On 20/03/2019 06:20, Leo Yan wrote:
> Since INTx only uses 2 FDs, it's not particularly useful to reserve FDs
> in function vfio_pci_enable_intx(); so this patch is to remove FDs
> reservation in this function.
>
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
The main reason for this is that we want to call enable_intx() multiple
times and reserve_irq_fds() increments a static variable. That function
makes an approximation of the number of fds used by kvmtool and given
that we count a margin of 100 fds, the 2 INTx fds are already included
in that approximation (assuming we're not assigning hundreds of devices
to the guest).
But given that patch 3 highlights the need for a one-time init function,
maybe we can move the reserve_irq_fds() call there as well?
Thanks,
Jean
> ---
> vfio/pci.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/vfio/pci.c b/vfio/pci.c
> index 5224fee..d025581 100644
> --- a/vfio/pci.c
> +++ b/vfio/pci.c
> @@ -1025,8 +1025,6 @@ static int vfio_pci_enable_intx(struct kvm *kvm, struct vfio_device *vdev)
> .index = VFIO_PCI_INTX_IRQ_INDEX,
> };
>
> - vfio_pci_reserve_irq_fds(2);
> -
> ret = ioctl(vdev->fd, VFIO_DEVICE_GET_IRQ_INFO, &irq_info);
> if (ret || irq_info.count == 0) {
> vfio_dev_err(vdev, "no INTx reported by VFIO");
>
