[dpdk-dev] [PATCH v4 02/44] bus/vdev: add driver IOVA VA mode requirement

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch adds driver flag in vdev bus driver so that
vdev drivers can require VA IOVA mode to be used, which
for example the case of Virtio-user PMD.

The patch implements the .get_iommu_class() callback, that
is called before devices probing to determine the IOVA mode
to be used, and adds a check right before the device is
probed to ensure compatible IOVA mode has been selected.

It also adds a ABI exception rule to accommodate with an
update on the driver registration API

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 devtools/libabigail.abignore    |  2 ++
 drivers/bus/vdev/rte_bus_vdev.h |  4 ++++
 drivers/bus/vdev/vdev.c         | 29 +++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/devtools/libabigail.abignore b/devtools/libabigail.abignore
index 1dc84fa74b..170304c876 100644
--- a/devtools/libabigail.abignore
+++ b/devtools/libabigail.abignore
@@ -11,6 +11,8 @@
 ; Explicit ignore for driver-only ABI
 [suppress_type]
         name = eth_dev_ops
+[suppress_function]
+        name_regexp = rte_vdev_(|un)register
 
 ; Ignore fields inserted in cacheline boundary of rte_cryptodev
 [suppress_type]
diff --git a/drivers/bus/vdev/rte_bus_vdev.h b/drivers/bus/vdev/rte_bus_vdev.h
index f99a41f825..fc315d10fa 100644
--- a/drivers/bus/vdev/rte_bus_vdev.h
+++ b/drivers/bus/vdev/rte_bus_vdev.h
@@ -113,8 +113,12 @@ struct rte_vdev_driver {
 	rte_vdev_remove_t *remove;       /**< Virtual device remove function. */
 	rte_vdev_dma_map_t *dma_map;     /**< Virtual device DMA map function. */
 	rte_vdev_dma_unmap_t *dma_unmap; /**< Virtual device DMA unmap function. */
+	uint32_t drv_flags;              /**< Flags RTE_VDEV_DRV_*. */
 };
 
+/** Device driver needs IOVA as VA and cannot work with IOVA as PA */
+#define RTE_VDEV_DRV_NEED_IOVA_AS_VA 0x0001
+
 /**
  * Register a virtual device driver.
  *
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index acfd78828f..9a673347ae 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -189,6 +189,7 @@ vdev_probe_all_drivers(struct rte_vdev_device *dev)
 {
 	const char *name;
 	struct rte_vdev_driver *driver;
+	enum rte_iova_mode iova_mode;
 	int ret;
 
 	if (rte_dev_is_probed(&dev->device))
@@ -199,6 +200,14 @@ vdev_probe_all_drivers(struct rte_vdev_device *dev)
 
 	if (vdev_parse(name, &driver))
 		return -1;
+
+	iova_mode = rte_eal_iova_mode();
+	if ((driver->drv_flags & RTE_VDEV_DRV_NEED_IOVA_AS_VA) && (iova_mode == RTE_IOVA_PA)) {
+		VDEV_LOG(ERR, "%s requires VA IOVA mode but current mode is PA, not initializing",
+				name);
+		return -1;
+	}
+
 	ret = driver->probe(dev);
 	if (ret == 0)
 		dev->device.driver = &driver->driver;
@@ -594,6 +603,25 @@ vdev_unplug(struct rte_device *dev)
 	return rte_vdev_uninit(dev->name);
 }
 
+static enum rte_iova_mode
+vdev_get_iommu_class(void)
+{
+	const char *name;
+	struct rte_vdev_device *dev;
+	struct rte_vdev_driver *driver;
+
+	TAILQ_FOREACH(dev, &vdev_device_list, next) {
+		name = rte_vdev_device_name(dev);
+		if (vdev_parse(name, &driver))
+			continue;
+
+		if (driver->drv_flags & RTE_VDEV_DRV_NEED_IOVA_AS_VA)
+			return RTE_IOVA_VA;
+	}
+
+	return RTE_IOVA_DC;
+}
+
 static struct rte_bus rte_vdev_bus = {
 	.scan = vdev_scan,
 	.probe = vdev_probe,
@@ -603,6 +631,7 @@ static struct rte_bus rte_vdev_bus = {
 	.parse = vdev_parse,
 	.dma_map = vdev_dma_map,
 	.dma_unmap = vdev_dma_unmap,
+	.get_iommu_class = vdev_get_iommu_class,
 	.dev_iterate = rte_vdev_dev_iterate,
 };
 
-- 
2.29.2