Re: [Qemu-devel] [RFC PATCH v3 13/18] spapr_pci: Enable DDW

[Alexey Kardashevskiy]

On 09/10/2014 11:01 PM, Alexander Graf wrote:
> 
> 
> On 29.08.14 12:12, Alexey Kardashevskiy wrote:
>> This implements DDW for emulated PHB.
>>
>> This advertises the query/create/remove RTAS tokens in device tree.
>> This does not advertise the reset RTAS token though, will be added later.
>>
>> The "ddw" property is enabled by default on a PHB but for compatibility
>> pseries-2.1 machine disables it.
>>
>> Since QEMU does not implement any 64bit DMA capable device, this hack
>> has been used to enable 64bit DMA on E1000:
>>
>> diff --git a/hw/net/e1000.c b/hw/net/e1000.c
>> index 0fc29a0..131f80a 100644
>> --- a/hw/net/e1000.c
>> +++ b/hw/net/e1000.c
>> @@ -240,6 +240,7 @@ static const uint32_t mac_reg_init[] = {
>>      [STATUS] =  0x80000000 | E1000_STATUS_GIO_MASTER_ENABLE |
>>                  E1000_STATUS_ASDV | E1000_STATUS_MTXCKOK |
>>                  E1000_STATUS_SPEED_1000 | E1000_STATUS_FD |
>> +                E1000_STATUS_PCIX_MODE |
>>                  E1000_STATUS_LU,
>>      [MANC] =    E1000_MANC_EN_MNG2HOST | E1000_MANC_RCV_TCO_EN |
>>                  E1000_MANC_ARP_EN | E1000_MANC_0298_EN |
>>
>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>> ---
>> Changes:
>> v3:
>> * removed reset
>> * windows_num is now 1 or bigger rather than 0-based value and it is only
>> changed in PHB code, not in RTAS
>> * added page mask check in create()
>>
>> v2:
>> * tested on hacked emulated E1000
>> * implemented DDW reset on the PHB reset
>> * spapr_pci_ddw_remove/spapr_pci_ddw_reset are public for reuse by VFIO
>> ---
>>  hw/ppc/spapr.c              |  9 +++++
>>  hw/ppc/spapr_pci.c          | 94 
>> +++++++++++++++++++++++++++++++++++++++++++++
>>  include/hw/pci-host/spapr.h |  7 ++++
>>  3 files changed, 110 insertions(+)
>>
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index d2d3c27..663cb75 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -1670,11 +1670,20 @@ static const TypeInfo spapr_machine_info = {
>>  static void spapr_machine_2_1_class_init(ObjectClass *oc, void *data)
>>  {
>>      MachineClass *mc = MACHINE_CLASS(oc);
>> +    static GlobalProperty compat_props[] = {
>> +        {
>> +            .driver   = TYPE_SPAPR_PCI_HOST_BRIDGE,
>> +            .property = "ddw",
>> +            .value    = stringify(off),
>> +        },
>> +        { /* end of list */ }
>> +    };
>>  
>>      mc->name = "pseries-2.1";
>>      mc->desc = "pSeries Logical Partition (PAPR compliant) v2.1";
>>      mc->alias = "pseries";
>>      mc->is_default = 1;
>> +    mc->compat_props = compat_props;
>>  }
>>  
>>  static const TypeInfo spapr_machine_2_1_info = {
>> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
>> index 2968b39..04ee1dc 100644
>> --- a/hw/ppc/spapr_pci.c
>> +++ b/hw/ppc/spapr_pci.c
>> @@ -470,6 +470,76 @@ static const MemoryRegionOps spapr_msi_ops = {
>>  };
>>  
>>  /*
>> + * Dynamic DMA windows
>> + */
>> +static int spapr_pci_ddw_query(sPAPRPHBState *sphb,
>> +                               uint32_t *windows_available,
>> +                               uint32_t *page_size_mask)
>> +{
>> +    *windows_available = 1;
>> +    *page_size_mask = DDW_PGSIZE_64K | DDW_PGSIZE_16M;
>> +
>> +    return 0;
> 
> What exactly does this return? The number of still available windows?
> The total number of windows?

1. Number of available windows
2. page masks supported for new windows.

This is what RTAS's counterpart does. We can change it to something better
if we want but I cannot think of anything better.



-- 
Alexey