[PATCH v2 13/15] qtest/riscv-iommu-test: add init queues test

[Daniel Henrique Barboza]

Add an additional test to further exercise the IOMMU where we attempt to
initialize the command, fault and page-request queues.

These steps are taken from chapter 6.2 of the RISC-V IOMMU spec,
"Guidelines for initialization". It emulates what we expect from the
software/OS when initializing the IOMMU.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 tests/qtest/libqos/riscv-iommu.h |  29 +++++++
 tests/qtest/riscv-iommu-test.c   | 141 +++++++++++++++++++++++++++++++
 2 files changed, 170 insertions(+)

diff --git a/tests/qtest/libqos/riscv-iommu.h b/tests/qtest/libqos/riscv-iommu.h
index 8c056caa7b..aeaa5fb8b8 100644
--- a/tests/qtest/libqos/riscv-iommu.h
+++ b/tests/qtest/libqos/riscv-iommu.h
@@ -58,6 +58,35 @@
 
 #define RISCV_IOMMU_REG_IPSR            0x0054
 
+#define RISCV_IOMMU_REG_IVEC            0x02F8
+#define RISCV_IOMMU_REG_IVEC_CIV        GENMASK_ULL(3, 0)
+#define RISCV_IOMMU_REG_IVEC_FIV        GENMASK_ULL(7, 4)
+#define RISCV_IOMMU_REG_IVEC_PIV        GENMASK_ULL(15, 12)
+
+#define RISCV_IOMMU_REG_CQB             0x0018
+#define RISCV_IOMMU_CQB_PPN_START       10
+#define RISCV_IOMMU_CQB_PPN_LEN         44
+#define RISCV_IOMMU_CQB_LOG2SZ_START    0
+#define RISCV_IOMMU_CQB_LOG2SZ_LEN      5
+
+#define RISCV_IOMMU_REG_CQT             0x0024
+
+#define RISCV_IOMMU_REG_FQB             0x0028
+#define RISCV_IOMMU_FQB_PPN_START       10
+#define RISCV_IOMMU_FQB_PPN_LEN         44
+#define RISCV_IOMMU_FQB_LOG2SZ_START    0
+#define RISCV_IOMMU_FQB_LOG2SZ_LEN      5
+
+#define RISCV_IOMMU_REG_FQT             0x0034
+
+#define RISCV_IOMMU_REG_PQB             0x0038
+#define RISCV_IOMMU_PQB_PPN_START       10
+#define RISCV_IOMMU_PQB_PPN_LEN         44
+#define RISCV_IOMMU_PQB_LOG2SZ_START    0
+#define RISCV_IOMMU_PQB_LOG2SZ_LEN      5
+
+#define RISCV_IOMMU_REG_PQT             0x0044
+
 typedef struct QRISCVIOMMU {
     QOSGraphObject obj;
     QPCIDevice dev;
diff --git a/tests/qtest/riscv-iommu-test.c b/tests/qtest/riscv-iommu-test.c
index 13b887d15e..64f3f092f2 100644
--- a/tests/qtest/riscv-iommu-test.c
+++ b/tests/qtest/riscv-iommu-test.c
@@ -33,6 +33,20 @@ static uint64_t riscv_iommu_read_reg64(QRISCVIOMMU *r_iommu, 
int reg_offset)
     return reg;
 }
 
+static void riscv_iommu_write_reg32(QRISCVIOMMU *r_iommu, int reg_offset,
+                                    uint32_t val)
+{
+    qpci_memwrite(&r_iommu->dev, r_iommu->reg_bar, reg_offset,
+                  &val, sizeof(val));
+}
+
+static void riscv_iommu_write_reg64(QRISCVIOMMU *r_iommu, int reg_offset,
+                                    uint64_t val)
+{
+    qpci_memwrite(&r_iommu->dev, r_iommu->reg_bar, reg_offset,
+                  &val, sizeof(val));
+}
+
 static void test_pci_config(void *obj, void *data, QGuestAllocator *t_alloc)
 {
     QRISCVIOMMU *r_iommu = obj;
@@ -84,10 +98,137 @@ static void test_reg_reset(void *obj, void *data, 
QGuestAllocator *t_alloc)
     g_assert_cmpuint(reg, ==, 0);
 }
 
+/*
+ * Common timeout-based poll for CQCSR, FQCSR and PQCSR. All
+ * their ON bits are mapped as RISCV_IOMMU_QUEUE_ACTIVE (16),
+ */
+static void qtest_wait_for_queue_active(QRISCVIOMMU *r_iommu,
+                                        uint32_t queue_csr)
+{
+    QTestState *qts = global_qtest;
+    guint64 timeout_us = 2 * 1000 * 1000;
+    gint64 start_time = g_get_monotonic_time();
+    uint32_t reg;
+
+    for (;;) {
+        qtest_clock_step(qts, 100);
+
+        reg = riscv_iommu_read_reg32(r_iommu, queue_csr);
+        if (reg & RISCV_IOMMU_QUEUE_ACTIVE) {
+            break;
+        }
+        g_assert(g_get_monotonic_time() - start_time <= timeout_us);
+    }
+}
+
+/*
+ * Goes through the queue activation procedures of chapter 6.2,
+ * "Guidelines for initialization", of the RISCV-IOMMU spec.
+ */
+static void test_iommu_init_queues(void *obj, void *data,
+                                   QGuestAllocator *t_alloc)
+{
+    QRISCVIOMMU *r_iommu = obj;
+    uint64_t reg64, q_addr;
+    uint32_t reg;
+    int k;
+
+    reg64 = riscv_iommu_read_reg64(r_iommu, RISCV_IOMMU_REG_CAP);
+    g_assert_cmpuint(reg64 & RISCV_IOMMU_CAP_VERSION, ==, 0x10);
+
+    /*
+     * Program the command queue. Write 0xF to civ, assert that
+     * we have 4 writable bits (k = 4). The amount of entries N in the
+     * command queue is 2^4 = 16. We need to alloc a N*16 bytes
+     * buffer and use it to set cqb.
+     */
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_IVEC,
+                            0xFFFF & RISCV_IOMMU_REG_IVEC_CIV);
+    reg = riscv_iommu_read_reg32(r_iommu, RISCV_IOMMU_REG_IVEC);
+    g_assert_cmpuint(reg & RISCV_IOMMU_REG_IVEC_CIV, ==, 0xF);
+
+    q_addr = guest_alloc(t_alloc, 16 * 16);
+    reg64 = 0;
+    k = 4;
+    deposit64(reg64, RISCV_IOMMU_CQB_PPN_START,
+              RISCV_IOMMU_CQB_PPN_LEN, q_addr);
+    deposit64(reg64, RISCV_IOMMU_CQB_LOG2SZ_START,
+              RISCV_IOMMU_CQB_LOG2SZ_LEN, k - 1);
+    riscv_iommu_write_reg64(r_iommu, RISCV_IOMMU_REG_CQB, reg64);
+
+    /* cqt = 0, cqcsr.cqen = 1, poll cqcsr.cqon until it reads 1 */
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_CQT, 0);
+
+    reg = riscv_iommu_read_reg32(r_iommu, RISCV_IOMMU_REG_CQCSR);
+    reg |= RISCV_IOMMU_CQCSR_CQEN;
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_CQCSR, reg);
+
+    qtest_wait_for_queue_active(r_iommu, RISCV_IOMMU_REG_CQCSR);
+
+    /*
+     * Program the fault queue. Similar to the above:
+     * - Write 0xF to fiv, assert that we have 4 writable bits (k = 4)
+     * - Alloc a 16*32 bytes (instead of 16*16) buffer and use it to set
+     * fqb
+     */
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_IVEC,
+                            0xFFFF & RISCV_IOMMU_REG_IVEC_FIV);
+    reg = riscv_iommu_read_reg32(r_iommu, RISCV_IOMMU_REG_IVEC);
+    g_assert_cmpuint(reg & RISCV_IOMMU_REG_IVEC_FIV, ==, 0xF0);
+
+    q_addr = guest_alloc(t_alloc, 16 * 32);
+    reg64 = 0;
+    k = 4;
+    deposit64(reg64, RISCV_IOMMU_FQB_PPN_START,
+              RISCV_IOMMU_FQB_PPN_LEN, q_addr);
+    deposit64(reg64, RISCV_IOMMU_FQB_LOG2SZ_START,
+              RISCV_IOMMU_FQB_LOG2SZ_LEN, k - 1);
+    riscv_iommu_write_reg64(r_iommu, RISCV_IOMMU_REG_FQB, reg64);
+
+    /* fqt = 0, fqcsr.fqen = 1, poll fqcsr.fqon until it reads 1 */
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_FQT, 0);
+
+    reg = riscv_iommu_read_reg32(r_iommu, RISCV_IOMMU_REG_FQCSR);
+    reg |= RISCV_IOMMU_FQCSR_FQEN;
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_FQCSR, reg);
+
+    qtest_wait_for_queue_active(r_iommu, RISCV_IOMMU_REG_FQCSR);
+
+    /*
+     * Program the page-request queue:
+     - Write 0xF to piv, assert that we have 4 writable bits (k = 4)
+     - Alloc a 16*16 bytes buffer and use it to set pqb.
+     */
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_IVEC,
+                            0xFFFF & RISCV_IOMMU_REG_IVEC_PIV);
+    reg = riscv_iommu_read_reg32(r_iommu, RISCV_IOMMU_REG_IVEC);
+    g_assert_cmpuint(reg & RISCV_IOMMU_REG_IVEC_PIV, ==, 0xF000);
+
+    q_addr = guest_alloc(t_alloc, 16 * 16);
+    reg64 = 0;
+    k = 4;
+    deposit64(reg64, RISCV_IOMMU_PQB_PPN_START,
+              RISCV_IOMMU_PQB_PPN_LEN, q_addr);
+    deposit64(reg64, RISCV_IOMMU_PQB_LOG2SZ_START,
+              RISCV_IOMMU_PQB_LOG2SZ_LEN, k - 1);
+    riscv_iommu_write_reg64(r_iommu, RISCV_IOMMU_REG_PQB, reg64);
+
+    /* pqt = 0, pqcsr.pqen = 1, poll pqcsr.pqon until it reads 1 */
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_PQT, 0);
+
+    reg = riscv_iommu_read_reg32(r_iommu, RISCV_IOMMU_REG_PQCSR);
+    reg |= RISCV_IOMMU_PQCSR_PQEN;
+    riscv_iommu_write_reg32(r_iommu, RISCV_IOMMU_REG_PQCSR, reg);
+
+    qtest_wait_for_queue_active(r_iommu, RISCV_IOMMU_REG_PQCSR);
+}
+
 static void register_riscv_iommu_test(void)
 {
     qos_add_test("pci_config", "riscv-iommu-pci", test_pci_config, NULL);
     qos_add_test("reg_reset", "riscv-iommu-pci", test_reg_reset, NULL);
+    qos_add_test("iommu_init_queues", "riscv-iommu-pci",
+                 test_iommu_init_queues, NULL);
 }
 
 libqos_init(register_riscv_iommu_test);
-- 
2.43.2