linux-kernel - Re: [PULL] virtio and lguest

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]

Message-ID: <87fwfkjpxc.fsf@rustcorp.com.au>
Date:	Fri, 13 Jan 2012 12:59:19 +1030
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	lkml - Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Amit Shah <amit.shah@...hat.com>,
	Christoph Hellwig <hch@....de>, Davidlohr Bueso <dave@....org>,
	Jacek Galowicz <jacek@...owicz.de>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Sasha Levin <levinsasha928@...il.com>,
	Stratos Psomadakis <psomas@...ab.ece.ntua.gr>,
	virtualization@...ts.linux-foundation.org
Subject: Re: [PULL] virtio and lguest

On Thu, 12 Jan 2012 16:29:14 -0800, Linus Torvalds <torvalds@...ux-foundation.org> wrote:
> On Wed, Jan 11, 2012 at 9:22 PM, Rusty Russell <rusty@...tcorp.com.au> wrote:
> >
> > Amit Shah (12):
> >      virtio: pci: switch to new PM API
> 
> Hmm. Afaik, this is broken, or at least not complete.
> 
> Sure, it switches to the new PM API, but it still does the PCI ops itself.
> 
> It should not need to - the PCI layer will do the power state and
> standard PCI device state saving. And setting the PCI_D3hot state when
> shared interrupts can still happen at suspend time is just a bad idea.
> 
> So I think you're doing extra work and introducing bugs by doing so -
> the default PCI bus operations should already do all you do, just do
> it better. And then you can use the SIMPLE_DEV_PM_OPS() to build the
> dev_pm_ops structure and get all the normal cases right automatically.
> 
> I don't know if there is any particularly good example of this, but
> you can see some of the network drivers for examples of this. Notice
> how they don't need to worry about PCI power states etc at all, they
> just need to worry about the actual chip suspend/resume (and for a
> network driver, you'd do the netif_device_detach/netif_device_attach
> etc)

Ok, I'll confess complete ignorance, and wait for Amit to respond.  I
must admit that PM for virtual devices is not a personal priority...

Thanks,
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/