mbuf_tag memory freeing issues with LRO enabled on the XENHVM driver

[Egoitz Aurrekoetxea]

Good afternoon,

It seems the LRO code inside the FreeBSD's kernel is causing the first mbuf chain’s anymbuf->m_hdr->mh_flags due to some failure not to contain the M_PKTHDR  flag. 
Have you ever seen this bad behavior with any of these  drivers having LRO enabled : 

cxgb
cxgbe
e1000
ixgbe
ixgbe
mxge
oce
qlxgb
qlxge
virtio
vxge

The no presence of this flag, seems to be causing the kernel not to be able to enter : 

static void
mb_dtor_pack(void *mem, int size, void *arg)
{
	struct mbuf *m;

	m = (struct mbuf *)mem;
	if ((m->m_flags & M_PKTHDR) != 0)
		m_tag_delete_chain(m, NULL);              <============ to this function.

causing the wired memory to increase a lot due mbuf_tags usage memory to be pretty high.

I have noticed about this issue using the XENHVM network driver (xn), but taking a look at some other drivers using the same code as this one… have found the commented before ones….

Has anyone too suffered the issue?.

Best regards,