tests/qtest/libqos: add qvirtqueue_reset_pool() for descriptor pool reset
Add a function to reset the virtqueue descriptor pool state without reinitializing the device. This is useful for tests that issue a high number of requests and are limited by the simplified virtio test driver's descriptor tracking, which decrements num_free but never increments it back. The function is safe for synchronous test code where requests are sent and completed before the next request is issued. Acked-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/qemu-devel/96cf23eea1204b34443218fe76bd4a5eaf9163e8.1779126034.git.qemu_oss@crudebyte.com Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Christian Schoenebeck committed
May 18, 2026 at 19:36 UTC
be33c56898f8b18617cff91525f0b68abee8de07
2 files changed
+25
tests/qtest/libqos/virtio.c
+23
@@ -464,6 +464,29 @@ bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx,
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return true;
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}
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+/*
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+ * qvirtqueue_reset_pool:
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+ * @vq: The virtqueue to reset
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+ *
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+ * Reset the descriptor pool state without reinitializing the device.
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+ * This is useful for tests that issue a high number of requests and
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+ * are limited by the simplified virtio test driver's descriptor tracking,
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+ * which decrements num_free but never increments it back.
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+ *
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+ * This is only safe for synchronous test code where requests are
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+ * sent and completed before the next request is issued. Do not use
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+ * with asynchronous code where multiple requests may be in-flight.
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+ *
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+ * Note: This only resets the available descriptor pool (free_head,
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+ * num_free). The used ring position (last_used_idx) is NOT reset
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+ * and should continue to track consumed responses across iterations.
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+ */
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+void qvirtqueue_reset_pool(QVirtQueue *vq)
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+{
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+ vq->free_head = 0;
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+ vq->num_free = vq->size;
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+}
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+
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void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx)
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{
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g_assert(vq->event);
tests/qtest/libqos/virtio.h
+2
@@ -150,6 +150,8 @@ void qvirtqueue_kick(QTestState *qts, QVirtioDevice *d, QVirtQueue *vq,
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bool qvirtqueue_get_buf(QTestState *qts, QVirtQueue *vq, uint32_t *desc_idx,
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uint32_t *len);
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+void qvirtqueue_reset_pool(QVirtQueue *vq);
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+
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void qvirtqueue_set_used_event(QTestState *qts, QVirtQueue *vq, uint16_t idx);
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void qvirtio_start_device(QVirtioDevice *vdev);