PVH panics

[marcotte%panix.com@localhost (Brian Marcotte)]

I've been trying out PVH, but I'm getting a panics in some cases. These
also happen with PVHVM.

NetBSD is from this morning (May 4).
dom0 is Linux/Xen 4.11.2+
CPU is Xeon E5-2660

Thanks for all your work on this!

- Brian

-------------------
The first one happens just when starting rpcbind: 

    panic: kernel diagnostic assertion "IFNET_LOCKED(ifp)" failed: file "/devel/netbsd/current/src/sys/arch/xen/xen/if_xennet_xenbus.c", line 1272
    cpu1: Begin traceback...
    vpanic() at netbsd:vpanic+0x178
    kern_assert() at netbsd:kern_assert+0x48
    xennet_ioctl() at netbsd:xennet_ioctl+0x6d
    if_mcast_op() at netbsd:if_mcast_op+0x4b
    in6_addmulti() at netbsd:in6_addmulti+0x153
    in6_joingroup() at netbsd:in6_joingroup+0x45
    ip6_ctloutput() at netbsd:ip6_ctloutput+0x1748
    udp6_ctloutput() at netbsd:udp6_ctloutput+0xa2
    udp6_ctloutput_wrapper() at netbsd:udp6_ctloutput_wrapper+0x2c
    sosetopt() at netbsd:sosetopt+0x72
    sys_setsockopt() at netbsd:sys_setsockopt+0x8e
    syscall() at netbsd:syscall+0x299
    --- syscall (number 105) ---
    74e473921a9a:
    cpu1: End traceback...
    fatal breakpoint trap in supervisor mode
    trap type 1 code 0 rip 0xffffffff802219ed cs 0x8 rflags 0x202 cr2 0x74e473921a90 ilevel 0x4 rsp 0xffffc1004aabdb30
    curlwp 0xffffbb853ca90100 pid 1522.1522 lowest kstack 0xffffc1004aaba2c0


This one happens when an old 32-bit version of perl loads some modules:

    panic: kernel diagnostic assertion "M_LEADINGSPACE(m) >= (m->m_pkthdr.len - m->m_len)" failed: file "/devel/netbsd/current/src/sys/kern/uipc_mbuf.c", line 1684
    cpu0: Begin traceback...
    vpanic() at netbsd:vpanic+0x178
    kern_assert() at netbsd:kern_assert+0x48
    m_defrag() at netbsd:m_defrag+0x408
    xennet_start() at netbsd:xennet_start+0xc7
    if_transmit() at netbsd:if_transmit+0x120
    ether_output() at netbsd:ether_output+0x296
    ip_output() at netbsd:ip_output+0x1375
    tcp_output() at netbsd:tcp_output+0x199d
    tcp_send_wrapper() at netbsd:tcp_send_wrapper+0xa6
    sosend() at netbsd:sosend+0x80a
    soo_write() at netbsd:soo_write+0x42
    dofilewrite() at netbsd:dofilewrite+0x93
    sys_write() at netbsd:sys_write+0x49
    netbsd32_write() at netbsd:netbsd32_write+0x31
    netbsd32_syscall() at netbsd:netbsd32_syscall+-0x1f2c5e
    cpu0: End traceback...
    fatal breakpoint trap in supervisor mode
    trap type 1 code 0 rip 0xffffffff802219ed cs 0x8 rflags 0x202 cr2 0xf8b75484 ilevel 0x8 rsp 0xffffc1004b9327c0
    curlwp 0xffffbb8548442700 pid 2754.2754 lowest kstack 0xffffc1004b92f2c0