kern/55822: kernel panic in iavf0 attach

[kiers%original.xs4all.nl@localhost]

>Number:         55822
>Category:       kern
>Synopsis:       iavf0 attach: panic: kernel diagnostic assertion "!(pg->flags & PG_FREE)" failed: file "/home/kiers/git/NetBSD-current/src/sys/uvm/uvm_page.c", line 1449
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Nov 24 16:15:00 +0000 2020
>Originator:     kiers%original.xs4all.nl@localhost
>Release:        NetBSD 9.99.75 (GENERIC) #0: Mon Nov 23 18:10:03 CET 2020
>Organization:
	
>Environment:
Host is Freebsd 12.2 with X710 and X722 NICS, NetBSD-current in Bhyve
	
	
System: NetBSD 9.99.75 (GENERIC) #0: Mon Nov 23 18:10:03 CET 2020 kiers@esmeralda5:/tmp/obj/obj10592/sys/arch/amd64/compile/GENERIC
Architecture: x86_64
Machine: amd64
>Description:
	I have a FreeBSD 12.2 host with X710 and X722 NICs.  I try to pass one of them trough
	to a NetBSD 9.99.75 guest.  The kernel panics during iavf0 probing:

[   1.0342967] iavf0 at pci0 dev 2 function 0:unable to get VF interface version
[   1.0342967] panic: kernel diagnostic assertion "!(pg->flags & PG_FREE)" failed: file "/home/kiers/git/NetBSD-current/src/sys/uvm/uvm_page.c", line 1449 
[   1.0342967] cpu0: Begin traceback...
[   1.0342967] vpanic() at netbsd:vpanic+0x156
[   1.0342967] __x86_indirect_thunk_rax() at netbsd:__x86_indirect_thunk_rax
[   1.0342967] uvm_pagefree() at netbsd:uvm_pagefree+0x657
[   1.0342967] uvm_pglistfree() at netbsd:uvm_pglistfree+0x6b
[   1.0342967] _bus_dmamem_free.isra.0() at netbsd:_bus_dmamem_free.isra.0+0x8d
[   1.0342967] iavf_aqb_free() at netbsd:iavf_aqb_free+0x3b
[   1.0342967] iavf_attach() at netbsd:iavf_attach+0x3b1
[   1.0342967] config_attach_loc() at netbsd:config_attach_loc+0x182
[   1.0342967] pci_probe_device() at netbsd:pci_probe_device+0x585

...a lot more lines...

cpu_configure() at netbsd:cpu_configure+0x38
main() at netbsd:main+0x32c
ds          3840
es          37f0
fs          3830
gs          10
rdi         8
rsi         3f8
rbp         ffffffff81c23830
rbx         107e3c000
rdx         1
rcx         8
rax         1
r8          107e3c000
r9          53bb7
r10         1
r11         fffffffe
r12         104
r13         ffffffff813451f8    ostype+0xa88
r14         ffffffff81c23878
r15         ffffab9f3e512000
rip         ffffffff80221a25    breakpoint+0x5
cs          8
rflags      202
rsp         ffffffff81c23830
ss          10
netbsd:breakpoint+0x5:  leave
db{0}> bt
breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x156
__x86_indirect_thunk_rax() at netbsd:__x86_indirect_thunk_rax
uvm_pagefree() at netbsd:uvm_pagefree+0x657
uvm_pglistfree() at netbsd:uvm_pglistfree+0x6b
_bus_dmamem_free.isra.0() at netbsd:_bus_dmamem_free.isra.0+0x8d
iavf_aqb_free() at netbsd:iavf_aqb_free+0x3b
iavf_attach() at netbsd:iavf_attach+0x3b1
config_attach_loc() at netbsd:config_attach_loc+0x182
pci_probe_device() at netbsd:pci_probe_device+0x585
pci_enumerate_bus() at netbsd:pci_enumerate_bus+0x1b5
pcirescan() at netbsd:pcirescan+0x4e
pciattach() at netbsd:pciattach+0x186
config_attach_loc() at netbsd:config_attach_loc+0x182
mp_pci_scan() at netbsd:mp_pci_scan+0x9e
amd64_mainbus_attach() at netbsd:amd64_mainbus_attach+0x236
mainbus_attach() at netbsd:mainbus_attach+0x84
config_attach_loc() at netbsd:config_attach_loc+0x182
cpu_configure() at netbsd:cpu_configure+0x38
main() at netbsd:main+0x32c
db{0}> 

	
>How-To-Repeat:
	Probably just as simple as booting NetBSD-current in this configuration.

	FreeBSD guests run fine on this host.

	I have another host with FreeBSD 12.1 and different X540-AT2 NIC
	and that runs NetBSD 9.0 fine.  But that uses ixv(4) in the guest.
	
>Fix:
	

>Unformatted: