path: root/drivers/net/virtio/virtio_pci.c
diff options
authorJianfeng Tan <>2017-07-28 23:01:14 +0000
committerThomas Monjalon <>2017-07-31 18:45:59 +0200
commitcb482cb3a305f96d8155bbeb052344dde66ad8f2 (patch)
treede3aeea2357de3ddd4263abcaae8a380504010c8 /drivers/net/virtio/virtio_pci.c
parentc0bad56ef8b84a2e03bff1f5739a52248d22aedd (diff)
net/virtio: fix MAC address read
When virtio-net devices are bound to uio_pci_generic, we get the wrong mac addr by virtio PMD. The wrong mac addr is a addr that is 4-byte left shift of the correct addr. It's a regression bug introduced by the cleanup patch below. The condition of if we set use_msix should be if msix is actually enabled. Only to check if there is a capability list is not enough. For example, binding a transitional device to uio_pci_device would trigger the wrong assignment of use_msix. To correct that, we also check the flags of msix capability to make sure it's enabled. Fixes: ee1843bd8907 ("net/virtio: remove redundant MSI-X detection") Cc: Reported-by: Vipin Varghese <> Signed-off-by: Jianfeng Tan <> Acked-by: Yuanhan Liu <>
Diffstat (limited to 'drivers/net/virtio/virtio_pci.c')
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
index e6eda75..e6da680 100644
--- a/drivers/net/virtio/virtio_pci.c
+++ b/drivers/net/virtio/virtio_pci.c
@@ -580,6 +580,8 @@ 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)
@@ -606,8 +608,17 @@ virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
- 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) {