X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=drivers%2Fnet%2Fvirtio%2Fvirtio_pci.c;h=f91ecb4c873d6cc54d6b5283391bd41f1b186fa3;hb=7555c20f2c2df8dbcf648e97a7005966048a0353;hp=b7b3d61575649ea9088fe7880d081ca0892f40bb;hpb=76f89ef557ff345dfa606e797e1765404babce56;p=deb_dpdk.git

diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index b7b3d615..f91ecb4c 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -579,6 +579,8 @@ get_cfg_addr(struct rte_pci_device *dev, struct virtio_pci_cap *cap)
 	return base + offset;
 }
 
+#define PCI_MSIX_ENABLE 0x8000
+
 static int
 virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
 {
@@ -605,8 +607,17 @@ virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
 			break;
 		}
 
-		if (cap.cap_vndr == PCI_CAP_ID_MSIX)
-			hw->use_msix = 1;
+		if (cap.cap_vndr == PCI_CAP_ID_MSIX) {
+			/* Transitional devices would also have this capability,
+			 * that's why we also check if msix is enabled.
+			 * 1st byte is cap ID; 2nd byte is the position of next
+			 * cap; next two bytes are the flags.
+			 */
+			uint16_t flags = ((uint16_t *)&cap)[1];
+
+			if (flags & PCI_MSIX_ENABLE)
+				hw->use_msix = 1;
+		}
 
 		if (cap.cap_vndr != PCI_CAP_ID_VNDR) {
 			PMD_INIT_LOG(DEBUG,