Re: [PATCH v2 18/19] block/nvme: Switch to using the MSIX API

[Philippe Mathieu-Daudé]

On 10/26/20 9:32 PM, Auger Eric wrote:
> Hi Philippe,
> 
> On 10/26/20 11:55 AM, Philippe Mathieu-Daudé wrote:
>> In preparation of using multiple IRQs, switch to using the recently
>> introduced MSIX API. Instead of allocating and assigning IRQ in
>> a single step, we now have to use two distinct calls.
>>
>> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  block/nvme.c | 14 ++++++++++++--
>>  1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/nvme.c b/block/nvme.c
>> index 46b09b3a3a7..191678540b6 100644
>> --- a/block/nvme.c
>> +++ b/block/nvme.c
>> @@ -693,6 +693,7 @@ static int nvme_init(BlockDriverState *bs, const char 
>> *device, int namespace,
>>      size_t device_page_size_min;
>>      size_t device_page_size_max;
>>      size_t iommu_page_size_min = 4096;
>> +    unsigned irq_count = MSIX_IRQ_COUNT;
>>  
>>      qemu_co_mutex_init(&s->dma_map_lock);
>>      qemu_co_queue_init(&s->dma_flush_queue);
>> @@ -809,8 +810,17 @@ static int nvme_init(BlockDriverState *bs, const char 
>> *device, int namespace,
>>          }
>>      }
>>  
>> -    ret = qemu_vfio_pci_init_irq(s->vfio, s->irq_notifier,
>> -                                 VFIO_PCI_MSIX_IRQ_INDEX, errp);
>> +    ret = qemu_vfio_pci_msix_init_irqs(s->vfio, &irq_count, errp);
>> +    if (ret) {
>> +        if (ret == -EOVERFLOW) {
>> +            error_append_hint(errp, "%u IRQs requested but only %u 
>> available\n",
>> +                              MSIX_IRQ_COUNT, irq_count);
> This message can be directly printed in qemu_vfio_pci_msix_init_irqs()

Good idea, thanks.