[RFC PATCH v3 22/31] KVM: selftests: TDX: Add TDG.VP.INFO test

[Ackerley Tng <ackerleytng@google.com>]

From: Roger Wang <runanwang@google.com>

Adds a test for TDG.VP.INFO

Signed-off-by: Roger Wang <runanwang@google.com>
Signed-off-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
Changes RFCv2 -> RFCv3
+ Use KVM_CAP_MAX_VCPUS to set max_vcpus, check that it was passed to
  the TDX module by reading it back
---
 .../selftests/kvm/include/x86_64/tdx/tdcall.h |  19 +++
 .../selftests/kvm/include/x86_64/tdx/tdx.h    |   6 +
 .../selftests/kvm/lib/x86_64/tdx/tdcall.S     |  68 ++++++++
 .../selftests/kvm/lib/x86_64/tdx/tdx.c        |  27 ++++
 .../selftests/kvm/x86_64/tdx_vm_tests.c       | 148 ++++++++++++++++++
 5 files changed, 268 insertions(+)

diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdcall.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdcall.h
index 95fcdbd8404e9..a65ce8f3c109b 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdcall.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdcall.h
@@ -37,4 +37,23 @@ struct tdx_hypercall_args {
 /* Used to request services from the VMM */
 u64 __tdx_hypercall(struct tdx_hypercall_args *args, unsigned long flags);

+/*
+ * Used to gather the output registers values of the TDCALL and SEAMCALL
+ * instructions when requesting services from the TDX module.
+ *
+ * This is a software only structure and not part of the TDX module/VMM ABI.
+ */
+struct tdx_module_output {
+	u64 rcx;
+	u64 rdx;
+	u64 r8;
+	u64 r9;
+	u64 r10;
+	u64 r11;
+};
+
+/* Used to communicate with the TDX module */
+u64 __tdx_module_call(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9,
+		struct tdx_module_output *out);
+
 #endif // SELFTESTS_TDX_TDCALL_H
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 e746372206a25..ffab2c3ca312b 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
@@ -4,6 +4,8 @@

 #include <stdint.h>

+#define TDG_VP_INFO 1
+
 #define TDG_VP_VMCALL_GET_TD_VM_CALL_INFO 0x10000
 #define TDG_VP_VMCALL_REPORT_FATAL_ERROR 0x10003

@@ -31,4 +33,8 @@ uint64_t tdg_vp_vmcall_instruction_cpuid(uint32_t eax, uint32_t ecx,
 					uint32_t *ret_eax, uint32_t *ret_ebx,
 					uint32_t *ret_ecx, uint32_t *ret_edx);

+uint64_t tdg_vp_info(uint64_t *rcx, uint64_t *rdx,
+		uint64_t *r8, uint64_t *r9,
+		uint64_t *r10, uint64_t *r11);
+
 #endif // SELFTEST_TDX_TDX_H
diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S
index df9c1ed4bb2d1..601d715314434 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdcall.S
@@ -86,5 +86,73 @@ __tdx_hypercall:
 	pop %rbp
 	ret

+#define TDX_MODULE_rcx 0 /* offsetof(struct tdx_module_output, rcx) */
+#define TDX_MODULE_rdx 8 /* offsetof(struct tdx_module_output, rdx) */
+#define TDX_MODULE_r8 16 /* offsetof(struct tdx_module_output, r8) */
+#define TDX_MODULE_r9 24 /* offsetof(struct tdx_module_output, r9) */
+#define TDX_MODULE_r10 32 /* offsetof(struct tdx_module_output, r10) */
+#define TDX_MODULE_r11 40 /* offsetof(struct tdx_module_output, r11) */
+
+.globl __tdx_module_call
+.type __tdx_module_call, @function
+__tdx_module_call:
+	/* Set up stack frame */
+	push %rbp
+	movq %rsp, %rbp
+
+	/* Callee-saved, so preserve it */
+	push %r12
+
+	/*
+	 * Push output pointer to stack.
+	 * After the operation, it will be fetched into R12 register.
+	 */
+	push %r9
+
+	/* Mangle function call ABI into TDCALL/SEAMCALL ABI: */
+	/* Move Leaf ID to RAX */
+	mov %rdi, %rax
+	/* Move input 4 to R9 */
+	mov %r8,  %r9
+	/* Move input 3 to R8 */
+	mov %rcx, %r8
+	/* Move input 1 to RCX */
+	mov %rsi, %rcx
+	/* Leave input param 2 in RDX */
+
+	tdcall
+
+	/*
+	 * Fetch output pointer from stack to R12 (It is used
+	 * as temporary storage)
+	 */
+	pop %r12
+
+	/*
+	 * Since this macro can be invoked with NULL as an output pointer,
+	 * check if caller provided an output struct before storing output
+	 * registers.
+	 *
+	 * Update output registers, even if the call failed (RAX != 0).
+	 * Other registers may contain details of the failure.
+	 */
+	test %r12, %r12
+	jz .Lno_output_struct
+
+	/* Copy result registers to output struct: */
+	movq %rcx, TDX_MODULE_rcx(%r12)
+	movq %rdx, TDX_MODULE_rdx(%r12)
+	movq %r8,  TDX_MODULE_r8(%r12)
+	movq %r9,  TDX_MODULE_r9(%r12)
+	movq %r10, TDX_MODULE_r10(%r12)
+	movq %r11, TDX_MODULE_r11(%r12)
+
+.Lno_output_struct:
+	/* Restore the state of R12 register */
+	pop %r12
+
+	pop %rbp
+	ret
+
 /* Disable executable stack */
 .section .note.GNU-stack,"",%progbits
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 d9d60dd58dfdd..a280136634d3b 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
@@ -162,3 +162,30 @@ uint64_t tdg_vp_vmcall_instruction_cpuid(uint32_t eax, uint32_t ecx,

 	return ret;
 }
+
+uint64_t tdg_vp_info(uint64_t *rcx, uint64_t *rdx,
+		     uint64_t *r8, uint64_t *r9,
+		     uint64_t *r10, uint64_t *r11)
+{
+	uint64_t ret;
+	struct tdx_module_output out;
+
+	memset(&out, 0, sizeof(struct tdx_module_output));
+
+	ret = __tdx_module_call(TDG_VP_INFO, 0, 0, 0, 0, &out);
+
+	if (rcx)
+		*rcx = out.rcx;
+	if (rdx)
+		*rdx = out.rdx;
+	if (r8)
+		*r8 = out.r8;
+	if (r9)
+		*r9 = out.r9;
+	if (r10)
+		*r10 = out.r10;
+	if (r11)
+		*r11 = out.r11;
+
+	return ret;
+}
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 4c338206dbaf2..e2dba3b5ee63e 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -1153,6 +1153,153 @@ void verify_host_reading_private_mem(void)
 	printf("\t ... PASSED\n");
 }

+/*
+ * Do a TDG.VP.INFO call from the guest
+ */
+void guest_tdcall_vp_info(void)
+{
+	uint64_t err;
+	uint64_t rcx, rdx, r8, r9, r10, r11;
+
+	err = tdg_vp_info(&rcx, &rdx, &r8, &r9, &r10, &r11);
+	if (err)
+		tdx_test_fatal(err);
+
+	/* return values to user space host */
+	err = tdx_test_report_64bit_to_user_space(rcx);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(rdx);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r8);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r9);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r10);
+	if (err)
+		tdx_test_fatal(err);
+
+	err = tdx_test_report_64bit_to_user_space(r11);
+	if (err)
+		tdx_test_fatal(err);
+
+	tdx_test_success();
+}
+
+/*
+ * TDG.VP.INFO call from the guest. Verify the right values are returned
+ */
+void verify_tdcall_vp_info(void)
+{
+	const int num_vcpus = 2;
+	struct kvm_vcpu *vcpus[num_vcpus];
+	struct kvm_vm *vm;
+
+	uint64_t rcx, rdx, r8, r9, r10, r11;
+	uint32_t ret_num_vcpus, ret_max_vcpus;
+	uint64_t attributes;
+	uint32_t i;
+	const struct kvm_cpuid_entry2 *cpuid_entry;
+	int max_pa = -1;
+	int ret;
+
+	vm = td_create();
+
+	/* Set value for kvm->max_vcpus to be checked later */
+#define TEST_VP_INFO_MAX_VCPUS 75
+	ret = kvm_check_cap(KVM_CAP_MAX_VCPUS);
+	TEST_ASSERT(ret, "TDX: KVM_CAP_MAX_VCPUS is not supported!");
+	vm_enable_cap(vm, KVM_CAP_MAX_VCPUS, TEST_VP_INFO_MAX_VCPUS);
+
+#define TDX_TDPARAM_ATTR_SEPT_VE_DISABLE_BIT	(1UL << 28)
+#define TDX_TDPARAM_ATTR_PKS_BIT		(1UL << 30)
+	/* Setting attributes parameter used by TDH.MNG.INIT to 0x50000000 */
+	attributes = TDX_TDPARAM_ATTR_SEPT_VE_DISABLE_BIT |
+		     TDX_TDPARAM_ATTR_PKS_BIT;
+
+	td_initialize(vm, VM_MEM_SRC_ANONYMOUS, attributes);
+
+	for (i = 0; i < num_vcpus; i++)
+		vcpus[i] = td_vcpu_add(vm, i, guest_tdcall_vp_info);
+
+	td_finalize(vm);
+
+	printf("Verifying TDG.VP.INFO call:\n");
+
+	/* Get KVM CPUIDs for reference */
+	cpuid_entry = kvm_get_supported_cpuid_entry(0x80000008);
+	TEST_ASSERT(cpuid_entry, "CPUID entry missing\n");
+	max_pa = cpuid_entry->eax & 0xff;
+
+	for (i = 0; i < num_vcpus; i++) {
+		struct kvm_vcpu *vcpu = vcpus[i];
+
+		/* Wait for guest to report rcx value */
+		vcpu_run(vcpu);
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		rcx = tdx_test_read_64bit_report_from_guest(vcpu);
+
+		/* Wait for guest to report rdx value */
+		vcpu_run(vcpu);
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		rdx = tdx_test_read_64bit_report_from_guest(vcpu);
+
+		/* Wait for guest to report r8 value */
+		vcpu_run(vcpu);
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		r8 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+		/* Wait for guest to report r9 value */
+		vcpu_run(vcpu);
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		r9 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+		/* Wait for guest to report r10 value */
+		vcpu_run(vcpu);
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		r10 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+		/* Wait for guest to report r11 value */
+		vcpu_run(vcpu);
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		r11 = tdx_test_read_64bit_report_from_guest(vcpu);
+
+		ret_num_vcpus = r8 & 0xFFFFFFFF;
+		ret_max_vcpus = (r8 >> 32) & 0xFFFFFFFF;
+
+		/* first bits 5:0 of rcx represent the GPAW */
+		ASSERT_EQ(rcx & 0x3F, max_pa);
+		/* next 63:6 bits of rcx is reserved and must be 0 */
+		ASSERT_EQ(rcx >> 6, 0);
+		ASSERT_EQ(rdx, attributes);
+		ASSERT_EQ(ret_num_vcpus, num_vcpus);
+		ASSERT_EQ(ret_max_vcpus, TEST_VP_INFO_MAX_VCPUS);
+		/* VCPU_INDEX = i */
+		ASSERT_EQ(r9, i);
+		/* verify reserved registers are 0 */
+		ASSERT_EQ(r10, 0);
+		ASSERT_EQ(r11, 0);
+
+		/* Wait for guest to complete execution */
+		vcpu_run(vcpu);
+
+		TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+		TDX_TEST_ASSERT_SUCCESS(vcpu);
+
+		printf("\t ... Guest completed run on VCPU=%u\n", i);
+	}
+
+	kvm_vm_free(vm);
+	printf("\t ... PASSED\n");
+}
+
 int main(int argc, char **argv)
 {
 	setbuf(stdout, NULL);
@@ -1176,6 +1323,7 @@ int main(int argc, char **argv)
 	run_in_new_process(&verify_mmio_writes);
 	run_in_new_process(&verify_td_cpuid_tdcall);
 	run_in_new_process(&verify_host_reading_private_mem);
+	run_in_new_process(&verify_tdcall_vp_info);

 	return 0;
 }
--
2.39.0.246.g2a6d74b583-goog