Re: [dpdk-dev] [PATCH] net/virtio: fix fail to configure rxq interrupt

["Hu, Jiayu" <jiayu.hu@intel.com>]

Hi Yuanhan,

> -----Original Message-----
> From: Yuanhan Liu [mailto:yliu@fridaylinux.org]
> Sent: Monday, July 31, 2017 11:47 AM
> To: Hu, Jiayu <jiayu.hu@intel.com>
> Cc: Tan, Jianfeng <jianfeng.tan@intel.com>; dev@dpdk.org
> Subject: Re: [PATCH] net/virtio: fix fail to configure rxq interrupt
> 
> On Mon, Jul 31, 2017 at 02:47:13AM +0000, Hu, Jiayu wrote:
> > Hi Yuanhan,
> >
> > When we run l3fwd-power in VM with applying this patch in VM DPDK,
> QEMU will crash. I think this patch can't solve the problem correctly but I
> haven't figured out the reason. I am so sorry about it.
> 
> It's okay. But you should reply earlier here, so that I would not apply it.
> 
> Regarding the crash, I believe Jianfeng had met a similar issue before. IIRC,
> it's about the order of event fd setups (or something like it). You might
> want to contact him for more details.

The root cause is that the interrupt should be set up before DRIVER_OK
is sent to QEMU. Otherwise, QEMU will crash.

The simplest way to enable RXQ interrupt after devices are initialized is to
re-init them via virtio_init_devices(), rather than to call virtio_configure_intr()
directly. This is also what Jianfeng does originally.

BRs,
Jiayu
> 
> And it's dropped.
> 
> 	--yliu
> 
> > > -----Original Message-----
> > > From: Yuanhan Liu [mailto:yliu@fridaylinux.org]
> > > Sent: Monday, July 31, 2017 10:30
> > > To: Hu, Jiayu <jiayu.hu@intel.com>
> > > Cc: dev@dpdk.org; Tan, Jianfeng <jianfeng.tan@intel.com>; Yao, Lei A
> > > <lei.a.yao@intel.com>; stable@dpdk.org
> > > Subject: Re: [PATCH] net/virtio: fix fail to configure rxq interrupt
> > >
> > > On Wed, Jul 19, 2017 at 11:18:23AM +0800, Jiayu Hu wrote:
> > > > When use rte_eth_dev_configure() to enable rx queue interrupt for
> virtio
> > > > devices, virtio_configure_intr() isn't called to set up the interrupt
> > > > environment, which causes rx queue interrupt setup failed. This patch is
> > > > to fix this issue.
> > > >
> > > > Fixes: 26b683b4f7d0 ("net/virtio: setup Rx queue interrupts")
> > > > Cc: stable@dpdk.org
> > > >
> > > > Signed-off-by: Jiayu Hu <jiayu.hu@intel.com>
> > >
> > > Applied to dpdk-next-virtio.
> > >
> > > Thanks.
> > >
> > > 	--yliu