Re: [PATCH v5 2/7] xen/arm: implement domU extended regions

[Luca Fancellu <Luca.Fancellu@xxxxxxx>]

> On 29 Apr 2022, at 21:57, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> 
> From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
> 
> Implement extended regions for dom0less domUs. The implementation is
> based on the libxl implementation.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
> ---
> Changes in v5:
> - print the domain
> - coding style
> - simplify the code in find_domU_holes
> - return error if no regions allocated in find_domU_holes
> - use ROUNDUP
> - uint64_t/paddr_t
> ---
> xen/arch/arm/domain_build.c | 56 +++++++++++++++++++++++++++++++------
> 1 file changed, 48 insertions(+), 8 deletions(-)
> 
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 8be01678de..34d3e5ce30 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -1324,6 +1324,37 @@ out:
>     return res;
> }
> 
> +static int __init find_domU_holes(const struct kernel_info *kinfo,
> +                                  struct meminfo *ext_regions)
> +{
> +    unsigned int i;
> +    paddr_t bankend;
> +    const paddr_t bankbase[] = GUEST_RAM_BANK_BASES;
> +    const paddr_t banksize[] = GUEST_RAM_BANK_SIZES;
> +    int res = -ENOENT;
> +
> +    for ( i = 0; i < GUEST_RAM_BANKS; i++ )
> +    {
> +        struct membank *ext_bank = 
> &(ext_regions->bank[ext_regions->nr_banks]);
> +
> +        ext_bank->start = ROUNDUP(bankbase[i] + kinfo->mem.bank[i].size,
> +                                  SZ_2M);

NIT: there is no need anymore to break the line as SZ_2M will fit in the line 
length

> +
> +        bankend = ~0ULL >> (64 - p2m_ipa_bits);
> +        bankend = min(bankend, bankbase[i] + banksize[i] - 1);
> +        if ( bankend > ext_bank->start )
> +            ext_bank->size = bankend - ext_bank->start + 1;
> +
> +        /* 64MB is the minimum size of an extended region */
> +        if ( ext_bank->size < MB(64) )
> +            continue;
> +        ext_regions->nr_banks++;
> +        res = 0;
> +    }
> +
> +    return res;
> +}
> +
> static int __init make_hypervisor_node(struct domain *d,
>                                        const struct kernel_info *kinfo,
>                                        int addrcells, int sizecells)
> @@ -1360,12 +1391,13 @@ static int __init make_hypervisor_node(struct domain 
> *d,
> 
>     if ( !opt_ext_regions )
>     {
> -        printk(XENLOG_INFO "The extended regions support is disabled\n");
> +        printk(XENLOG_INFO "%pd: extended regions support is disabled\n", d);
>         nr_ext_regions = 0;
>     }
>     else if ( is_32bit_domain(d) )
>     {
> -        printk(XENLOG_WARNING "The extended regions are only supported for 
> 64-bit guest currently\n");
> +        printk(XENLOG_WARNING "%pd: extended regions are only supported for 
> 64-bit guest currently\n",
> +               d);

NIT: Something like that won’t exceed 80 chars:
        printk(XENLOG_WARNING
                  "%pd: extended regions not supported for 32-bit guests\n", d);


Reviewed-by: Luca Fancellu <luca.fancellu@xxxxxxx>