[RFC PATCH v3 18/31] KVM: selftests: TDX: Add TDX MMIO reads test

Ackerley Tng
2023-01-21T00:18:40Z

From: Sagi Shahar <sagis@google.com>

The test verifies MMIO reads of various sizes from the host to the guest.

Signed-off-by: Sagi Shahar <sagis@google.com>
Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
.../selftests/kvm/include/x86_64/tdx/tdcall.h | 2 +
.../selftests/kvm/include/x86_64/tdx/tdx.h | 3 +
.../kvm/include/x86_64/tdx/test_util.h | 23 +++++
.../selftests/kvm/lib/x86_64/tdx/tdx.c | 19 ++++
.../selftests/kvm/x86_64/tdx_vm_tests.c | 87 +++++++++++++++++++
5 files changed, 134 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 b5e94b7c48fa5..95fcdbd8404e9 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdcall.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdcall.h
@@ -9,6 +9,8 @@

#define TDG_VP_VMCALL_INSTRUCTION_IO_READ 0
#define TDG_VP_VMCALL_INSTRUCTION_IO_WRITE 1
+#define TDG_VP_VMCALL_VE_REQUEST_MMIO_READ 0
+#define TDG_VP_VMCALL_VE_REQUEST_MMIO_WRITE 1

#define TDG_VP_VMCALL_SUCCESS 0x0000000000000000
#define TDG_VP_VMCALL_INVALID_OPERAND 0x8000000000000000
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 7eba9d80b3681..8dd6a65485260 100644
--- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
+++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h
@@ -11,6 +11,7 @@
#define TDG_VP_VMCALL_INSTRUCTION_IO 30
#define TDG_VP_VMCALL_INSTRUCTION_RDMSR 31
#define TDG_VP_VMCALL_INSTRUCTION_WRMSR 32
+#define TDG_VP_VMCALL_VE_REQUEST_MMIO 48

uint64_t tdg_vp_vmcall_instruction_io(uint64_t port, uint64_t size,
@@ -21,5 +22,7 @@ uint64_t tdg_vp_vmcall_get_td_vmcall_info(uint64_t *r11, uint64_t *r12,
uint64_t tdg_vp_vmcall_instruction_rdmsr(uint64_t index, uint64_t *ret_value);
uint64_t tdg_vp_vmcall_instruction_wrmsr(uint64_t index, uint64_t value);
uint64_t tdg_vp_vmcall_instruction_hlt(uint64_t interrupt_blocked_flag);
+uint64_t tdg_vp_vmcall_ve_request_mmio_read(uint64_t address, uint64_t size,
+ uint64_t *data_out);

#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 8a9b6a1bec3eb..af412b7646049 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
@@ -35,6 +35,29 @@
(VCPU)->run->io.direction); \
} while (0)

+
+/**
+ * Assert that some MMIO operation involving TDG.VP.VMCALL <#VERequestMMIO> was
+ * called in the guest.
+ */
+#define TDX_TEST_ASSERT_MMIO(VCPU, ADDR, SIZE, DIR) \
+ do { \
+ TEST_ASSERT((VCPU)->run->exit_reason == KVM_EXIT_MMIO, \
+ "Got exit_reason other than KVM_EXIT_MMIO: %u (%s)\n", \
+ (VCPU)->run->exit_reason, \
+ exit_reason_str((VCPU)->run->exit_reason)); \
+ \
+ TEST_ASSERT(((VCPU)->run->exit_reason == KVM_EXIT_MMIO) && \
+ ((VCPU)->run->mmio.phys_addr == (ADDR)) && \
+ ((VCPU)->run->mmio.len == (SIZE)) && \
+ ((VCPU)->run->mmio.is_write == (DIR)), \
+ "Got an unexpected MMIO exit values: %u (%s) %llu %d %d\n", \
+ (VCPU)->run->exit_reason, \
+ exit_reason_str((VCPU)->run->exit_reason), \
+ (VCPU)->run->mmio.phys_addr, (VCPU)->run->mmio.len, \
+ (VCPU)->run->mmio.is_write); \
+ } while (0)
+
/**
* Check and report if there was some failure in the guest, either an exception
* like a triple fault, or if a tdx_test_fatal() was hit.
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 1af0626c2a4ad..dcdacf08bcd60 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c
@@ -103,3 +103,22 @@ uint64_t tdg_vp_vmcall_instruction_hlt(uint64_t interrupt_blocked_flag)

return __tdx_hypercall(&args, 0);
}
+
+uint64_t tdg_vp_vmcall_ve_request_mmio_read(uint64_t address, uint64_t size,
+ uint64_t *data_out)
+{
+ uint64_t ret;
+ struct tdx_hypercall_args args = {
+ .r11 = TDG_VP_VMCALL_VE_REQUEST_MMIO,
+ .r12 = size,
+ .r13 = TDG_VP_VMCALL_VE_REQUEST_MMIO_READ,
+ .r14 = address,
+ };
+
+ ret = __tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT);
+
+ if (data_out)
+ *data_out = args.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 346c1e07af9c0..88f0429db0176 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c
@@ -806,6 +806,92 @@ void verify_guest_hlt(void)
_verify_guest_hlt(0);
}

+/* Pick any address that was not mapped into the guest to test MMIO */
+#define TDX_MMIO_TEST_ADDR 0x200000000
+
+void guest_mmio_reads(void)
+{
+ uint64_t data;
+ uint64_t ret;
+
+ ret = tdg_vp_vmcall_ve_request_mmio_read(TDX_MMIO_TEST_ADDR, 1, &data);
+ if (ret)
+ tdx_test_fatal(ret);
+ if (data != 0x12)
+ tdx_test_fatal(1);
+
+ ret = tdg_vp_vmcall_ve_request_mmio_read(TDX_MMIO_TEST_ADDR, 2, &data);
+ if (ret)
+ tdx_test_fatal(ret);
+ if (data != 0x1234)
+ tdx_test_fatal(2);
+
+ ret = tdg_vp_vmcall_ve_request_mmio_read(TDX_MMIO_TEST_ADDR, 4, &data);
+ if (ret)
+ tdx_test_fatal(ret);
+ if (data != 0x12345678)
+ tdx_test_fatal(4);
+
+ ret = tdg_vp_vmcall_ve_request_mmio_read(TDX_MMIO_TEST_ADDR, 8, &data);
+ if (ret)
+ tdx_test_fatal(ret);
+ if (data != 0x1234567890ABCDEF)
+ tdx_test_fatal(8);
+
+ // Read an invalid number of bytes.
+ ret = tdg_vp_vmcall_ve_request_mmio_read(TDX_MMIO_TEST_ADDR, 10, &data);
+ if (ret)
+ tdx_test_fatal(ret);
+
+ tdx_test_success();
+}
+
+/*
+ * Varifies guest MMIO reads.
+ */
+void verify_mmio_reads(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_mmio_reads);
+ td_finalize(vm);
+
+ printf("Verifying TD MMIO reads:\n");
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 1, TDG_VP_VMCALL_VE_REQUEST_MMIO_READ);
+ *(uint8_t *)vcpu->run->mmio.data = 0x12;
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 2, TDG_VP_VMCALL_VE_REQUEST_MMIO_READ);
+ *(uint16_t *)vcpu->run->mmio.data = 0x1234;
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 4, TDG_VP_VMCALL_VE_REQUEST_MMIO_READ);
+ *(uint32_t *)vcpu->run->mmio.data = 0x12345678;
+
+ vcpu_run(vcpu);
+ TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
+ TDX_TEST_ASSERT_MMIO(vcpu, TDX_MMIO_TEST_ADDR, 8, TDG_VP_VMCALL_VE_REQUEST_MMIO_READ);
+ *(uint64_t *)vcpu->run->mmio.data = 0x1234567890ABCDEF;
+
+ vcpu_run(vcpu);
+ ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_SYSTEM_EVENT);
+ ASSERT_EQ(vcpu->run->system_event.data[1], TDG_VP_VMCALL_INVALID_OPERAND);
+
+ 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);
@@ -825,6 +911,7 @@ int main(int argc, char **argv)
run_in_new_process(&verify_guest_msr_writes);
run_in_new_process(&verify_guest_msr_reads);
run_in_new_process(&verify_guest_hlt);
+ run_in_new_process(&verify_mmio_reads);

return 0;
}
--
2.39.0.246.g2a6d74b583-goog