[dpdk-dev] [PATCH v4] net/virtio: fix rxq intr config fails using vfio-pci

Zhiyong Yang zhiyong.yang at intel.com
Thu Nov 9 05:46:07 CET 2017


When running l3fwd-power to test virtio rxq interrupt using vfio
pci noiommu mode, startup fails. In the function virtio_read_caps,
the code if (flags & PCI_MSIX_ENABLE) intends to double check
if vfio msix is enabled or not. However, it is not enable at that
time. So use_msix is assigned to "0", not "1", which causes the
failure of configuring rxq intr in l3fwd-power.
This patch adds the function "vtpci_msix_detect" to detect the status
of msix when interrupt changes happen.
In the meanwhile, virtio_intr_enable/disable are introduced to wrap
rte_intr_enable/disable to enhance the ability to detect msix.
use_msix can indicate three different msix status by:
VIRTIO_MSIX_NONE (0)
VIRTIO_MSIX_DISABLED (1)
VIRTIO_MSIX_ENABLED (2)

CC: stable at dpdk.org
CC: jianfeng.tan at intel.com
CC: yliu at fridaylinux.org
CC: maxime.coquelin at redhat.com

Fixes: cb482cb3a305 ("net/virtio: fix MAC address read")
Signed-off-by: Zhiyong Yang <zhiyong.yang at intel.com>
---

Changes in v4:
Enhance the commit log description.

Changes in v3:
Simply the code according to jianfeng's comments.

Changes in v2:
Add the capability to detect msix if virtio intr changes.

 drivers/net/virtio/virtio_ethdev.c | 46 ++++++++++++++++++++++++++++++------
 drivers/net/virtio/virtio_pci.c    | 48 ++++++++++++++++++++++++++++++++++++--
 drivers/net/virtio/virtio_pci.h    |  6 +++++
 3 files changed, 91 insertions(+), 9 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index d2576d5e0..87ac2bee6 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -97,6 +97,9 @@ static void virtio_mac_addr_remove(struct rte_eth_dev *dev, uint32_t index);
 static void virtio_mac_addr_set(struct rte_eth_dev *dev,
 				struct ether_addr *mac_addr);
 
+static int virtio_intr_enable(struct rte_eth_dev *dev);
+static int virtio_intr_disable(struct rte_eth_dev *dev);
+
 static int virtio_dev_queue_stats_mapping_set(
 	struct rte_eth_dev *eth_dev,
 	uint16_t queue_id,
@@ -618,7 +621,7 @@ virtio_dev_close(struct rte_eth_dev *dev)
 		virtio_queues_unbind_intr(dev);
 
 	if (intr_conf->lsc || intr_conf->rxq) {
-		rte_intr_disable(dev->intr_handle);
+		virtio_intr_disable(dev);
 		rte_intr_efd_disable(dev->intr_handle);
 		rte_free(dev->intr_handle->intr_vec);
 		dev->intr_handle->intr_vec = NULL;
@@ -1160,6 +1163,34 @@ virtio_vlan_filter_set(struct rte_eth_dev *dev, uint16_t vlan_id, int on)
 }
 
 static int
+virtio_intr_enable(struct rte_eth_dev *dev)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+
+	if (rte_intr_enable(dev->intr_handle) < 0)
+		return -1;
+
+	if (!hw->virtio_user_dev)
+		hw->use_msix = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));
+
+	return 0;
+}
+
+static int
+virtio_intr_disable(struct rte_eth_dev *dev)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+
+	if (rte_intr_disable(dev->intr_handle) < 0)
+		return -1;
+
+	if (!hw->virtio_user_dev)
+		hw->use_msix = vtpci_msix_detect(RTE_ETH_DEV_TO_PCI(dev));
+
+	return 0;
+}
+
+static int
 virtio_negotiate_features(struct virtio_hw *hw, uint64_t req_features)
 {
 	uint64_t host_features;
@@ -1228,7 +1259,7 @@ virtio_interrupt_handler(void *param)
 	isr = vtpci_isr(hw);
 	PMD_DRV_LOG(INFO, "interrupt status = %#x", isr);
 
-	if (rte_intr_enable(dev->intr_handle) < 0)
+	if (virtio_intr_enable(dev) < 0)
 		PMD_DRV_LOG(ERR, "interrupt enable failed");
 
 	if (isr & VIRTIO_PCI_ISR_CONFIG) {
@@ -1348,7 +1379,7 @@ virtio_configure_intr(struct rte_eth_dev *dev)
 	 * to change the config size from 20 to 24, or VIRTIO_MSI_QUEUE_VECTOR
 	 * (22) will be ignored.
 	 */
-	if (rte_intr_enable(dev->intr_handle) < 0) {
+	if (virtio_intr_enable(dev) < 0) {
 		PMD_DRV_LOG(ERR, "interrupt enable failed");
 		return -1;
 	}
@@ -1388,7 +1419,8 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
 	}
 
 	/* If host does not support both status and MSI-X then disable LSC */
-	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) && hw->use_msix)
+	if (vtpci_with_feature(hw, VIRTIO_NET_F_STATUS) &&
+	    hw->use_msix != VIRTIO_MSIX_NONE)
 		eth_dev->data->dev_flags |= RTE_ETH_DEV_INTR_LSC;
 	else
 		eth_dev->data->dev_flags &= ~RTE_ETH_DEV_INTR_LSC;
@@ -1801,9 +1833,9 @@ virtio_dev_start(struct rte_eth_dev *dev)
 	 */
 	if (dev->data->dev_conf.intr_conf.lsc ||
 	    dev->data->dev_conf.intr_conf.rxq) {
-		rte_intr_disable(dev->intr_handle);
+		virtio_intr_disable(dev);
 
-		if (rte_intr_enable(dev->intr_handle) < 0) {
+		if (virtio_intr_enable(dev) < 0) {
 			PMD_DRV_LOG(ERR, "interrupt enable failed");
 			return -EIO;
 		}
@@ -1912,7 +1944,7 @@ virtio_dev_stop(struct rte_eth_dev *dev)
 	PMD_INIT_LOG(DEBUG, "stop");
 
 	if (intr_conf->lsc || intr_conf->rxq)
-		rte_intr_disable(dev->intr_handle);
+		virtio_intr_disable(dev);
 
 	hw->started = 0;
 	memset(&link, 0, sizeof(link));
diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index 55b717c03..10c45228c 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -57,7 +57,8 @@
  * The remaining space is defined by each driver as the per-driver
  * configuration space.
  */
-#define VIRTIO_PCI_CONFIG(hw) (((hw)->use_msix) ? 24 : 20)
+#define VIRTIO_PCI_CONFIG(hw) \
+		(((hw)->use_msix == VIRTIO_MSIX_ENABLED) ? 24 : 20)
 
 static inline int
 check_vq_phys_addr_ok(struct virtqueue *vq)
@@ -617,7 +618,9 @@ virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
 			uint16_t flags = ((uint16_t *)&cap)[1];
 
 			if (flags & PCI_MSIX_ENABLE)
-				hw->use_msix = 1;
+				hw->use_msix = VIRTIO_MSIX_ENABLED;
+			else
+				hw->use_msix = VIRTIO_MSIX_DISABLED;
 		}
 
 		if (cap.cap_vndr != PCI_CAP_ID_VNDR) {
@@ -710,3 +713,44 @@ vtpci_init(struct rte_pci_device *dev, struct virtio_hw *hw)
 
 	return 0;
 }
+
+/* Return 0 (VIRTIO_MSIX_NONE)
+ * Return 1 (VIRTIO_MSIX_DISABLED)
+ * Return 2 (VIRTIO_MSIX_ENABLED)
+ */
+
+uint8_t
+vtpci_msix_detect(struct rte_pci_device *dev)
+{
+	uint8_t pos;
+	struct virtio_pci_cap cap;
+	int ret;
+
+	ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST);
+	if (ret < 0) {
+		PMD_INIT_LOG(DEBUG, "failed to read pci capability list");
+		return VIRTIO_MSIX_NONE;
+	}
+
+	while (pos) {
+		ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos);
+		if (ret < 0) {
+			PMD_INIT_LOG(ERR,
+				"failed to read pci cap at pos: %x", pos);
+			break;
+		}
+
+		if (cap.cap_vndr == PCI_CAP_ID_MSIX) {
+			uint16_t flags = ((uint16_t *)&cap)[1];
+
+			if (flags & PCI_MSIX_ENABLE)
+				return VIRTIO_MSIX_ENABLED;
+			else
+				return VIRTIO_MSIX_DISABLED;
+		}
+
+		pos = cap.cap_next;
+	}
+
+	return VIRTIO_MSIX_NONE;
+}
diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
index 36d452c06..600e106eb 100644
--- a/drivers/net/virtio/virtio_pci.h
+++ b/drivers/net/virtio/virtio_pci.h
@@ -314,6 +314,10 @@ struct virtio_net_config {
 /* The alignment to use between consumer and producer parts of vring. */
 #define VIRTIO_PCI_VRING_ALIGN 4096
 
+#define VIRTIO_MSIX_NONE 0
+#define VIRTIO_MSIX_DISABLED 1
+#define VIRTIO_MSIX_ENABLED 2
+
 static inline int
 vtpci_with_feature(struct virtio_hw *hw, uint64_t bit)
 {
@@ -339,6 +343,8 @@ void vtpci_read_dev_config(struct virtio_hw *, size_t, void *, int);
 
 uint8_t vtpci_isr(struct virtio_hw *);
 
+uint8_t vtpci_msix_detect(struct rte_pci_device *dev);
+
 extern const struct virtio_pci_ops legacy_ops;
 extern const struct virtio_pci_ops modern_ops;
 extern const struct virtio_pci_ops virtio_user_ops;
-- 
2.13.3



More information about the dev mailing list