[PATCH kernel] vfio/spapr: Add trace points for map/unmap

[Alexey Kardashevskiy]

On 27/10/17 14:00, Alexey Kardashevskiy wrote:
> This adds trace_map/trace_unmap tracepoints to spapr driver. Type1 already
> uses these via the IOMMU API (iommu_map/__iommu_unmap).
> 
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>

Ping?



> ---
> 
> Example:
>  qemu-system-ppc-8655  [096]   724.662740: unmap:                IOMMU: iova=0x000000003ffff000 size=4096 unmapped_size=4096
>  qemu-system-ppc-8656  [104]   724.970912: map:                  IOMMU: iova=0x0800000000000000 paddr=0x00007ffef7ff0000 size=65536
> ---
>  drivers/vfio/vfio_iommu_spapr_tce.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
> index 63112c36ab2d..4531486c77c6 100644
> --- a/drivers/vfio/vfio_iommu_spapr_tce.c
> +++ b/drivers/vfio/vfio_iommu_spapr_tce.c
> @@ -22,6 +22,7 @@
>  #include <linux/vmalloc.h>
>  #include <linux/sched/mm.h>
>  #include <linux/sched/signal.h>
> +#include <trace/events/iommu.h>
>  
>  #include <asm/iommu.h>
>  #include <asm/tce.h>
> @@ -502,17 +503,19 @@ static int tce_iommu_clear(struct tce_container *container,
>  		struct iommu_table *tbl,
>  		unsigned long entry, unsigned long pages)
>  {
> -	unsigned long oldhpa;
> +	unsigned long oldhpa, unmapped, firstentry = entry, totalpages = pages;
>  	long ret;
>  	enum dma_data_direction direction;
>  
> -	for ( ; pages; --pages, ++entry) {
> +	for (unmapped = 0; pages; --pages, ++entry) {
>  		direction = DMA_NONE;
>  		oldhpa = 0;
>  		ret = iommu_tce_xchg(tbl, entry, &oldhpa, &direction);
>  		if (ret)
>  			continue;
>  
> +		++unmapped;
> +
>  		if (direction == DMA_NONE)
>  			continue;
>  
> @@ -523,6 +526,9 @@ static int tce_iommu_clear(struct tce_container *container,
>  
>  		tce_iommu_unuse_page(container, oldhpa);
>  	}
> +	trace_unmap(firstentry << tbl->it_page_shift,
> +			totalpages << tbl->it_page_shift,
> +			unmapped << tbl->it_page_shift);
>  
>  	return 0;
>  }
> @@ -965,6 +971,8 @@ static long tce_iommu_ioctl(void *iommu_data,
>  					direction);
>  
>  		iommu_flush_tce(tbl);
> +		if (!ret)
> +			trace_map(param.iova, param.vaddr, param.size);
>  
>  		return ret;
>  	}
> 


-- 
Alexey