Message-ID: <1491360898.4536.63.camel@gmx.de>
Subject: Re: Random guest crashes since 5c34d002dcc7 ("virtio_pci: use
 shared interrupts for virtqueues")
From: Mike Galbraith <efault@gmx.de>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
        Thorsten Leemhuis <linux@leemhuis.info>,
        virtio-dev@lists.oasis-open.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        rjones@redhat.com
Date: Wed, 05 Apr 2017 04:54:58 +0200
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On Wed, 2017-04-05 at 00:31 +0300, Michael S. Tsirkin wrote:
> On Tue, Apr 04, 2017 at 08:38:35PM +0200, Mike Galbraith wrote:
> > On Tue, 2017-04-04 at 21:00 +0300, Michael S. Tsirkin wrote:
> > 
> > > And just making double sure, the 1st version that has the issue
> > > is 5c34d002dcc7, isn't it? I'm asking because subject says so
> > > but then goes on to list subject from another commit.
> > > This one is:
> > > 	> virtio_pci: remove struct virtio_pci_vq_info
> > 
> > When the hibernation related warnings started I don't know, I
> > wasn't
> > targeting that, those fell out of subsequent testing.
> > I started out
> > hunting console breakage point w. threaded irqs, which is
> > 5c34d002dcc7.
> 
> OK but 5c34d002dcc7 isn't "virtio_pci: use shared
> interrupts for virtqueues".

Heh, wrong sha.. $subject does however correctly identify in quotes the
origin of the threaded irq woes.
 
> I'm confused at this point. I would appreciate the summary of
> which versions were tested and what did you see. Testing
> a revert might also help.

I already tested full revert.  I went looking for what busted kvm for
RT kernels, extracted the virtio series and quilt bisected that to use
shared interrupts.  I was going to just use my little turn off
multiport hacklet to put spinning kworker on the back burner until the
dust settled, but noticed that there was more going on, and none of it
is RT specific (thus freeing up a back burner).

>From there, it's all test what you/Christoph post, as you post it, in
virgin source.

	-Mike