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

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

[Alexey Kardashevskiy]

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);
+    }
+
     /* We place the device tree and RTAS just below either the top of the RMA,
      * or just below 2GB, whichever is lowere, so that it can be
      * processed with 32-bit real mode code if necessary */
-- 
1.8.4.rc4

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

[Thomas Huth]

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

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

[Alexander Graf]

On 06.11.2013, at 12:13, Thomas Huth <thuth@linux.vnet.ibm.com> wrote:

> 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?

It should, yes. It was very wrong in that spot from the first place, as that helper really should only create the fdt entries, not modify global state.


Alex

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

[Alexander Graf]

On 06.11.2013, at 08:54, 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?

Just declare it as your own ;).


Alex