net/virtio: fix MSI-X for modern devices

The field, use_msix, in struct virtio_hw is not updated for modern
device, and is always zero. And now we depend on the status feature
and MSI-X to report LSC support (which is also not a correct
behavior). As a result, LSC is always disabled for modern devices.

To fix this, we just recognize MSI-X capability when going through
capability list, and update the info in virtio.

Fixes: 6ba1f63b5ab0 ("virtio: support specification 1.0")
Cc: stable@dpdk.org
Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index b767c03..ecad46e 100644 (file)
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -50,6 +50,7 @@
  */
 #define PCI_CAPABILITY_LIST    0x34
 #define PCI_CAP_ID_VNDR                0x09
+#define PCI_CAP_ID_MSIX                0x11
 
 /*
  * The remaining space is defined by each driver as the per-driver
@@ -650,6 +651,9 @@ 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_VNDR) {
                        PMD_INIT_LOG(DEBUG,
                                "[%2x] skipping non VNDR cap id: %02x",