Crash on Hyper-V on a Linux with a generic network adapter

[bvital1976]

Hello
I am trying to run my program on a Centos 3.10-957.12.2.el7.x86_64 running in a Hyper-V virtual machine with a generic network adapter.
At first netmap did not want to start until I changed .objmaxsize from 32PAGE_SIZE to 64PAGE_SIZE and increased ring_size to 160000.
"pkt-gen -tx ..." started working.
Now netmap crashes at:

1249│ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
1250│ gfp_t gfp_mask)
1251│ {
1252│ int i;
1253│ u8 data;
1254│ int size = nhead + skb_end_offset(skb) + ntail;
1255│ long off;
1256│
1257│ BUG_ON(nhead < 0);
1258│
1259│ if (skb_shared(skb))
1260├> BUG();
1261│
1262│ size = SKB_DATA_ALIGN(size);
1263│
1264│ if (skb_pfmemalloc(skb))
1265│ gfp_mask |= __GFP_MEMALLOC;
1266│ data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
1267│ gfp_mask, NUMA_NO_NODE, NULL);
1268│ if (!data)
1269│ goto nodata;
1270│ size = SKB_WITH_OVERHEAD(ksize(data));
1271│
1272│ / Copy only real data... and, alas, header. This should be
1273│ * optimized for the cases when header is void.
1274│ */
1275│ memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head);
1276│-----------------------------------

The full stack trace is:
Thread 326 received signal SIGILL, Illegal instruction.
[Switching to Thread 5449]
pskb_expand_head (skb=0xffff88007cd0ea00, nhead=3776, ntail=, gfp_mask=32) at net/core/skbuff.c:1260
(gdb) bt
#0 pskb_expand_head (skb=0xffff88007cd0ea00, nhead=3776, ntail=, gfp_mask=32) at net/core/skbuff.c:1260
#1 0xffffffffc00cd7ba in ?? ()
#2 0xffff88005e0076a0 in ?? ()
#3 0xffffffff810e1438 in wakeup_preempt_entity (curr=0xffff88007cd0ea00, se=0xffff880035ed3000) at kernel/sched/fair.c:4739
#4 check_preempt_wakeup (rq=0x36 <irq_stack_union+54>, p=, wake_flags=) at kernel/sched/fair.c:4826
#5 0xffffffffc035bd04 in generic_ndo_start_xmit (m=0xffff88007cd0ea00, ifp=0xffff8800f2b45000) at /root/projects/netmap/LINUX/netmap_linux.c:647
#6 0xffffffff81639ce6 in __netdev_start_xmit (ops=, more=, dev=, skb=0xffff88007cd0ea00) at include/linux/netdevice.h:4121
#7 netdev_start_xmit (more=, txq=, dev=, skb=0xffff88007cd0ea00) at include/linux/netdevice.h:4130
#8 xmit_one (more=, txq=, dev=, skb=0xffff88007cd0ea00) at net/core/dev.c:3011
#9 dev_hard_start_xmit (first=first@entry=0xffff88007cd0ea00, dev=dev@entry=0xffff8800f2b45000, txq=txq@entry=0xffff8800359b83c0, ret=ret@entry=0xffff88005e00796c) at net/core/dev.c:3027
#10 0xffffffff81666d6a in sch_direct_xmit (skb=skb@entry=0xffff88007cd0ea00, q=q@entry=0xffff880036955e00, dev=0xffff8800f2b45000, txq=0xffff8800359b83c0, root_lock=root_lock@entry=0xffff880036955e9c, validate=validate@entry=true) at net/sched/sch_generic.c:217
#11 0xffffffff81666f2e in qdisc_restart (packets=, q=0xffff880036955e00) at net/sched/sch_generic.c:283
#12 __qdisc_run (q=q@entry=0xffff880036955e00) at net/sched/sch_generic.c:291
#13 0xffffffff8163c9e8 in __dev_xmit_skb (txq=0xffff8800359b83c0, dev=, q=0xffff880036955e00, skb=0xffff88007cd0ea00) at net/core/dev.c:3225
#14 __dev_queue_xmit (skb=skb@entry=0xffff88007cd0ea00, accel_priv=accel_priv@entry=0x0 <irq_stack_union>) at net/core/dev.c:3456
#15 0xffffffff8163ce30 in dev_queue_xmit (skb=skb@entry=0xffff88007cd0ea00) at net/core/dev.c:3521
#16 0xffffffffc035dc56 in nm_os_generic_xmit_frame (a=a@entry=0xffff88005e007b78) at /root/projects/netmap/LINUX/netmap_linux.c:1048
#17 0xffffffffc034ee4f in generic_netmap_txsync (kring=0xffff8800d4f92650, flags=6) at /root/projects/netmap/LINUX/../sys/dev/netmap/netmap_generic.c:737
#18 0xffffffffc035949d in netmap_ioctl (priv=priv@entry=0xffff8800f09ec8a0, cmd=cmd@entry=27028, data=data@entry=0xffff88005e007d58 "5\307\305;1\026\320X\f\201\377\377\377\377\340Y\311\a\001\210\377\377\310}", td=td@entry=0x0 <irq_stack_union>, nr_body_is_user=nr_body_is_user@entry=1) at /root/projects/netmap/LINUX/../sys/dev/netmap/netmap.c:3144
#19 0xffffffffc035bfa5 in linux_netmap_ioctl (file=0xffff88007d057200, cmd=27028, data=0) at /root/projects/netmap/LINUX/netmap_linux.c:1431
#20 0xffffffff81256950 in vfs_ioctl (arg=, cmd=, filp=) at fs/ioctl.c:43
#21 do_vfs_ioctl (filp=filp@entry=0xffff88007d057200, fd=fd@entry=8, cmd=cmd@entry=27028, arg=arg@entry=0) at fs/ioctl.c:631
#22 0xffffffff81256bf1 in SYSC_ioctl (arg=0, cmd=27028, fd=8) at fs/ioctl.c:646
#23 SyS_ioctl (fd=8, cmd=27028, arg=0) at fs/ioctl.c:637
#24
#25 0x00007fb4c75c6307 in ?? ()