Re: [PATCH v5 0/4] uio: add MSI/MSI-X support to uio_pci_generic driver

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Oct 06, 2015 at 11:35:27PM +0300, Vlad Zolotarov wrote:
> 
> 
> On 10/06/15 21:27, Michael S. Tsirkin wrote:
> >On Tue, Oct 06, 2015 at 08:17:35PM +0300, Vlad Zolotarov wrote:
> >>This series add support for MSI and MSI-X interrupts to uio_pci_generic driver.
> >>
> >>Currently uio_pci_generic demands INT#x interrupts source be available. However
> >>there are devices that simply don't have INT#x capability, for instance SR-IOV
> >>VF devices that simply don't have INT#x capability. For such devices
> >>uio_pci_generic will simply fail (more specifically its probe() will fail).
> >>
> >>When IOMMU is either not available (e.g. Amazon EC2) or not acceptable due to
> >>performance overhead and thus VFIO is not an option users that develop
> >>user-space drivers are left without any option but to develop some proprietary
> >>UIO drivers (e.g. igb_uio driver in Intel's DPDK) just to be able to use UIO
> >>infrastructure.
> >>
> >>This series provides a generic solution for this problem while preserving the
> >>original behaviour for devices for which the original uio_pci_generic had worked
> >>before (i.e. INT#x will be used by default).
> >>
> >>New in v5:
> >>    - Expanded the commitlog on PATCH1.
> >Looks like you didn't attempt to address any of my review comments.
> >I don't intend to review this until you do.
> 
> So far there hasn't been any comments related to the code in these patches
> from your side but rather comments about the general flaws of the current
> uio_pci_generic in particular and UIO in general that have nothing to do
> with this series. Therefore obviously there was nothing to address.
> If u have any comments related to _THIS_ series I'd be glad to address. So
> far I was under the strong impression that u develop an obviously
> theoretical discussion about "nice to have fixed" stuff in UIO, which was
> obvious to everybody on this thread had nothing to do with this patch
> series.
> 
> Could it be that I've got u wrong? If so, could u, pls., clarify what u'd
> like me to fix in these patches exactly and why?
> 
> thanks,
> vlad

The issues I pointed out are not "nice to have fixed" at all.
The patchset isn't acceptable if you don't address them.
Sorry, I don't have the time to go over them again.
Please just dig them out of the archive.

> >
> >>New in v4:
> >>    - Use portable __u32 and __s32 types from asm/types.h for
> >>      defining uio_pci_generic_irq_set fields.
> >>    - Use proper _IO macros for defining read and write ioctl()
> >>      commands.
> >>    - Moved bars mapping setting into a separate patch.
> >>    - Update uio_pci_generic example in uio-howto.tmpl.
> >>
> >>New in v3:
> >>    - Add __iomem qualifier to temp buffer receiving ioremap value.
> >>New in v2:
> >>    - Added #include <linux/uaccess.h> to uio_pci_generic.c
> >>
> >>
> >>Vlad Zolotarov (4):
> >>   uio: add ioctl support
> >>   uio_pci_generic: properly initialize PCI bars mappings towards UIO
> >>   uio_pci_generic: add MSI/MSI-X support
> >>   Documentation: update uio-howto
> >>
> >>  Documentation/DocBook/uio-howto.tmpl | 139 ++++++++++--
> >>  drivers/uio/uio.c                    |  15 ++
> >>  drivers/uio/uio_pci_generic.c        | 409 +++++++++++++++++++++++++++++++++--
> >>  include/linux/uio_driver.h           |   3 +
> >>  include/uapi/linux/uio_pci_generic.h |  51 +++++
> >>  5 files changed, 574 insertions(+), 43 deletions(-)
> >>  create mode 100644 include/uapi/linux/uio_pci_generic.h
> >>
> >>-- 
> >>2.1.0