Hi Fabiano,
On 2025/12/13 02:10, Fabiano Rosas wrote:
Tao Tang <[email protected]> writes:
Add a qtest suite that validates ARM SMMUv3 translation without guest
firmware or OS. The tests leverage iommu-testdev to trigger DMA
operations and the qos-smmuv3 library to configure IOMMU translation
structures.
This test suite targets the virt machine and covers:
- Stage 1 only translation (VA -> PA via CD page tables)
- Stage 2 only translation (IPA -> PA via STE S2 tables)
- Nested translation (VA -> IPA -> PA, Stage 1 + Stage 2)
- Design to extended to support multiple security spaces
(Non-Secure, Secure, Root, Realm)
Each test case follows this sequence:
1. Initialize SMMUv3 with appropriate command/event queues
2. Build translation tables (STE/CD/PTE) for the target scenario
3. Configure iommu-testdev with IOVA and DMA attributes via MMIO
4. Trigger DMA and validate successful translation
5. Verify data integrity through a deterministic write-read pattern
This bare-metal approach provides deterministic IOMMU testing with
minimal dependencies, making failures directly attributable to the SMMU
translation path.
Signed-off-by: Tao Tang <[email protected]>
Tested-by: Pierrick Bouvier <[email protected]>
Reviewed-by: Pierrick Bouvier <[email protected]>
---
tests/qtest/iommu-smmuv3-test.c | 131 ++++++++++++++++++++++++++++++++
tests/qtest/meson.build | 1 +
2 files changed, 132 insertions(+)
create mode 100644 tests/qtest/iommu-smmuv3-test.c
diff --git a/tests/qtest/iommu-smmuv3-test.c b/tests/qtest/iommu-smmuv3-test.c
new file mode 100644
index 0000000000..96f66ee325
--- /dev/null
+++ b/tests/qtest/iommu-smmuv3-test.c
@@ -0,0 +1,131 @@
+/*
+ * QTest for SMMUv3 with iommu-testdev
+ *
+ * This QTest file is used to test the SMMUv3 with iommu-testdev so that we can
+ * test SMMUv3 without any guest kernel or firmware.
+ *
+ * Copyright (c) 2025 Phytium Technology
+ *
+ * Author:
+ * Tao Tang <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "libqtest.h"
+#include "libqos/pci.h"
+#include "libqos/generic-pcihost.h"
+#include "hw/pci/pci_regs.h"
+#include "hw/misc/iommu-testdev.h"
+#include "libqos/qos-smmuv3.h"
+
+#define DMA_LEN 4
+
+static QPCIDevice *setup_qtest_pci_device(QTestState *qts, QGenericPCIBus
*gbus,
+ QPCIBar *bar)
+{
+ uint16_t vid, did;
+ QPCIDevice *dev = NULL;
+
+ qpci_init_generic(gbus, qts, NULL, false);
+
+ /* Find device by vendor/device ID to avoid slot surprises. */
+ for (int s = 0; s < 32 && !dev; s++) {
+ for (int fn = 0; fn < 8 && !dev; fn++) {
+ QPCIDevice *cand = qpci_device_find(&gbus->bus, QPCI_DEVFN(s, fn));
+ if (!cand) {
+ continue;
+ }
+ vid = qpci_config_readw(cand, PCI_VENDOR_ID);
+ did = qpci_config_readw(cand, PCI_DEVICE_ID);
+ if (vid == IOMMU_TESTDEV_VENDOR_ID &&
+ did == IOMMU_TESTDEV_DEVICE_ID) {
+ dev = cand;
+ g_test_message("Found iommu-testdev! devfn: 0x%x",
cand->devfn);
+ } else {
+ g_free(cand);
+ }
+ }
+ }
This loop could be replaced with something simpler:
static void save_fn(QPCIDevice *dev, int devfn, void *data)
{
QPCIDevice **pdev = (QPCIDevice **) data;
*pdev = dev;
}
qpci_device_foreach(&gbus->bus, IOMMU_TESTDEV_VENDOR_ID,
IOMMU_TESTDEV_DEVICE_ID, save_fn, &dev);
Thanks for the suggestion.
I looked into this pattern and it does seem to be the standard approach
in QEMU qtests (e.g. tests/qtest/ivshmem-test.c). I will update the code
accordingly in the next revision.
Regards,
Tao
