[3/4] tests/qtest: Add ivshmem-flat test

diff --git a/tests/qtest/ivshmem-flat-test.c b/tests/qtest/ivshmem-flat-test.c
new file mode 100644
index 0000000000..7a4547637c
--- /dev/null
+++ b/tests/qtest/ivshmem-flat-test.c
@@ -0,0 +1,319 @@ 
+/*
+ * Inter-VM Shared Memory Flat Device qtests
+ *
+ * SPDX-FileCopyrightText: 2023 Linaro Ltd.
+ * SPDX-FileContributor: Gustavo Romero <gustavo.romero@linaro.org>
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ */
+
+#include "ivshmem-utils.h"
+
+#define IVSHMEM_FLAT_MMR_ADDR 0x400FF000
+#define IVSHMEM_FLAT_SHM_ADDR 0x40100000
+#define SHM_SIZE 131072 /* 128k */
+
+static ServerThread thread;
+
+uint32_t *shm_ptr;
+char *shm_rel_path;
+char *server_socket_path;
+
+static void cleanup(void)
+{
+    if (shm_ptr) {
+        munmap(shm_ptr, SHM_SIZE);
+        shm_ptr = NULL;
+    }
+
+    if (shm_rel_path) {
+        shm_unlink(shm_rel_path);
+        shm_rel_path = NULL;
+    }
+
+    if (server_socket_path) {
+        unlink(server_socket_path);
+        server_socket_path = NULL;
+    }
+}
+
+static void abort_handler(void *data)
+{
+    test_ivshmem_server_stop(&thread);
+    cleanup();
+}
+
+/*
+ * Check if exactly 1 positive pulse (low->high->low) on 'irq' IRQ line happens
+ * in 'timeout' second(s). 'irq' must be intercepted using qtest_irq_intercept_*
+ * before this function can be used on it. It returns 0 when pulse is detected,
+ * otherwise 1.
+ */
+static int test_ivshmem_flat_irq_positive_pulse(QTestState *qts, int irq,
+                                                int timeout)
+{
+    uint64_t num_raises = 0;
+    uint64_t num_lows = 0;
+    uint64_t end_time;
+
+    end_time = g_get_monotonic_time() + timeout * G_TIME_SPAN_SECOND;
+    do {
+        if ((num_raises = qtest_get_irq_raised_counter(qts, 0))) {
+            num_lows = qtest_get_irq_lowered_counter(qts, 0);
+            /* Check for 1 raise and 1 low IRQ event. */
+            if (num_raises == num_lows && num_lows == 1) {
+                return 0;
+            } else {
+                g_message("%s: Timeout expired", __func__);
+                return 1;
+            }
+        }
+        qtest_clock_step(qts, 10000);
+    } while (g_get_monotonic_time() < end_time);
+
+    return 1;
+}
+
+static inline uint32_t read_reg(QTestState *qts, enum Reg reg)
+{
+    uint32_t v;
+
+    qtest_memread(qts, IVSHMEM_FLAT_MMR_ADDR + reg, &v, sizeof(v));
+
+    return v;
+}
+
+static inline void write_reg(QTestState *qts, enum Reg reg, uint32_t v)
+{
+    qtest_memwrite(qts, IVSHMEM_FLAT_MMR_ADDR + reg, &v, sizeof(v));
+}
+
+/*
+ * Setup a test VM with ivshmem-flat device attached, IRQ properly set, and
+ * connected to the ivshmem-server.
+ */
+static QTestState *setup_vm(void)
+{
+    QTestState *qts;
+    const char *cmd_line;
+
+    cmd_line = g_strdup_printf("-machine lm3s6965evb "
+                               "-chardev socket,path=%s,id=ivshm "
+                               "-device ivshmem-flat,chardev=ivshm,"
+                               "x-irq-qompath='/machine/unattached/device[1]/nvic/unnamed-gpio-in[0]',"
+                               "x-bus-qompath='/sysbus',shmem-size=%d",
+                               server_socket_path, SHM_SIZE);
+    qts = qtest_init(cmd_line);
+
+    return qts;
+}
+
+static void test_ivshmem_flat_irq(void)
+{
+    QTestState *vm_state;
+    uint16_t own_id;
+
+    vm_state = setup_vm();
+
+    qtest_irq_intercept_out_named(vm_state,
+                                  "/machine/peripheral-anon/device[0]",
+                                  "irq-output");
+
+    /* IVPOSTION has the device's own ID distributed by the ivshmem-server. */
+    own_id = read_reg(vm_state, IVPOSITION);
+
+    /* Make device notify itself. */
+    write_reg(vm_state, DOORBELL, (own_id << 16) | 0 /* vector 0 */);
+
+    /*
+     * Check intercepted device's IRQ output line. Named IRQ line 'irq-output'
+     * was associated to qtest IRQ 0 and after self notification qtest IRQ 0
+     * must be toggled by the device. The test fails if no toggling is detected
+     * in 2 seconds.
+     */
+    g_assert(test_ivshmem_flat_irq_positive_pulse(vm_state, 0, 2) == 0);
+
+    qtest_quit(vm_state);
+}
+
+static void test_ivshmem_flat_shm_write(void)
+{
+    QTestState *vm_state;
+    int num_elements, i;
+    uint32_t  *data;
+
+    vm_state = setup_vm();
+
+    /* Prepare test data with random values. */
+    data = g_malloc(SHM_SIZE);
+    num_elements = SHM_SIZE/sizeof(*data);
+    for (i = 0; i < num_elements; i++) {
+        data[i] = g_test_rand_int();
+    }
+
+    /*
+     * Write test data to VM address IVSHMEM_FLAT_SHM_ADDR, where the shared
+     * memory region is located.
+     */
+    qtest_memwrite(vm_state, IVSHMEM_FLAT_SHM_ADDR, data, SHM_SIZE);
+
+    /*
+     * Since the shared memory fd is mmapped into this test process VMA at
+     * shm_ptr, every byte written by the VM in its shared memory region should
+     * also be available in the test process via shm_ptr. Thus, data in shm_ptr
+     * is compared back against the original test data.
+     */
+    for (i = 0; i < num_elements; i++) {
+        g_assert_cmpint(shm_ptr[i], ==, data[i]);
+    }
+
+    qtest_quit(vm_state);
+}
+
+static void test_ivshmem_flat_shm_read(void)
+{
+    QTestState *vm_state;
+    int num_elements, i;
+    uint32_t  *data;
+    uint32_t v;
+
+    vm_state = setup_vm();
+
+    /* Prepare test data with random values. */
+    data = g_malloc(SHM_SIZE);
+    num_elements = SHM_SIZE/sizeof(*data);
+    for (i = 0; i < num_elements; i++) {
+        data[i] = g_test_rand_int();
+    }
+
+    /*
+     * Copy test data to the shared memory region so it can be read from the VM
+     * (IVSHMEM_FLAT_SHM_ADDR location).
+     */
+    memcpy(shm_ptr, data, SHM_SIZE);
+
+    /* Check data */
+    for (i = 0; i < num_elements; i++) {
+        qtest_memread(vm_state, IVSHMEM_FLAT_SHM_ADDR + i * sizeof(v), &v,
+                      sizeof(v));
+        g_assert_cmpint(v, ==, data[i]);
+    }
+
+    qtest_quit(vm_state);
+}
+
+static void test_ivshmem_flat_shm_pair(void)
+{
+    QTestState *vm0_state, *vm1_state;
+    uint16_t vm0_peer_id, vm1_peer_id;
+    int num_elements, i;
+    uint32_t  *data;
+    uint32_t v;
+
+    vm0_state = setup_vm();
+    vm1_state = setup_vm();
+
+    /* Get peer ID for the VM so it can be used for one notify each other. */
+    vm0_peer_id = read_reg(vm0_state, IVPOSITION);
+    vm1_peer_id = read_reg(vm1_state, IVPOSITION);
+
+    /* Observe vm1 IRQ output line first. */
+    qtest_irq_intercept_out_named(vm1_state,
+                                  "/machine/peripheral-anon/device[0]",
+                                  "irq-output");
+
+    /* Notify (interrupt) VM1 from VM0. */
+    write_reg(vm0_state, DOORBELL, (vm1_peer_id << 16) | 0 /* vector 0 */);
+
+    /* Check if VM1 IRQ output line is toggled after notification from VM0. */
+    g_assert(test_ivshmem_flat_irq_positive_pulse(vm1_state, 0, 2) == 0);
+
+    /* Secondly, observe VM0 IRQ output line first. */
+    qtest_irq_intercept_out_named(vm0_state,
+                                  "/machine/peripheral-anon/device[0]",
+                                  "irq-output");
+
+    /* ... and do the opposite: notify (interrupt) VM0 from VM1. */
+    write_reg(vm1_state, DOORBELL, (vm0_peer_id << 16) | 0 /* vector 0 */);
+
+    /* Check if VM0 IRQ output line is toggled after notification from VM0. */
+    g_assert(test_ivshmem_flat_irq_positive_pulse(vm0_state, 0, 2) == 0);
+
+    /* Prepare test data with random values. */
+    data = g_malloc(SHM_SIZE);
+    num_elements = SHM_SIZE/sizeof(*data);
+    for (i = 0; i < num_elements; i++) {
+        data[i] = g_test_rand_int();
+    }
+
+    /* Write test data on VM0. */
+    qtest_memwrite(vm0_state, IVSHMEM_FLAT_SHM_ADDR, data, SHM_SIZE);
+
+    /* Check test data on VM1. */
+    for (i = 0; i < num_elements; i++) {
+        qtest_memread(vm1_state, IVSHMEM_FLAT_SHM_ADDR + i * sizeof(v), &v,
+                      sizeof(v));
+        g_assert_cmpint(v, ==, data[i]);
+    }
+
+    /* Prepare new test data with random values. */
+    for (i = 0; i < num_elements; i++) {
+        data[i] = g_test_rand_int();
+    }
+
+    /* Write test data on VM1. */
+    qtest_memwrite(vm1_state, IVSHMEM_FLAT_SHM_ADDR, data, SHM_SIZE);
+
+    /* Check test data on VM0. */
+    for (i = 0; i < num_elements; i++) {
+        qtest_memread(vm0_state, IVSHMEM_FLAT_SHM_ADDR + i * sizeof(v), &v,
+                      sizeof(v));
+        g_assert_cmpint(v, ==, data[i]);
+    }
+
+    qtest_quit(vm0_state);
+    qtest_quit(vm1_state);
+}
+
+int main(int argc, char *argv[])
+{
+    int shm_fd, r;
+
+    g_test_init(&argc, &argv, NULL);
+
+    /* If test fails, stop server, cleanup socket and shm files. */
+    qtest_add_abrt_handler(abort_handler, NULL);
+
+    shm_rel_path = mktempshm(SHM_SIZE, &shm_fd);
+    g_assert(shm_rel_path);
+
+    /*
+     * Map shm to this test's VMA so it's possible to read/write from/to it. For
+     * VMs with the ivhsmem-flat device attached, this region will also be
+     * mapped in their own memory layout, at IVSHMEM_FLAT_SHM_ADDR (default).
+     */
+    shm_ptr = mmap(0, SHM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
+    g_assert(shm_ptr != MAP_FAILED);
+
+    server_socket_path = mktempsocket();
+    /* It never fails, so no assert(). */
+
+    /*
+     * Currently, ivshmem-flat device only supports notification via 1 vector,
+     * i.e. vector 0.
+     */
+    test_ivshmem_server_start(&thread, server_socket_path, shm_rel_path, 1);
+
+    /* Register tests. */
+    qtest_add_func("/ivshmem-flat/irq", test_ivshmem_flat_irq);
+    qtest_add_func("/ivshmem-flat/shm-write", test_ivshmem_flat_shm_write);
+    qtest_add_func("/ivshmem-flat/shm-read", test_ivshmem_flat_shm_read);
+    qtest_add_func("/ivshmem-flat/pair", test_ivshmem_flat_shm_pair);
+
+    r = g_test_run();
+
+    test_ivshmem_server_stop(&thread);
+    cleanup();
+
+    return r;
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index b6c4ca937c..e7475c7e23 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -195,6 +195,7 @@  qtests_aspeed = \
    'aspeed_smc-test',
    'aspeed_gpio-test']
 qtests_arm = \
+  (config_all_devices.has_key('CONFIG_IVSHMEM_FLAT_DEVICE') ? ['ivshmem-flat-test'] : []) + \
   (config_all_devices.has_key('CONFIG_MPS2') ? ['sse-timer-test'] : []) + \
   (config_all_devices.has_key('CONFIG_CMSDK_APB_DUALTIMER') ? ['cmsdk-apb-dualtimer-test'] : []) + \
   (config_all_devices.has_key('CONFIG_CMSDK_APB_TIMER') ? ['cmsdk-apb-timer-test'] : []) + \
@@ -306,6 +307,7 @@  qtests = {
   'dbus-vmstate-test': files('migration-helpers.c') + dbus_vmstate1,
   'erst-test': files('erst-test.c'),
   'ivshmem-test': ['ivshmem-utils.c', '../../contrib/ivshmem-server/ivshmem-server.c'],
+  'ivshmem-flat-test': ['ivshmem-utils.c', '../../contrib/ivshmem-server/ivshmem-server.c'],
   'migration-test': migration_files,
   'pxe-test': files('boot-sector.c'),
   'qos-test': [chardev, io, qos_test_ss.apply(config_host, strict: false).sources()],