Re: [Qemu-devel] [PATCH v2 8/9] spapr_iommu: Introduce page_shift in sPAPRTCETable

[Alexander Graf <agraf@suse.de>]

On 22.05.14 13:19, Alexey Kardashevskiy wrote:
> At the moment only 4K pages are supported by sPAPRTCETable. Since sPAPR
> spec allows other page sizes and we are going to implement them, we need
> page size to be configrable.
>
> This adds @page_shift into sPAPRTCETable and replaces SPAPR_TCE_PAGE_SHIFT
> with it whereever it is possible.
>
> This removes SPAPR_TCE_PAGE_MASK as it is no longer used.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
> Changes:
> v2:
> * target_ulong for "mask" replaced with hwaddr
> * added page_mask and page_size local variables where possible
> ---
>   hw/ppc/spapr_iommu.c   | 66 +++++++++++++++++++++++++++++++-------------------
>   hw/ppc/spapr_pci.c     |  1 +
>   hw/ppc/spapr_vio.c     |  1 +
>   include/hw/ppc/spapr.h |  3 ++-
>   4 files changed, 45 insertions(+), 26 deletions(-)
>
> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
> index 99d1d6e..65f9a89 100644
> --- a/hw/ppc/spapr_iommu.c
> +++ b/hw/ppc/spapr_iommu.c
> @@ -70,12 +70,14 @@ static IOMMUTLBEntry spapr_tce_translate_iommu(MemoryRegion *iommu, hwaddr addr)
>   
>       if (tcet->bypass) {
>           ret.perm = IOMMU_RW;
> -    } else if ((addr >> SPAPR_TCE_PAGE_SHIFT) < tcet->nb_table) {
> +    } else if ((addr >> tcet->page_shift) < tcet->nb_table) {
>           /* Check if we are in bound */
> -        tce = tcet->table[addr >> SPAPR_TCE_PAGE_SHIFT];
> -        ret.iova = addr & ~SPAPR_TCE_PAGE_MASK;
> -        ret.translated_addr = tce & ~SPAPR_TCE_PAGE_MASK;
> -        ret.addr_mask = SPAPR_TCE_PAGE_MASK;
> +        hwaddr page_mask = ~((1 << tcet->page_shift) - 1);
1ULL

> +
> +        tce = tcet->table[addr >> tcet->page_shift];
> +        ret.iova = addr & page_mask;
> +        ret.translated_addr = tce & page_mask;
> +        ret.addr_mask = ~page_mask;
>           ret.perm = tce;
>       }
>       trace_spapr_iommu_xlate(tcet->liobn, addr, ret.iova, ret.perm,
> @@ -113,7 +115,7 @@ static int spapr_tce_table_realize(DeviceState *dev)
>       if (kvm_enabled()) {
>           tcet->table = kvmppc_create_spapr_tce(tcet->liobn,
>                                                 tcet->nb_table <<
> -                                              SPAPR_TCE_PAGE_SHIFT,
> +                                              tcet->page_shift,
>                                                 &tcet->fd);
>       }
>   
> @@ -133,6 +135,7 @@ static int spapr_tce_table_realize(DeviceState *dev)
>   }
>   
>   sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
> +                                   uint32_t page_shift,
>                                      uint32_t nb_table)
>   {
>       sPAPRTCETable *tcet;
> @@ -149,6 +152,7 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn,
>   
>       tcet = SPAPR_TCE_TABLE(object_new(TYPE_SPAPR_TCE_TABLE));
>       tcet->liobn = liobn;
> +    tcet->page_shift = page_shift;
>       tcet->nb_table = nb_table;
>   
>       object_property_add_child(OBJECT(owner), "tce-table", OBJECT(tcet), NULL);
> @@ -194,19 +198,20 @@ static target_ulong put_tce_emu(sPAPRTCETable *tcet, target_ulong ioba,
>                                   target_ulong tce)
>   {
>       IOMMUTLBEntry entry;
> +    hwaddr page_mask = ~((1 << tcet->page_shift) - 1);

...


Alex