Re: [dpdk-dev] [PATCH 1/3] vfio: revert change that does intr eventfd setup at probe

["Nowak, DamianX" <damianx.nowak@intel.com>]

Hi,

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Nithin Dabilpuram
> Sent: Wednesday, July 17, 2019 13:59
> To: Hyong Youb Kim <hyonkim@cisco.com>; David Marchand
> <david.marchand@redhat.com>; Thomas Monjalon
> <thomas@monjalon.net>; Yigit, Ferruh <ferruh.yigit@intel.com>; Burakov,
> Anatoly <anatoly.burakov@intel.com>
> Cc: jerinj@marvell.com; John Daley <johndale@cisco.com>; Shahed Shaikh
> <shshaikh@marvell.com>; dev@dpdk.org; Nithin Dabilpuram
> <ndabilpuram@marvell.com>
> Subject: [dpdk-dev] [PATCH 1/3] vfio: revert change that does intr eventfd
> setup at probe
> 
> This reverts commit 89aac60e0be9ed95a87b16e3595f102f9faaffb4.
> "vfio: fix interrupts race condition"
> 
> The above mentioned commit moves the interrupt's eventfd setup to probe
> time but only enables one interrupt for all types of interrupt handles i.e
> VFIO_MSI, VFIO_LEGACY, VFIO_MSIX, UIO.
> It works fine with default case but breaks below cases specifically for MSIX
> based interrupt handles.
> 
> * Applications like l3fwd-power that request rxq interrupts
>   while ethdev setup.
> * Drivers that need > 1 MSIx interrupts to be configured for
>   functionality to work.
> 
> VFIO PCI for MSIx expects all the possible vectors to be setup up when using
> VFIO_IRQ_SET_ACTION_TRIGGER so that they can be allocated from kernel
> pci subsystem. Only way to increase the number of vectors later is first free
> all by using VFIO_IRQ_SET_DATA_NONE with action trigger and then enable
> new vector count.
> 
> Above commit changes the behavior of rte_intr_[enable|disable] to only
> mask and unmask unlike earlier behavior and thereby breaking above two
> scenarios.
> 
> Fixes: 89aac60e0be9 ("vfio: fix interrupts race condition")
> Cc: david.marchand@redhat.com
> 
> Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> Signed-off-by: Jerin Jacob <jerinj@marvell.com>
> ---
>  drivers/bus/pci/linux/pci_vfio.c          |  78 ++++++------
>  lib/librte_eal/linux/eal/eal_interrupts.c | 201 +++++++++++++++++++++++-
> ------

I can confirm this patch fixes "EAL:   error configuring interrupt" issue on my C6XX board
Damian