Re: PCI passthrough issue

[Jean Baptiste Favre <xen-devel@jbfavre.org>]

Hello again,
Just tried without Xen network driver and got the same behaviour.
Would say hopefully because removing xen network driver prevent me to
use my domU as firewall for dom0 as I intented to do.

BTW, have no idea left :-/
Regards,
JB


Le 12/01/2011 16:53, Jean Baptiste Favre a écrit :
> Hello Konrad,
> 
> Le 12/01/2011 16:43, Konrad Rzeszutek Wilk a écrit :
>> On Wed, Jan 12, 2011 at 04:38:49PM +0100, Jean Baptiste Favre wrote:
>>> Hello,
>>> I'm facing a strange issue with network card PCI passthrough on my
>>> openwrt test domU.
>>>
>>> - With network PCI passthrough, DNS lookup failed for some domains
>>> (exemple, google.com) but not for other (free.fr my ISP, or my domain
>>> jbfavre.org). I can ping an IP address without any problem.
>>
>> Do you have "both" (so PCI passthrough and the Xen network driver)
>> in the guest? If so, have you tried eliminating the xen network driver
>> to see if it is just a routing issue?
> Have not tried to eliminate xen network driver. Think I have both drivers.
> 
> My kernel .config looks like:
> $ grep XEN build_dir/linux-x86_xen_domu/linux-2.6.37/.config
> CONFIG_XEN=y
> # CONFIG_XEN_PRIVILEGED_GUEST is not set
> CONFIG_XEN_PVHVM=y
> CONFIG_XEN_MAX_DOMAIN_MEMORY=128
> CONFIG_XEN_SAVE_RESTORE=y
> CONFIG_PCI_XEN=y
> CONFIG_XEN_PCIDEV_FRONTEND=y
> CONFIG_XEN_BLKDEV_FRONTEND=y
> CONFIG_XEN_NETDEV_FRONTEND=y
> CONFIG_HVC_XEN=y
> CONFIG_XEN_BALLOON=y
> CONFIG_XEN_SCRUB_PAGES=y
> CONFIG_XEN_DEV_EVTCHN=y
> CONFIG_XENFS=y
> CONFIG_XEN_COMPAT_XENFS=y
> CONFIG_XEN_SYS_HYPERVISOR=y
> # CONFIG_XEN_PLATFORM_PCI is not set
> CONFIG_SWIOTLB_XEN=y
> 
> So, I should remove CONFIG_XEN_NETDEV_FRONTEND ?
> 
>> What does your routing table look like? Your IP table?
> My routing table is pretty clean, nothing strange here
> # route -n
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use
> Iface
> 10.0.0.0        0.0.0.0         255.255.255.0   U     0      0        0
> br-wan
> 0.0.0.0         10.0.0.1        0.0.0.0         UG    0      0        0
> br-wan
> 
>>> - Starting domU as a "normal" (ie without PCI passthrough), no problem.
>>>
>>>
>>> As far as I can say, domU is not the root cause. I really think this is
>>> related to PCI passsthrough. This seems to be related to packet length.
>>
>> Then that would imply the MTU is not set right. 
> Already checked it: 1500 :)
> 
>>> Did not see anything strange in dom0 logs.
>>>
>>> Is there any incompatibility between 2.6.32 dom0 kernel with Xen 4.0.1
>>> and 2.6.37 domU kernel ?
>>
>> No.
> So, will try to remove Xen Network driver and see what happen.
> 
> Regards,
> JB
> 
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