Re: [RFC v1 4/4] qemu: adjust queried bar size to power-of-2

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 6/6/23 01:50, ankita@nvidia.com wrote:
> From: Ankit Agrawal <ankita@nvidia.com>
> 
> The GPU device memory is reported to the VM as a BAR. The device memory
> may not be aligned to the power-of-2, but the QEMU expects the PCI BAR to
> be. Align the reported device memory size to the next power-of-2 before
> QEMU does an mmap.
> 
> Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
> ---
>   hw/vfio/common.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 4d01ea3515..bb49200458 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -2061,7 +2061,7 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
>   
>       region->vbasedev = vbasedev;
>       region->flags = info->flags;
> -    region->size = info->size;
> +    region->size = info->size ? pow2ceil(info->size) : info->size;

        region->size = [REAL_]HOST_PAGE_ALIGN(info->size)?

>       region->fd_offset = info->offset;
>       region->nr = index;
>