On Fri, Jan 9, 2015 at 9:39 AM, Eric Auger <eric.auger@linaro.org> wrote:
> Hi Antonios,
>
> when moving to 3.19rc3 I observe a regression with my xgmac use case
> (real-time change?).
>
> I guess what happens is when I kill a first qemu session, guest does not
> have time to complete the virtual IRQ and the unmask is not performed by
> the virqfd handler. When starting a new QEMU session, the irqfd
> signalling is put in place again but since the masked field is set, the
> IRQ is left unmasked (v11 modification in vfio_set_trigger).
>
> The problem is that we don't discriminate between user mask action and
> automasked handler action. In case the user did not mask, I think we
> should reset the masked field when doing the free_irq. What do you think?

Hello Eric,

I agree, we should reset the masked field for future users.

Best regards
Antonios

>
> Best Regards
>
> Eric
>
> On 01/06/2015 11:48 AM, Antonios Motakis wrote:
>> This patch series aims to implement VFIO support for platform devices that
>> reside behind an IOMMU. Examples of such devices are devices behind an ARM
>> SMMU, or behind a Samsung Exynos System MMU.
>>
>> The API used is based on the existing VFIO API that is also used with PCI
>> devices. Only devices that include a basic set of IRQs and memory regions are
>> targeted; devices with complex relationships with other devices on a device
>> tree are not taken into account at this stage.
>>
>> This patch series may be applied on the following series/patches:
>>  - [PATCH] driver core: amba: add device binding path 'driver_override'
>>  - [PATCH v3 0/6] vfio: type1: support for ARM SMMUS with VFIO_IOMMU_TYPE1
>>
>> A copy can be cloned from the branch vfio-platform-v11 at:
>> git-9UaJU3cA/F/QT0dZR+AlfA@public.gmane.org:virtualopensystems/linux-kvm-arm.git
>>
>> Changes since v10:
>>  - Check if interrupt is already masked when setting a new trigger
>>  - Fixed kasprintf with unchecked return value in VFIO AMBA driver
>> Changes since v9:
>>  - Reworked the splitting of the patches that decouple virqfd from PCI
>>  - Some styling issues and typos
>>  - Removed superfluous includes
>>  - AMBA devices are now named vfio-amba- suffixed by the AMBA device id
>>  - Several other cleanups and fixes
>> Changes since v8:
>>  - Separate irq handler for edge and level triggered interrupts
>>  - Mutex based lock for VFIO fd open/release
>>  - Fixed bug where the first region of a platform device wasn't exposed
>>  - Read only regions can be MMAPed only read only
>>  - Code cleanups
>> Changes since v7:
>>  - Some initial placeholder functionality for PIO resources
>>  - Cleaned up code for IRQ triggering, masking and unmasking
>>  - Some functionality has been removed from this series and posted separately:
>>    - VFIO_IOMMU_TYPE1 support for ARM SMMUs
>>    - IOMMU NOEXEC patches
>>    - driver_override functionality for AMBA devices
>>  - Several fixes
>> Changes since v6:
>>  - Integrated support for AMBA devices
>>  - Numerous cleanups and fixes
>> Changes since v5:
>>  - Full eventfd support for IRQ masking and unmasking.
>>  - Changed IOMMU_EXEC to IOMMU_NOEXEC, along with related flags in VFIO.
>>  - Other fixes based on reviewer comments.
>> Changes since v4:
>>  - Use static offsets for each region in the VFIO device fd
>>  - Include patch in the series for the ARM SMMU to expose IOMMU_EXEC
>>    availability via IOMMU_CAP_DMA_EXEC
>>  - Rebased on VFIO multi domain support:
>>    - IOMMU_EXEC is now available if at least one IOMMU in the container
>>      supports it
>>    - Expose IOMMU_EXEC if available via the capability VFIO_IOMMU_PROT_EXEC
>>  - Some bug fixes
>> Changes since v3:
>>  - Use Kim Phillips' driver_probe_device()
>> Changes since v2:
>>  - Fixed Read/Write and MMAP on device regions
>>  - Removed dependency on Device Tree
>>  - Interrupts support
>>  - Interrupt masking/unmasking
>>  - Automask level sensitive interrupts
>>  - Introduced VFIO_DMA_MAP_FLAG_EXEC
>>  - Code clean ups
>>
>> Antonios Motakis (20):
>>   vfio/platform: initial skeleton of VFIO support for platform devices
>>   vfio: platform: probe to devices on the platform bus
>>   vfio: platform: add the VFIO PLATFORM module to Kconfig
>>   vfio: amba: VFIO support for AMBA devices
>>   vfio: amba: add the VFIO for AMBA devices module to Kconfig
>>   vfio/platform: return info for bound device
>>   vfio/platform: return info for device memory mapped IO regions
>>   vfio/platform: read and write support for the device fd
>>   vfio/platform: support MMAP of MMIO regions
>>   vfio/platform: return IRQ info
>>   vfio/platform: initial interrupts support code
>>   vfio/platform: trigger an interrupt via eventfd
>>   vfio/platform: support for level sensitive interrupts
>>   vfio: add a vfio_ prefix to virqfd_enable and virqfd_disable and
>>     export
>>   vfio: virqfd: rename vfio_pci_virqfd_init and vfio_pci_virqfd_exit
>>   vfio: add local lock for virqfd instead of depending on VFIO PCI
>>   vfio: pass an opaque pointer on virqfd initialization
>>   vfio: move eventfd support code for VFIO_PCI to a separate file
>>   vfio: initialize the virqfd workqueue in VFIO generic code
>>   vfio/platform: implement IRQ masking/unmasking via an eventfd
>>
>>  drivers/vfio/Kconfig                          |   1 +
>>  drivers/vfio/Makefile                         |   5 +-
>>  drivers/vfio/pci/vfio_pci.c                   |   8 -
>>  drivers/vfio/pci/vfio_pci_intrs.c             | 238 +-----------
>>  drivers/vfio/pci/vfio_pci_private.h           |   3 -
>>  drivers/vfio/platform/Kconfig                 |  19 +
>>  drivers/vfio/platform/Makefile                |   8 +
>>  drivers/vfio/platform/vfio_amba.c             | 115 ++++++
>>  drivers/vfio/platform/vfio_platform.c         | 103 +++++
>>  drivers/vfio/platform/vfio_platform_common.c  | 520 ++++++++++++++++++++++++++
>>  drivers/vfio/platform/vfio_platform_irq.c     | 340 +++++++++++++++++
>>  drivers/vfio/platform/vfio_platform_private.h |  82 ++++
>>  drivers/vfio/vfio.c                           |   8 +
>>  drivers/vfio/virqfd.c                         | 213 +++++++++++
>>  include/linux/vfio.h                          |  27 ++
>>  include/uapi/linux/vfio.h                     |   2 +
>>  16 files changed, 1456 insertions(+), 236 deletions(-)
>>  create mode 100644 drivers/vfio/platform/Kconfig
>>  create mode 100644 drivers/vfio/platform/Makefile
>>  create mode 100644 drivers/vfio/platform/vfio_amba.c
>>  create mode 100644 drivers/vfio/platform/vfio_platform.c
>>  create mode 100644 drivers/vfio/platform/vfio_platform_common.c
>>  create mode 100644 drivers/vfio/platform/vfio_platform_irq.c
>>  create mode 100644 drivers/vfio/platform/vfio_platform_private.h
>>  create mode 100644 drivers/vfio/virqfd.c
>>
>