Re: [RFC PATCH v5 12/29] KVM: selftests: TDX: Add basic get_td_vmcall_info test

Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> · Fri, 1 Mar 2024 14:03:43 +0800

On 12/13/2023 4:46 AM, Sagi Shahar wrote:
The test calls get_td_vmcall_info from the guest and verifies the
expected returned values.

Signed-off-by: Sagi Shahar <sagis@xxxxxxxxxx>
Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
Signed-off-by: Ryan Afranji <afranji@xxxxxxxxxx>
---
  .../selftests/kvm/include/x86_64/tdx/tdx.h    |  3 +
  .../kvm/include/x86_64/tdx/test_util.h        | 27 +++++++
  .../selftests/kvm/lib/x86_64/tdx/tdx.c        | 23 ++++++
  .../selftests/kvm/lib/x86_64/tdx/test_util.c  | 46 +++++++++++
  .../selftests/kvm/x86_64/tdx_vm_tests.c       | 80 +++++++++++++++++++
  5 files changed, 179 insertions(+)

Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>

Also, does it need to add another case for the non-zero value of r12 to
test the VMCALL_INVALID_OPERAND path?

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 1340c1070002..63788012bf94 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
@@ -5,6 +5,7 @@
  #include <stdint.h>
  #include "kvm_util_base.h"
  
+#define TDG_VP_VMCALL_GET_TD_VM_CALL_INFO 0x10000
  #define TDG_VP_VMCALL_REPORT_FATAL_ERROR 0x10003
  
  #define TDG_VP_VMCALL_INSTRUCTION_IO 30
@@ -12,5 +13,7 @@ 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);
+uint64_t tdg_vp_vmcall_get_td_vmcall_info(uint64_t *r11, uint64_t *r12,
+					uint64_t *r13, uint64_t *r14);
  
  #endif // SELFTEST_TDX_TDX_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 af0ddbfe8d71..8a9b6a1bec3e 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
@@ -4,6 +4,7 @@
  
  #include <stdbool.h>
  
+#include "kvm_util_base.h"
  #include "tdcall.h"
  
  #define TDX_TEST_SUCCESS_PORT 0x30
@@ -111,4 +112,30 @@ void tdx_test_fatal_with_data(uint64_t error_code, uint64_t data_gpa);
   */
  uint64_t tdx_test_report_to_user_space(uint32_t data);
  
+/**
+ * Report a 64 bit value from the guest to user space using TDG.VP.VMCALL
+ * <Instruction.IO> call.
+ *
+ * Data is sent to host in 2 calls. LSB is sent (and needs to be read) first.
+ */
+uint64_t tdx_test_send_64bit(uint64_t port, uint64_t data);
+
+/**
+ * Report a 64 bit value from the guest to user space using TDG.VP.VMCALL
+ * <Instruction.IO> call. Data is reported on port TDX_TEST_REPORT_PORT.
+ */
+uint64_t tdx_test_report_64bit_to_user_space(uint64_t data);
+
+/**
+ * Read a 64 bit value from the guest in user space, sent using
+ * tdx_test_send_64bit().
+ */
+uint64_t tdx_test_read_64bit(struct kvm_vcpu *vcpu, uint64_t port);
+
+/**
+ * Read a 64 bit value from the guest in user space, sent using
+ * tdx_test_report_64bit_to_user_space.
+ */
+uint64_t tdx_test_read_64bit_report_from_guest(struct kvm_vcpu *vcpu);
+
  #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 b854c3aa34ff..e5a9e13c62e2 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
@@ -64,3 +64,26 @@ void tdg_vp_vmcall_report_fatal_error(uint64_t error_code, uint64_t data_gpa)
  
  	__tdx_hypercall(&args, 0);
  }
+
+uint64_t tdg_vp_vmcall_get_td_vmcall_info(uint64_t *r11, uint64_t *r12,
+					uint64_t *r13, uint64_t *r14)
+{
+	uint64_t ret;
+	struct tdx_hypercall_args args = {
+		.r11 = TDG_VP_VMCALL_GET_TD_VM_CALL_INFO,
+		.r12 = 0,
+	};
+
+	ret = __tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT);
+
+	if (r11)
+		*r11 = args.r11;
+	if (r12)
+		*r12 = args.r12;
+	if (r13)
+		*r13 = args.r13;
+	if (r14)
+		*r14 = args.r14;
+
+	return ret;
+}
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 55c5a1e634df..3ae651cd5fac 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
@@ -7,6 +7,7 @@
  #include <unistd.h>
  
  #include "kvm_util_base.h"
+#include "tdx/tdcall.h"
  #include "tdx/tdx.h"
  #include "tdx/test_util.h"
  
@@ -53,3 +54,48 @@ uint64_t tdx_test_report_to_user_space(uint32_t data)
  					TDG_VP_VMCALL_INSTRUCTION_IO_WRITE,
  					&data_64);
  }
+
+uint64_t tdx_test_send_64bit(uint64_t port, uint64_t data)
+{
+	uint64_t err;
+	uint64_t data_lo = data & 0xFFFFFFFF;
+	uint64_t data_hi = (data >> 32) & 0xFFFFFFFF;
+
+	err = tdg_vp_vmcall_instruction_io(port, 4,
+					   TDG_VP_VMCALL_INSTRUCTION_IO_WRITE,
+					   &data_lo);
+	if (err)
+		return err;
+
+	return tdg_vp_vmcall_instruction_io(port, 4,
+					    TDG_VP_VMCALL_INSTRUCTION_IO_WRITE,
+					    &data_hi);
+}
+
+uint64_t tdx_test_report_64bit_to_user_space(uint64_t data)
+{
+	return tdx_test_send_64bit(TDX_TEST_REPORT_PORT, data);
+}
+
+uint64_t tdx_test_read_64bit(struct kvm_vcpu *vcpu, uint64_t port)
+{
+	uint32_t lo, hi;
+	uint64_t res;
+
+	TDX_TEST_ASSERT_IO(vcpu, port, 4, TDG_VP_VMCALL_INSTRUCTION_IO_WRITE);
+	lo = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset);
+
+	vcpu_run(vcpu);
+
+	TDX_TEST_ASSERT_IO(vcpu, port, 4, TDG_VP_VMCALL_INSTRUCTION_IO_WRITE);
+	hi = *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset);
+
+	res = hi;
+	res = (res << 32) | lo;
+	return res;
+}
+
+uint64_t tdx_test_read_64bit_report_from_guest(struct kvm_vcpu *vcpu)
+{
+	return tdx_test_read_64bit(vcpu, TDX_TEST_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 1b30e6f5a569..569c8fb0a59f 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -260,6 +260,85 @@ void verify_td_cpuid(void)
  	printf("\t ... PASSED\n");
  }
  
+/*
+ * Verifies get_td_vmcall_info functionality.
+ */
+void guest_code_get_td_vmcall_info(void)
+{
+	uint64_t err;
+	uint64_t r11, r12, r13, r14;
+
+	err = tdg_vp_vmcall_get_td_vmcall_info(&r11, &r12, &r13, &r14);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r11);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r12);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r13);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r14);
+	if (err)
+		tdx_test_fatal(err);
+
+	tdx_test_success();
+}
+
+void verify_get_td_vmcall_info(void)
+{
+	struct kvm_vm *vm;
+	struct kvm_vcpu *vcpu;
+
+	uint64_t r11, r12, r13, r14;
+
+	vm = td_create();
+	td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
+	vcpu = td_vcpu_add(vm, 0, guest_code_get_td_vmcall_info);
+	td_finalize(vm);
+
+	printf("Verifying TD get vmcall info:\n");
+
+	/* Wait for guest to report r11 value */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	r11 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+	/* Wait for guest to report r12 value */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	r12 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+	/* Wait for guest to report r13 value */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	r13 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+	/* Wait for guest to report r14 value */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	r14 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+	TEST_ASSERT_EQ(r11, 0);
+	TEST_ASSERT_EQ(r12, 0);
+	TEST_ASSERT_EQ(r13, 0);
+	TEST_ASSERT_EQ(r14, 0);
+
+	/* Wait for guest to complete execution */
+	td_vcpu_run(vcpu);
+	TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+	TDX_TEST_ASSERT_SUCCESS(vcpu);
+
+	kvm_vm_free(vm);
+	printf("\t ... PASSED\n");
+}
+
  int main(int argc, char **argv)
  {
  	setbuf(stdout, NULL);
@@ -273,6 +352,7 @@ 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_get_td_vmcall_info);
  
  	return 0;
  }








