Re: [Xen-devel] [PATCH v02 2/7] arm: omap: introduce iommu translation for IPU remoteproc

[Julien Grall <julien.grall@xxxxxxxxxx>]

Hi Andrii,

On 26/06/14 12:07, Andrii Tseglytskyi wrote:
> +static u32 mmu_pte_table_alloc(struct mmu_info *mmu, u32 pgd, u32 sect_num,
> +                               struct mmu_pagetable *pgt, u32 hyp_addr)
> +{
> +    u32 *pte = NULL;
> +    u32 i;
> +
> +    /* allocate pte table once */
> +    if ( 0 == hyp_addr )
> +    {
> +        pte = xzalloc_bytes(PAGE_SIZE);
> +        if ( !pte )
> +        {
> +            pr_mmu("failed to alloc 2nd level table");
> +            return 0;
> +        }
> +    }
> +    else
> +    {
> +        pte = __va(hyp_addr & MMU_SECTION_MASK(mmu->pg_data->pte_shift));
> +    }
> +
> +    ASSERT(256 == MMU_PTRS_PER_PTE(mmu));
> +
> +    for ( i = 0; i < MMU_PTRS_PER_PTE(mmu); i++ )
> +    {
> +        u32 paddr, maddr;
> +
> +        paddr = pgd + (i * PAGE_SIZE);
> +        maddr = p2m_lookup(current->domain, paddr, NULL);
> +        ASSERT(maddr != INVALID_PADDR);
Hmmm, what prevents the guest to pass an invalid IPA? On debug build you 
will hit the assert, but on non-debug build you will screw the IPU page 
table.
[..]

> +static u32 mmu_ipu_translate_pagetable(struct mmu_info *mmu, struct 
> mmu_pagetable *pgt)
> +{
[..]

> +        /* first level pointers have different formats, depending on their 
> type */
> +        if ( ipu_pgd_is_super(pgd) )
> +            pd_mask = MMU_SECTION_MASK(MMU_OMAP_SUPER_SHIFT);
> +        else if ( ipu_pgd_is_section(pgd) )
> +            pd_mask = MMU_SECTION_MASK(MMU_OMAP_SECTION_SHIFT);
> +        else if ( ipu_pgd_is_table(pgd) )
> +            pd_mask = MMU_SECTION_MASK(MMU_OMAP_SECOND_LEVEL_SHIFT);
> +
> +        pd_paddr = pgd & pd_mask;
> +        pd_flags = pgd & ~pd_mask;
> +        pd_maddr = p2m_lookup(current->domain, pd_paddr, NULL);
> +        ASSERT(pd_maddr != INVALID_PADDR);
Same remark here.

--
Julien Grall

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