Realtek r8169 doesn't work reliable on Qubes 1.0-RC1

[Hakisho Nukama]

I've encountered a drop of pakets with Realtek RTL8111DL Gigabit
Ethernet Controller.

[ 6.362766] r8169 0000:00:00.0: eth0: RTL8168d/8111d at
0xffffc900003be000, 00:30:67:31:5c:3b, XID 081000c0 IRQ 34
[ 6.363008] r8169 0000:00:00.0: eth0: jumbo features [frames: 9200
bytes, tx checksumming: ko]
[ 13.586103] r8169 0000:00:00.0: eth0: link down
[ 13.586286] r8169 0000:00:00.0: eth0: link down
[ 13.586405] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 15.704703] r8169 0000:00:00.0: eth0: link up
[ 15.704746] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 15.714607] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 15.736110] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 20.208661] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 20.209928] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 20.459871] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 20.711001] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 20.911815] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 21.280605] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 21.676104] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 21.983601] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 23.420691] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 24.222089] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 25.684136] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 26.684149] eth0: no IPv6 routers present
[ 82.495472] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 83.492101] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 84.492090] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 85.492349] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 86.492106] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 87.492093] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 96.005093] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 97.004098] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 97.809581] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 98.004097] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 98.677293] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 98.817835] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 124.484159] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 126.484141] r8169 0000:00:00.0: eth0: Failed to map TX DMA!
[ 128.484146] r8169 0000:00:00.0: eth0: Failed to map TX DMA!

Best Regards,
Hakisho Nukama

[Joanna Rutkowska]

How much memory your netvm has? Probably the standard 200MB? If so, try
to allocate some more, say 400 MB.

joanna.

ps. Of course, most VMs in Qubes gets memory automatically thanks to our
qmemman daemon, but netvms (and generally any VMs that have PCI devices
assigned) are exception to this rule and they are assigned fixed amount
of memory.

[Marek Marczykowski]

Also you can play with netvm kernel parameters - by default there is
"iommu=soft swiotlb=2048" - you can try to increase swiotlb - try values like
4096, 8192 etc. This parameter control how much memory will be prepared for
DMA transfers (in units of 2kb).

--
Best Regards / Pozdrawiam,
Marek Marczykowski
Invisible Things Lab

[Joanna Rutkowska]

... and you can tweak all those params using qvm-prefs command line tool:

https://wiki.qubes-os.org/trac/wiki/Dom0Tools/QvmPrefs

(You can also use the graphical manager for memory adjustment)

joanna.

[Hakisho Nukama]

Memory of netvm was left on its initial value (200 MB).

Increasing initial memory allocation (400 MB) alone doesn't work,
setting swiotlb to 4096 does work.
So setting swiotlb to 4096 solves this issue (in this short test period).

Thanks for your help Joanna and Marek.

Best Regards,
Hakisho Nukama

[Marek Marczykowski]

Can you try swiotlb=4096, but memory 200MB?