Re: [PATCH 1/3] vhost: fix build for powerpc

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 8/31/23 14:10, Bruce Richardson wrote:
> When building on Ubuntu using the packaged powerpc compiler[1], a
> warning is issued about the print format of the __u64 values.
> 
> ../../lib/vhost/vduse.c: In function ‘vduse_vring_setup’:
> ../../lib/vhost/vhost.h:676:17: error: format ‘%llx’ expects argument of
> type ‘long long unsigned int’, but argument 5 has type ‘__u64’ {aka
> ‘long unsigned int’} [-Werror=format=]
>    676 |                 "VHOST_CONFIG: (%s) " fmt, prefix, ##args)
>        |                 ^~~~~~~~~~~~~~~~~~~~~
> 
> Changing the format specifier to %lx, or to use PRIx64 breaks other
> builds, so the safest solution is to explicitly typecast the printed
> values to match the format string.
> 
> [1] powerpc64le-linux-gnu-gcc (Ubuntu 12.3.0-1ubuntu1~23.04) 12.3.0
> 
> Fixes: a9120db8b98b ("vhost: add VDUSE device startup")
> Cc: maxime.coquelin@redhat.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>   lib/vhost/vduse.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
> index 73ed424232..e2b6d35d37 100644
> --- a/lib/vhost/vduse.c
> +++ b/lib/vhost/vduse.c
> @@ -162,9 +162,12 @@ vduse_vring_setup(struct virtio_net *dev, unsigned int index)
>   
>   	VHOST_LOG_CONFIG(dev->ifname, INFO, "VQ %u info:\n", index);
>   	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tnum: %u\n", vq_info.num);
> -	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdesc_addr: %llx\n", vq_info.desc_addr);
> -	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdriver_addr: %llx\n", vq_info.driver_addr);
> -	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdevice_addr: %llx\n", vq_info.device_addr);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdesc_addr: %llx\n",
> +			(unsigned long long)vq_info.desc_addr);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdriver_addr: %llx\n",
> +			(unsigned long long)vq_info.driver_addr);
> +	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tdevice_addr: %llx\n",
> +			(unsigned long long)vq_info.device_addr);
>   	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tavail_idx: %u\n", vq_info.split.avail_index);
>   	VHOST_LOG_CONFIG(dev->ifname, INFO, "\tready: %u\n", vq_info.ready);
>   

It is surprising PRIx64 does not work on other architectures.
I don't see a better solution, so:

Acked-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime