Red Hat Bugzilla – Bug 889410
[virtio-win][netkvm] Network fail to access remote computer after enable netkvm driver parameter "TestOnly.UseSwTxChecksum".
Last modified: 2013-11-21 19:00:40 EST
Description of problem:
Guest network fails to access remote computer after enable netkvm driver parameter "TestOnly.UseSwTxChecksum". But can ping remote computer from guest.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Start guest with CLI:
/usr/libexec/qemu-kvm -m 2G -smp 2 -cpu cpu64-rhel6,+x2apic -usb -device usb-tablet -drive file=2k8-R2-network.qcow2,format=qcow2,if=none,id=drive-ide0-0-0,werror=stop,rerror=stop,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,mac=00:10:16:23:78:01,bus=pci.0,addr=0x4,id=net0 -uuid 93467808-bc3f-40ec-82be-0d8f50b5b862 -rtc base=localtime -no-kvm-pit-reinjection -monitor stdio -name win2k8-R2-network -spice disable-ticketing,port=5931 -vga qxl -global PIIX4_PM.disable_s3=0 -global PIIX4_PM.disable_s4=0
2.Enable netkvm parameter "TestOnly.UseSwTxChecksum" from Device Manager --> Network adapters--> right-click PropertiesRedhat VirIO Ethernet Adapter---> Properties---> Advanced
3.Click Start --> Run and try to access shared folder on the remote computer such as \\10.66.73.47
Network fail to access remote computer with error dialogue prompt "Windows can not access \\10.66.73.47".When change to disable, it works well again.
Network should work well after enable netkvm driver parameter "TestOnly.UseSwTxChecksum".
Tried on rhel6.3 with driver virtio-win-1.5.3,network can work without any error.
This is very minor bug. "TestOnly" parameters shouldn't be changed for in production environment and are intended for debugging only (I am thinking to remove them at all so they won't confuse anyone). TestOnly.UseSwTxChecksum - should emulate all offloads in the driver instead of using host capabilities. This is definitely test only mode as it will diminish the performance, it was used a really long time ago to pass WHQL when the offload in host\QEMU was unstable. I don't think now it is even make sense to invest in keeping this code alive.
Probably this code needs to be removed. Anyhow, postponed to 6.5.
test on version virtio-win-prewhql-49 also hit the same issue
Version-Release number of selected component:
Red Hat Enterprise Linux Server release 6.4 (Santiago)
(In reply to comment #7)
> test on version virtio-win-prewhql-49 also hit the same issue
> Version-Release number of selected component:
> Red Hat Enterprise Linux Server release 6.4 (Santiago)
my mistake,the version of virtio-win I tested is virtio-win-prewhql-54 instead of virtio-win-prewhql-49
Removed from Vista and up:
Reproduced this issue on build 49
Verified this issue on build 64
steps same as comment #0
on build 49, Network fail to access remote computer with error dialogue prompt "Windows can not access \\10.66.73.47".
on build 64 ,Network can access to remote computer and do copy operation.
Based on above ,this issue has been fixed already .
retest this issue on build 65,guest can access to remote computer with "TestOnly.UseSwTxChecksum" enabled.
So this issue has been fixed.
Move status to VERIFIED according to comment #14&comment #15
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.