netdev - Re: tap/bridge: Dropping NETIF_F_GSO/NETIF_F

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 16 May 2011 10:28:46 +0300
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Michał Mirosław <mirq-linux@...e.qmqm.pl>
Cc:	netdev@...r.kernel.org, Ben Hutchings <bhutchings@...arflare.com>,
	herbert@...dor.hengli.com.au
Subject: Re: tap/bridge: Dropping NETIF_F_GSO/NETIF_F_SG

On Thu, May 05, 2011 at 05:26:44PM +0200, Michał Mirosław wrote:
> On Wed, May 04, 2011 at 09:18:14PM +0300, Michael S. Tsirkin wrote:
> > BTW, I just noticed that net-next spits out
> > many of the following when I run any VMs:
> [...]
> > tap0: Features changed: 0x40004040 -> 0x401b4849
> 
> Before this message, userspace called ioctl(TIOCSETOFFLOAD)
> turning offloads on.
> 
> > tap0: Dropping NETIF_F_SG since no checksum feature.
> > tap0: Dropping NETIF_F_GSO since no SG feature.
> > tap0: Features changed: 0x401b4849 -> 0x40004040
> 
> And then it probably called ioctl(TIOCSETOFFLOAD) again, disabling them.
> 
> Best Regards,
> Michał Mirosław


I'd have to look at this some more, but I know qemu-kvm
supports offloads with current kernels.
There seems to be some kernel behaviour change here.

> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html