Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 1/4] target-ppc: Extend rtas-blob

[Alexander Graf]

On 05.11.14 09:46, Aravinda Prasad wrote:
> 
> 
> On Wednesday 05 November 2014 01:41 PM, Alexander Graf wrote:
>>
>>
>> On 05.11.14 08:12, Aravinda Prasad wrote:
>>> Extend rtas-blob to accommodate error log. Error log
>>> structure is saved in rtas space upon a machine check
>>> exception.
>>>
>>> Signed-off-by: Aravinda Prasad <address@hidden>
>>> ---
>>>  hw/ppc/spapr.c         |    7 +++++++
>>>  include/hw/ppc/spapr.h |    5 +++++
>>>  2 files changed, 12 insertions(+)
>>>
>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>> index 30de25d..38e26af 100644
>>> --- a/hw/ppc/spapr.c
>>> +++ b/hw/ppc/spapr.c
>>> @@ -1431,6 +1431,13 @@ static void ppc_spapr_init(MachineState *machine)
>>>  
>>>      filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, "spapr-rtas.bin");
>>>      spapr->rtas_size = get_image_size(filename);
>>> +
>>> +    /*
>>> +     * Resize blob to accommodate error log. The layout of the rtas
>>> +     * blob is defined in include/hw/ppc/spapr.h
>>> +     */
>>> +    spapr->rtas_size = TARGET_PAGE_ALIGN(spapr->rtas_size);
>>
>> How big is the error log? You could just extend the RTAS blob to include
>> space for it if it's not too big.
> 
> Error log is around 10 bytes and requires additional 24 bytes to store
> saved sro/srr1.
> 
> Hmm.. yes it can be included in RTAS blob itself.
> 
> 
>>
>>> +
>>>      spapr->rtas_blob = g_malloc(spapr->rtas_size);
>>>      if (load_image_size(filename, spapr->rtas_blob, spapr->rtas_size) < 0) 
>>> {
>>>          hw_error("qemu: could not load LPAR rtas '%s'\n", filename);
>>> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
>>> index 749daf4..d08fcc2 100644
>>> --- a/include/hw/ppc/spapr.h
>>> +++ b/include/hw/ppc/spapr.h
>>> @@ -480,4 +480,9 @@ int spapr_dma_dt(void *fdt, int node_off, const char 
>>> *propname,
>>>  int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
>>>                        sPAPRTCETable *tcet);
>>>  
>>> +/* RTAS Blob layout in memory */
>>> +#define RTAS_ENTRY_OFFSET        0
>>> +#define RTAS_TRAMPOLINE_OFFSET   0x200
>>> +#define RTAS_ERRLOG_OFFSET       0x800
>>
>> I thought we agreed that these offsets should've been defined by the
>> blob itself?
>>
> 
> I think I got it wrong.
> 
> I will include these indexes at the entry of RTAS blob. With that we
> will have something like this:
> 
> RTAS_ENTRY_OFFSET  =      *(spapr->rtas_addr)
> RTAS_TRAMPOLINE_OFFSET =  *(spapr->rtas_addr+8)
> RTAS_ERRLOG_OFFSET =      *(spapr->rtas_addr+16)
> 
> I will fix this.

Cool :). Just store the offsets inside of a helper struct that you for
example store in the spapr struct, then we don't need to read volatile
guest memory for the offsets.


Alex