new_process(&verify_report_fatal_error);
>   
>   	return 0;
>   }