On Thu, Feb 2, 2023 at 9:42 AM Alvaro Karsz <alvaro.karsz@xxxxxxxxxxxxx> wrote:
>
> Add a print explaining why vhost_vdpa_alloc_domain failed if the device
> is not IOMMU cache coherent capable.
>
> Without this print, we have no hint why the operation failed.
>
> For example:
>
> $ virsh start <domain>
> error: Failed to start domain <domain>
> error: Unable to open '/dev/vhost-vdpa-<idx>' for vdpa device:
> Unknown error 524
>
> Suggested-by: Eugenio Perez Martin <eperezma@xxxxxxxxxx>
> Signed-off-by: Alvaro Karsz <alvaro.karsz@xxxxxxxxxxxxx>
>
Acked-by: Eugenio Pérez Martin <eperezma@xxxxxxxxxx>
Thanks!
> ---
> v2:
> - replace dev_err with dev_warn_once.
>
> drivers/vhost/vdpa.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 23db92388393..135f8aa70fb2 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -1151,8 +1151,11 @@ static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
> if (!bus)
> return -EFAULT;
>
> - if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY))
> + if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) {
> + dev_warn_once(&v->dev,
> + "Failed to allocate domain, device is not IOMMU cache coherent capable\n");
> return -ENOTSUPP;
> + }
>
> v->domain = iommu_domain_alloc(bus);
> if (!v->domain)
> --
> 2.34.1
>
