Re: [PATCH 09/10] xen/arm: parse `xen,static-mem` info during domain construction

[Julien Grall <julien@xxxxxxx>]

Hi Penny,

On 18/05/2021 06:21, Penny Zheng wrote:
> This commit parses `xen,static-mem` device tree property, to acquire
> static memory info reserved for this domain, when constructing domain
> during boot-up.
>
> Related info shall be stored in new static_mem value under per domain
> struct arch_domain.
So far, this seems to only be used during boot. So can't this be kept in 
the kinfo structure?
> Right now, the implementation of allocate_static_memory is missing, and
> will be introduced later. It just BUG() out at the moment.
>
> Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
> ---
>   xen/arch/arm/domain_build.c  | 58 ++++++++++++++++++++++++++++++++----
>   xen/include/asm-arm/domain.h |  3 ++
>   2 files changed, 56 insertions(+), 5 deletions(-)
>
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 282416e74d..30b55588b7 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -2424,17 +2424,61 @@ static int __init construct_domU(struct domain *d,
>   {
>       struct kernel_info kinfo = {};
>       int rc;
> -    u64 mem;
> +    u64 mem, static_mem_size = 0;
> +    const struct dt_property *prop;
> +    u32 static_mem_len;
> +    bool static_mem = false;
> +
> +    /*
> +     * Guest RAM could be of static memory from static allocation,
> +     * which will be specified through "xen,static-mem" property.
> +     */
> +    prop = dt_find_property(node, "xen,static-mem", &static_mem_len);
> +    if ( prop )
> +    {
> +        const __be32 *cell;
> +        u32 addr_cells = 2, size_cells = 2, reg_cells;
> +        u64 start, size;
> +        int i, banks;
> +        static_mem = true;
> +
> +        dt_property_read_u32(node, "#address-cells", &addr_cells);
> +        dt_property_read_u32(node, "#size-cells", &size_cells);
> +        BUG_ON(size_cells > 2 || addr_cells > 2);
> +        reg_cells = addr_cells + size_cells;
> +
> +        cell = (const __be32 *)prop->value;
> +        banks = static_mem_len / (reg_cells * sizeof (u32));
> +        BUG_ON(banks > NR_MEM_BANKS);
> +
> +        for ( i = 0; i < banks; i++ )
> +        {
> +            device_tree_get_reg(&cell, addr_cells, size_cells, &start, &size);
> +            d->arch.static_mem.bank[i].start = start;
> +            d->arch.static_mem.bank[i].size = size;
> +            static_mem_size += size;
> +
> +            printk(XENLOG_INFO
> +                    "Static Memory Bank[%d] for Domain %pd:"
> +                    "0x%"PRIx64"-0x%"PRIx64"\n",
> +                    i, d,
> +                    d->arch.static_mem.bank[i].start,
> +                    d->arch.static_mem.bank[i].start +
> +                    d->arch.static_mem.bank[i].size);
> +        }
> +        d->arch.static_mem.nr_banks = banks;
> +    }
Could we allocate the memory as we parse?

>   
>       rc = dt_property_read_u64(node, "memory", &mem);
> -    if ( !rc )
> +    if ( !static_mem && !rc )
>       {
>           printk("Error building DomU: cannot read \"memory\" property\n");
>           return -EINVAL;
>       }
> -    kinfo.unassigned_mem = (paddr_t)mem * SZ_1K;
> +    kinfo.unassigned_mem = static_mem ? static_mem_size : (paddr_t)mem * SZ_1K;
>   
> -    printk("*** LOADING DOMU cpus=%u memory=%"PRIx64"KB ***\n", d->max_vcpus, mem);
> +    printk("*** LOADING DOMU cpus=%u memory=%"PRIx64"KB ***\n",
> +            d->max_vcpus, (kinfo.unassigned_mem) >> 10);
>   
>       kinfo.vpl011 = dt_property_read_bool(node, "vpl011");
>   
> @@ -2452,7 +2496,11 @@ static int __init construct_domU(struct domain *d,
>       /* type must be set before allocate memory */
>       d->arch.type = kinfo.type;
>   #endif
> -    allocate_memory(d, &kinfo);
> +    if ( static_mem )
> +        /* allocate_static_memory(d, &kinfo); */
> +        BUG();
> +    else
> +        allocate_memory(d, &kinfo);
>   
>       rc = prepare_dtb_domU(d, &kinfo);
>       if ( rc < 0 )
> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> index c9277b5c6d..81b8eb453c 100644
> --- a/xen/include/asm-arm/domain.h
> +++ b/xen/include/asm-arm/domain.h
> @@ -10,6 +10,7 @@
>   #include <asm/gic.h>
>   #include <asm/vgic.h>
>   #include <asm/vpl011.h>
> +#include <asm/setup.h>
>   #include <public/hvm/params.h>
>   
>   struct hvm_domain
> @@ -89,6 +90,8 @@ struct arch_domain
>   #ifdef CONFIG_TEE
>       void *tee;
>   #endif
> +
> +    struct meminfo static_mem;
>   }  __cacheline_aligned;
>   
>   struct arch_vcpu
Cheers,

--
Julien Grall