[dpdk-dev] [PATCH] vfio: set IOMMU type for the container once

[Alejandro Lucero]

The patch is OK for me. I have run tests with that change with no problems.
But I can just run tests with devices where each one got its own IOMMU
group, so my ack is just for that case (although theoretically this patch
fixes the other case). I'm looking at doing some changes to the kernel for
being able to have an scenario with several devices sharing same IOMMU
group just for the shake of testing.

By other hand, vfio hotplug has a problem when there are several devices in
same IOMMU group being plugged and unplugged. I have a patch ready for
fixing this issue which I will send soon.

On Fri, Apr 21, 2017 at 11:12 AM, gowrishankar muthukrishnan <
gowrishankar.m at linux.vnet.ibm.com> wrote:

> Could this patch be reviewed and merged for 17.05 rc3 ?. It solved
> regression with i40e pmd
> bring up in one of our ppc64le server models through vfio-pci pci module.
>
> Thanks Alexey pointing out this in one of your patches.
>
> Regards,
> Gowrishankar
>
>
> On Tuesday 04 April 2017 09:36 PM, Andrew Rybchenko wrote:
>
>> If more than one used PCI device belongs to one IOMMU group,
>> it is still one IOMMU group and the container IOMMU type
>> should be set only once.
>>
>> Fixes: 94c0776b1bad ("vfio: support hotplug")
>>
>> Signed-off-by: Andrew Rybchenko <arybchenko at solarflare.com>
>> ---
>> My testing of the patch is limitted to my configuration with 2 PCI
>> functions which belong to one IOMMU group.
>>
>>   lib/librte_eal/linuxapp/eal/eal_vfio.c | 54
>> ++++++++++++++++++----------------
>>   1 file changed, 29 insertions(+), 25 deletions(-)
>>
>> diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c
>> b/lib/librte_eal/linuxapp/eal/eal_vfio.c
>> index 6e2e84c..dd59c1c 100644
>> --- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
>> +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
>> @@ -298,33 +298,37 @@ vfio_setup_device(const char *sysfs_base, const
>> char *dev_addr,
>>                         clear_group(vfio_group_fd);
>>                         return -1;
>>                 }
>> -       }
>>
>> -       /*
>> -        * pick an IOMMU type and set up DMA mappings for container
>> -        *
>> -        * needs to be done only once, only when first group is assigned
>> to
>> -        * a container and only in primary process. Note this can happen
>> several
>> -        * times with the hotplug functionality.
>> -        */
>> -       if (internal_config.process_type == RTE_PROC_PRIMARY &&
>> -                       vfio_cfg.vfio_active_groups == 1) {
>> -               /* select an IOMMU type which we will be using */
>> -               const struct vfio_iommu_type *t =
>> +               /*
>> +                * pick an IOMMU type and set up DMA mappings for
>> container
>> +                *
>> +                * needs to be done only once, only when first group is
>> +                * assigned to a container and only in primary process.
>> +                * Note this can happen several times with the hotplug
>> +                * functionality.
>> +                */
>> +               if (internal_config.process_type == RTE_PROC_PRIMARY &&
>> +                               vfio_cfg.vfio_active_groups == 1) {
>> +                       /* select an IOMMU type which we will be using */
>> +                       const struct vfio_iommu_type *t =
>>                                 vfio_set_iommu_type(vfio_cfg.v
>> fio_container_fd);
>> -               if (!t) {
>> -                       RTE_LOG(ERR, EAL, "  %s failed to select IOMMU
>> type\n", dev_addr);
>> -                       close(vfio_group_fd);
>> -                       clear_group(vfio_group_fd);
>> -                       return -1;
>> -               }
>> -               ret = t->dma_map_func(vfio_cfg.vfio_container_fd);
>> -               if (ret) {
>> -                       RTE_LOG(ERR, EAL, "  %s DMA remapping failed, "
>> -                                       "error %i (%s)\n", dev_addr,
>> errno, strerror(errno));
>> -                       close(vfio_group_fd);
>> -                       clear_group(vfio_group_fd);
>> -                       return -1;
>> +                       if (!t) {
>> +                               RTE_LOG(ERR, EAL,
>> +                                       "  %s failed to select IOMMU
>> type\n",
>> +                                       dev_addr);
>> +                               close(vfio_group_fd);
>> +                               clear_group(vfio_group_fd);
>> +                               return -1;
>> +                       }
>> +                       ret = t->dma_map_func(vfio_cfg.vfio_
>> container_fd);
>> +                       if (ret) {
>> +                               RTE_LOG(ERR, EAL,
>> +                                       "  %s DMA remapping failed, error
>> %i (%s)\n",
>> +                                       dev_addr, errno, strerror(errno));
>> +                               close(vfio_group_fd);
>> +                               clear_group(vfio_group_fd);
>> +                               return -1;
>> +                       }
>>                 }
>>         }
>>
>>
>