Re: [Qemu-devel] [PATCH v2] spapr: make sure RMA is in first mode of first memory node

[Thomas Huth <thuth@linux.vnet.ibm.com>]

On Wed,  6 Nov 2013 18:54:11 +1100
Alexey Kardashevskiy <aik@ozlabs.ru> wrote:

> The SPAPR specification says that the RMA starts at the LPAR's logical
> address 0 and is the first logical memory block reported in
> the LPAR’s device tree.
> 
> So SLOF only maps the first block and that block needs to span
> the full RMA.
> 
> This makes sure that the RMA area is where SLOF expects it.
> 
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
> 
> I came up with v1 of the patch but the actual code came from
> Alexander Graf. Who should I put as author of this?
> 
> ---
>  hw/ppc/spapr.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 57b38cf..57473df 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1114,6 +1114,7 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
>      MemoryRegion *sysmem = get_system_memory();
>      MemoryRegion *ram = g_new(MemoryRegion, 1);
>      hwaddr rma_alloc_size;
> +    hwaddr node0_size = (nb_numa_nodes > 1) ? node_mem[0] : ram_size;
>      uint32_t initrd_base = 0;
>      long kernel_size = 0, initrd_size = 0;
>      long load_limit, rtas_limit, fw_size;
> @@ -1138,7 +1139,7 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
>      if (rma_alloc_size && (rma_alloc_size < ram_size)) {
>          spapr->rma_size = rma_alloc_size;
>      } else {
> -        spapr->rma_size = ram_size;
> +        spapr->rma_size = node0_size;
> 
>          /* With KVM, we don't actually know whether KVM supports an
>           * unbounded RMA (PR KVM) or is limited by the hash table size
> @@ -1155,6 +1156,12 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
>          }
>      }
> 
> +    if (spapr->rma_size > node0_size) {
> +        fprintf(stderr, "Error: Numa node 0 has to span the RMA (%#08"HWADDR_PRIx")\n",
> +                spapr->rma_size);
> +        exit(1);
> +    }
> +

What about the "if (spapr->rma_size > node0_size)" at the beginning of
spapr_populate_memory()? Could/should that go away now?

 Thomas