Re: [RFC PATCH 2/3] util/vfio-helpers: Add trace event to display device IRQs available

[Alex Williamson <alex.williamson@redhat.com>]

On Tue, 11 Aug 2020 19:28:44 +0200
Philippe Mathieu-Daudé <philmd@redhat.com> wrote:

> Add a trace event to display the amount of IRQs available
> on the device.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  util/vfio-helpers.c | 1 +
>  util/trace-events   | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c
> index 6defefcc01..3ad7e6be52 100644
> --- a/util/vfio-helpers.c
> +++ b/util/vfio-helpers.c
> @@ -192,6 +192,7 @@ int qemu_vfio_pci_init_irq(QEMUVFIOState *s, EventNotifier *e,
>          error_setg(errp, "Device interrupt doesn't support eventfd");
>          return -EINVAL;
>      }
> +    trace_qemu_vfio_pci_init_irq(irq_info.count);
>  
>      irq_set_size = sizeof(*irq_set) + sizeof(int32_t);
>      irq_set = g_malloc0(irq_set_size);
> diff --git a/util/trace-events b/util/trace-events
> index 0ce42822eb..351dbdbe3c 100644
> --- a/util/trace-events
> +++ b/util/trace-events
> @@ -83,3 +83,4 @@ qemu_vfio_new_mapping(void *s, void *host, size_t size, int index, uint64_t iova
>  qemu_vfio_do_mapping(void *s, void *host, size_t size, uint64_t iova) "s %p host %p size %zu iova 0x%"PRIx64
>  qemu_vfio_dma_map(void *s, void *host, size_t size, bool temporary, uint64_t *iova) "s %p host %p size %zu temporary %d iova %p"
>  qemu_vfio_dma_unmap(void *s, void *host) "s %p host %p"
> +qemu_vfio_pci_init_irq(uint32_t count) "device interrupt count: %"PRIu32

Knowing the count independent of which index we're looking at doesn't
seem very useful.  Thanks,

Alex