Re: [PATCH v2 17/19] util/vfio-helpers: Introduce qemu_vfio_pci_msix_set_irq()

[Auger Eric <eric.auger@redhat.com>]

Hi Philippe,

On 10/26/20 11:55 AM, Philippe Mathieu-Daudé wrote:
> Introduce qemu_vfio_pci_msix_set_irq() to set the event
> notifier of a specific MSIX IRQ. All other registered IRQs
> are left unmodified.
> 
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric

> ---
>  include/qemu/vfio-helpers.h |  2 ++
>  util/vfio-helpers.c         | 35 +++++++++++++++++++++++++++++++++++
>  util/trace-events           |  1 +
>  3 files changed, 38 insertions(+)
> 
> diff --git a/include/qemu/vfio-helpers.h b/include/qemu/vfio-helpers.h
> index 492072cba2f..4c06694e03a 100644
> --- a/include/qemu/vfio-helpers.h
> +++ b/include/qemu/vfio-helpers.h
> @@ -33,5 +33,7 @@ int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
>                             int irq_type, Error **errp);
>  int qemu_vfio_pci_msix_init_irqs(QEMUVFIOState *s,
>                                   unsigned *irq_count, Error **errp);
> +int qemu_vfio_pci_msix_set_irq(QEMUVFIOState *s, unsigned irq_index,
> +                               EventNotifier *notifier, Error **errp);
>  
>  #endif
> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
> index d88e2c7dc1f..18142e6be86 100644
> --- a/util/vfio-helpers.c
> +++ b/util/vfio-helpers.c
> @@ -232,6 +232,41 @@ int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
>      return 0;
>  }
>  
> +/**
> + * Initialize a MSIX IRQ and register its event notifier.
> + * @irq_index: MSIX IRQ index
> + * @notifier: notifier for the MSIX IRQ
> + */
> +int qemu_vfio_pci_msix_set_irq(QEMUVFIOState *s, unsigned irq_index,
> +                               EventNotifier *notifier, Error **errp)
> +{
> +    int r;
> +    int fd = event_notifier_get_fd(notifier);
> +    size_t irq_set_size;
> +    struct vfio_irq_set *irq_set;
> +
> +    trace_qemu_vfio_pci_msix_set_irq(irq_index, fd);
> +    irq_set_size = sizeof(*irq_set) + sizeof(int32_t);
> +    irq_set = g_malloc0(irq_set_size);
> +    /* Get to a known IRQ state */
> +    *irq_set = (struct vfio_irq_set) {
> +        .argsz = irq_set_size,
> +        .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
> +        .index = VFIO_PCI_MSIX_IRQ_INDEX,
> +        .start = irq_index,
> +        .count = 1,
> +    };
> +    ((int32_t *)&irq_set->data)[0] = fd;
> +    r = ioctl(s->device, VFIO_DEVICE_SET_IRQS, irq_set);
> +    g_free(irq_set);
> +    if (r) {
> +        error_setg_errno(errp, errno, "Failed to setup device interrupt #%u",
> +                         irq_index);
> +        return -errno;
> +    }
> +    return 0;
> +}
> +
>  /**
>   * Initialize device MSIX IRQs and register event notifiers.
>   * @irq_count: pointer to number of MSIX IRQs to initialize
> diff --git a/util/trace-events b/util/trace-events
> index ec93578b125..3a56c542a94 100644
> --- a/util/trace-events
> +++ b/util/trace-events
> @@ -88,6 +88,7 @@ qemu_vfio_dma_map(void *s, void *host, size_t size, bool temporary, uint64_t *io
>  qemu_vfio_dma_mapped(void *s, void *host, uint64_t iova, size_t size) "s %p host %p <-> iova 0x%"PRIx64" size 0x%zx"
>  qemu_vfio_dma_unmap(void *s, void *host) "s %p host %p"
>  qemu_vfio_msix_info_irqs(uint32_t count, unsigned asked) "msix irqs %"PRIu32" (asked: %u)"
> +qemu_vfio_pci_msix_set_irq(unsigned irq_index, int fd) "msix irq %u notifier_fd %d"
>  qemu_vfio_iommu_iova_pgsizes(uint64_t iova_pgsizes) "iommu page size bitmask: 0x%08"PRIx64
>  qemu_vfio_pci_read_config(void *buf, int ofs, int size, uint64_t region_ofs, uint64_t region_size) "read cfg ptr %p ofs 0x%x size %d (region ofs 0x%"PRIx64" size %"PRId64")"
>  qemu_vfio_pci_write_config(void *buf, int ofs, int size, uint64_t region_ofs, uint64_t region_size) "write cfg ptr %p ofs 0x%x size %d (region ofs 0x%"PRIx64" size %"PRId64")"
>