On 03/04/2016 03:20 PM, Anshuman Khandual wrote:
> For partition running on PHYP, there can be a adjunct partition
> which shares the virtual address range with the operating system.
> Virtual address ranges which can be used by the adjunct partition
> are communicated with virtual device node of the device tree with
> a property known as "ibm,reserved-virtual-addresses". This patch
> introduces a new function named 'validate_reserved_va_range' which
> is called during initialization to validate that these reserved
> virtual address ranges do not overlap with the address ranges used
> by the kernel for all supported memory contexts. This helps prevent
> the possibility of getting return codes similar to H_RESOURCE for
> H_PROTECT hcalls for conflicting HPTE entries.
>
> Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com>
> ---
> - It has been tested on both LE and BE POWER8 platforms
>
> arch/powerpc/mm/hash_utils_64.c | 77
> +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 77 insertions(+)
>
> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
> index ba59d59..ee14df7 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -1564,3 +1564,80 @@ void setup_initial_memory_limit(phys_addr_t
> first_memblock_base,
> /* Finally limit subsequent allocations */
> memblock_set_current_limit(ppc64_rma_size);
> }
> +
> +/*
> + * PAPR says that each reserved virtual address range record
> + * contains three be32 elements which is of toal 12 bytes.
> + * First two be32 elements contain the abbreviated virtual
> + * address (high order 32 bits and low order 32 bits that
> + * generate the abbreviated virtual address of 64 bits which
> + * need to be concatenated with 24 bits of 0 at the end) and
> + * the third be32 element contains the size of the reserved
> + * virtual address range as number of consecutive 4K pages.
> + */
> +struct reserved_va_record {
> + __be32 high_addr;
> + __be32 low_addr;
> + __be32 nr_pages_4K;
> +};
> +
> +/*
> + * Linux uses 65 bits (CONTEXT_BITS + ESID_BITS + SID_SHIFT)
> + * of virtual address. As reserved virtual address comes in
> + * as an abbreviated form (64 bits) from the device tree, we
> + * will use a partial address bit mask (65 >> 24) to match it
> + * for simplicity.
> + */
> +#define RVA_LESS_BITS 24
> +#define LINUX_VA_BITS CONTEXT_BITS + ESID_BITS + SID_SHIFT
> +#define PARTIAL_LINUX_VA_MASK ((1ULL << (LINUX_VA_BITS -
> RVA_LESS_BITS)) - 1)
Oops, the indentation should have been similar here. Will fix it.
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