Re: [Qemu-devel] [PATCH 1/2] configure: Check if we can use ibv_reg_mr_iova

[Marcel Apfelbaum]

On 8/18/19 4:21 PM, Yuval Shaia wrote:
> The function reg_mr_iova is an enhanced version of ibv_reg_mr function
> that can help to easly register and use guest's MRs.
>
> Add check in 'configure' phase to detect if we have libibverbs with this
> support.
>
> Signed-off-by: Yuval Shaia <address@hidden>
> ---
>   configure | 28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
>
> diff --git a/configure b/configure
> index 714e7fb6a1..e8e4a57b6f 100755
> --- a/configure
> +++ b/configure
> @@ -3205,6 +3205,34 @@ else
>       pvrdma="no"
>   fi
>   
> +# Let's see if enhanced reg_mr is supported
> +if test "$pvrdma" = "yes" ; then
> +
> +cat > $TMPC <<EOF &&
> +#include <infiniband/verbs.h>
> +
> +int
> +main(void)
> +{
> +    struct ibv_mr *mr;
> +    struct ibv_pd *pd = NULL;
> +    size_t length = 10;
> +    uint64_t iova = 0;
> +    int access = 0;
> +    void *addr = NULL;
> +
> +    mr = ibv_reg_mr_iova(pd, addr, length, iova, access);

Here you check if the API is changed, right?
Can you query for a library version instead?

Thanks,
Marcel

> +
> +    ibv_dereg_mr(mr);
> +
> +    return 0;
> +}
> +EOF
> +    if ! compile_prog "" "-libverbs"; then
> +        QEMU_CFLAGS="$QEMU_CFLAGS -DLEGACY_RDMA_REG_MR"
> +    fi
> +fi
> +
>   ##########################################
>   # VNC SASL detection
>   if test "$vnc" = "yes" && test "$vnc_sasl" != "no" ; then