From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755948Ab1KOOfE (ORCPT ); Tue, 15 Nov 2011 09:35:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:15818 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755716Ab1KOOfC (ORCPT ); Tue, 15 Nov 2011 09:35:02 -0500 Date: Tue, 15 Nov 2011 16:36:20 +0200 From: "Michael S. Tsirkin" To: Amit Shah Cc: Rusty Russell , linux-kernel@vger.kernel.org, Virtualization List Subject: Re: [PATCH v2 09/11] virtio: net: Add freeze, restore handlers to support S4 Message-ID: <20111115143620.GA16609@redhat.com> References: <5b7834c9a30254220f9c079ba54d29abaf63db8f.1317311033.git.amit.shah@redhat.com> <20111002093324.GD29706@redhat.com> <20111115122902.GA26378@amit-x200.redhat.com> <20111115125127.GA31208@redhat.com> <20111115140346.GC26378@amit-x200.redhat.com> <20111115142259.GA16395@redhat.com> <20111115143149.GE26378@amit-x200.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111115143149.GE26378@amit-x200.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 15, 2011 at 08:01:49PM +0530, Amit Shah wrote: > On (Tue) 15 Nov 2011 [16:23:00], Michael S. Tsirkin wrote: > > On Tue, Nov 15, 2011 at 07:33:46PM +0530, Amit Shah wrote: > > > On (Tue) 15 Nov 2011 [14:51:27], Michael S. Tsirkin wrote: > > > > On Tue, Nov 15, 2011 at 05:59:36PM +0530, Amit Shah wrote: > > > > > On (Sun) 02 Oct 2011 [11:33:26], Michael S. Tsirkin wrote: > > > > > > On Thu, Sep 29, 2011 at 09:19:40PM +0530, Amit Shah wrote: > > > > > > > Remove all the vqs on hibernation and re-create them after restoring > > > > > > > from a hibernated image. This keeps networking working across > > > > > > > hibernation. > > > > > > > > > > > > > > Signed-off-by: Amit Shah > > > > > > > --- > > > > > > > drivers/net/virtio_net.c | 28 ++++++++++++++++++++++++++++ > > > > > > > 1 files changed, 28 insertions(+), 0 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > > > > > index dcd4b01..8b9ed43 100644 > > > > > > > --- a/drivers/net/virtio_net.c > > > > > > > +++ b/drivers/net/virtio_net.c > > > > > > > @@ -1131,6 +1131,30 @@ static void __devexit virtnet_remove(struct virtio_device *vdev) > > > > > > > free_netdev(vi->dev); > > > > > > > } > > > > > > > > > > > > > > +#ifdef CONFIG_PM > > > > > > > +static int virtnet_freeze(struct virtio_device *vdev) > > > > > > > +{ > > > > > > > + struct virtnet_info *vi = vdev->priv; > > > > > > > > > > > > I'm guessing we need to do something like netif_device_detach here, > > > > > > otherwise guest might be in the process of using the vq for transmit at > > > > > > this point. > > > > > > > > > > Done. > > > > > > > > > > > I think we also must make sure NAPI RX handler is not in progress. > > > > > > > > > > How to do that? napi_disable() / napi_enable() doesn't seem right > > > > > (and it doesn't work, too). pci_disable_device() in the suspend > > > > > routine may work? > > > > > > > > > > > We also might need to mask interrupts from the device > > > > > > to prevent TX or RX from getting rescheduled? > > > > > > > > > > pci_disable_device() will help this too, right? > > > > > > > > > > > > > No, why would it help? > > > > > > IRQs will be disabled after the call to pci_disable_device(), > > > isn't that sufficient? > > > > > > > They will? > > * pci_disable_device - Disable PCI device after use > > * @dev: PCI device to be disabled > > * > > * Signal to the system that the PCI device is not in use by the system > > * anymore. This only involves disabling PCI bus-mastering, if active. > > * > > * Note we don't actually disable the device until all callers of > > * pci_enable_device() have called pci_disable_device(). > > You mean multiple devices could have called pci_enable_device()? Not > likely to happen, at least in case of our virtio devices... only we > claim ownership over them. I don't think that'll change. > > Amit I simply mean that pci_disable_device does not seem to disable interrupts. -- MST