Add the framework to test the intel-iommu device.

Currently only tested cap/ecap bits correctness in scalable
modern mode. Also tested cap/ecap bits consistency before
and after system reset.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Clément Mathieu--Drif<clement.mathieu--drif@eviden.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 MAINTAINERS                    |  1 +
 include/hw/i386/intel_iommu.h  |  1 +
 tests/qtest/intel-iommu-test.c | 65 ++++++++++++++++++++++++++++++++++
 tests/qtest/meson.build        |  1 +
 4 files changed, 68 insertions(+)
 create mode 100644 tests/qtest/intel-iommu-test.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 095420f8b0..de3da859cf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3667,6 +3667,7 @@ S: Supported
 F: hw/i386/intel_iommu.c
 F: hw/i386/intel_iommu_internal.h
 F: include/hw/i386/intel_iommu.h
+F: tests/qtest/intel-iommu-test.c
 
 AMD-Vi Emulation
 S: Orphan
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index fa787d5b0d..1a4a53053f 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -47,6 +47,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(IntelIOMMUState, INTEL_IOMMU_DEVICE)
 #define VTD_HOST_AW_48BIT           48
 #define VTD_HOST_ADDRESS_WIDTH      VTD_HOST_AW_48BIT
 #define VTD_HAW_MASK(aw)            ((1ULL << (aw)) - 1)
+#define VTD_MGAW_FROM_CAP(cap)      ((cap >> 16) & 0x3fULL)
 
 #define DMAR_REPORT_F_INTR          (1)
 
diff --git a/tests/qtest/intel-iommu-test.c b/tests/qtest/intel-iommu-test.c
new file mode 100644
index 0000000000..82f5b6efcf
--- /dev/null
+++ b/tests/qtest/intel-iommu-test.c
@@ -0,0 +1,65 @@
+/*
+ * QTest testcase for intel-iommu
+ *
+ * Copyright (c) 2024 Intel, Inc.
+ *
+ * Author: Zhenzhong Duan <zhenzhong.duan@intel.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "libqtest.h"
+#include "hw/i386/intel_iommu_internal.h"
+
+#define CAP_MODERN_FIXED1    (VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND | \
+                              VTD_CAP_MAMV | VTD_CAP_PSI | VTD_CAP_SLLPS)
+#define ECAP_MODERN_FIXED1   (VTD_ECAP_QI |  VTD_ECAP_IR | VTD_ECAP_IRO | \
+                              VTD_ECAP_MHMV | VTD_ECAP_SMTS | VTD_ECAP_FLTS)
+
+static inline uint64_t vtd_reg_readq(QTestState *s, uint64_t offset)
+{
+    return qtest_readq(s, Q35_HOST_BRIDGE_IOMMU_ADDR + offset);
+}
+
+static void test_intel_iommu_modern(void)
+{
+    uint8_t init_csr[DMAR_REG_SIZE];     /* register values */
+    uint8_t post_reset_csr[DMAR_REG_SIZE];     /* register values */
+    uint64_t cap, ecap, tmp;
+    QTestState *s;
+
+    s = qtest_init("-M q35 -device intel-iommu,x-scalable-mode=on,x-flts=on");
+
+    cap = vtd_reg_readq(s, DMAR_CAP_REG);
+    g_assert((cap & CAP_MODERN_FIXED1) == CAP_MODERN_FIXED1);
+
+    tmp = cap & VTD_CAP_SAGAW_MASK;
+    g_assert(tmp == (VTD_CAP_SAGAW_39bit | VTD_CAP_SAGAW_48bit));
+
+    tmp = VTD_MGAW_FROM_CAP(cap);
+    g_assert(tmp == VTD_HOST_AW_48BIT - 1);
+
+    ecap = vtd_reg_readq(s, DMAR_ECAP_REG);
+    g_assert((ecap & ECAP_MODERN_FIXED1) == ECAP_MODERN_FIXED1);
+
+    qtest_memread(s, Q35_HOST_BRIDGE_IOMMU_ADDR, init_csr, DMAR_REG_SIZE);
+
+    qobject_unref(qtest_qmp(s, "{ 'execute': 'system_reset' }"));
+    qtest_qmp_eventwait(s, "RESET");
+
+    qtest_memread(s, Q35_HOST_BRIDGE_IOMMU_ADDR, post_reset_csr, DMAR_REG_SIZE);
+    /* Ensure registers are consistent after hard reset */
+    g_assert(!memcmp(init_csr, post_reset_csr, DMAR_REG_SIZE));
+
+    qtest_quit(s);
+}
+
+int main(int argc, char **argv)
+{
+    g_test_init(&argc, &argv, NULL);
+    qtest_add_func("/q35/intel-iommu/modern", test_intel_iommu_modern);
+
+    return g_test_run();
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index aa93e98418..83d5474f53 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -93,6 +93,7 @@ qtests_i386 = \
   (config_all_devices.has_key('CONFIG_SB16') ? ['fuzz-sb16-test'] : []) +                   \
   (config_all_devices.has_key('CONFIG_SDHCI_PCI') ? ['fuzz-sdcard-test'] : []) +            \
   (config_all_devices.has_key('CONFIG_ESP_PCI') ? ['am53c974-test'] : []) +                 \
+  (config_all_devices.has_key('CONFIG_VTD') ? ['intel-iommu-test'] : []) +                 \
   (host_os != 'windows' and                                                                \
    config_all_devices.has_key('CONFIG_ACPI_ERST') ? ['erst-test'] : []) +                   \
   (config_all_devices.has_key('CONFIG_PCIE_PORT') and                                       \
-- 
2.34.1