Re: [dpdk-dev] [PATCH v4] vfio: fix sPAPR IOMMU DMA window size

["Jonas Pfefferle1" <JPF@zurich.ibm.com>]

Hi Thomas,

Can you please apply this patch?

Thanks,
Jonas

Alexey Kardashevskiy <aik@ozlabs.ru> wrote on 08/10/2017 08:03:17 AM:

> From: Alexey Kardashevskiy <aik@ozlabs.ru>
> To: Jonas Pfefferle <jpf@zurich.ibm.com>, anatoly.burakov@intel.com
> Cc: dev@dpdk.org
> Date: 08/10/2017 08:03 AM
> Subject: Re: [PATCH v4] vfio: fix sPAPR IOMMU DMA window size
>
> On 08/08/17 21:16, Jonas Pfefferle wrote:
> > DMA window size needs to be big enough to span all memory segment's
> > physical addresses. We do not need multiple levels of IOMMU tables
> > as we already span ~70TB of physical memory with 16MB hugepages.
> >
> > Signed-off-by: Jonas Pfefferle <jpf@zurich.ibm.com>
>
>
> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>
>
>
> > ---
> > v2:
> > * roundup to next power 2 function without loop.
> >
> > v3:
> > * Replace roundup_next_pow2 with rte_align64pow2
> >
> > v4:
> > * do not assume ordering of physical addresses of memsegs
> >
> >  lib/librte_eal/linuxapp/eal/eal_vfio.c | 20 +++++++++++++++++---
> >  1 file changed, 17 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/librte_eal/linuxapp/eal/eal_vfio.c b/lib/
> librte_eal/linuxapp/eal/eal_vfio.c
> > index 946df7e..7d5d61d 100644
> > --- a/lib/librte_eal/linuxapp/eal/eal_vfio.c
> > +++ b/lib/librte_eal/linuxapp/eal/eal_vfio.c
> > @@ -759,10 +759,19 @@ vfio_spapr_dma_map(int vfio_container_fd)
> >        return -1;
> >     }
> >
> > -   /* calculate window size based on number of hugepages configured */
> > -   create.window_size = rte_eal_get_physmem_size();
> > +   /* create DMA window from 0 to max(phys_addr + len) */
> > +   for (i = 0; i < RTE_MAX_MEMSEG; i++) {
> > +      if (ms[i].addr == NULL)
> > +         break;
> > +
> > +      create.window_size = RTE_MAX(create.window_size,
> > +            ms[i].phys_addr + ms[i].len);
> > +   }
> > +
> > +   /* sPAPR requires window size to be a power of 2 */
> > +   create.window_size = rte_align64pow2(create.window_size);
> >     create.page_shift = __builtin_ctzll(ms->hugepage_sz);
> > -   create.levels = 2;
> > +   create.levels = 1;
> >
> >     ret = ioctl(vfio_container_fd, VFIO_IOMMU_SPAPR_TCE_CREATE,
&create);
> >     if (ret) {
> > @@ -771,6 +780,11 @@ vfio_spapr_dma_map(int vfio_container_fd)
> >        return -1;
> >     }
> >
> > +   if (create.start_addr != 0) {
> > +      RTE_LOG(ERR, EAL, "  DMA window start address != 0\n");
> > +      return -1;
> > +   }
> > +
> >     /* map all DPDK segments for DMA. use 1:1 PA to IOVA mapping */
> >     for (i = 0; i < RTE_MAX_MEMSEG; i++) {
> >        struct vfio_iommu_type1_dma_map dma_map;
> >
>
>
> --
> Alexey
>