Re: [Qemu-devel] [PATCH v3 2/3] sPAPR: Support RTAS call ibm, {open, close}-errinjct

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/11/2015 10:57 AM, Gavin Shan wrote:
> On Mon, Aug 10, 2015 at 10:24:56PM +1000, David Gibson wrote:
>> On Fri, Aug 07, 2015 at 01:33:32PM +1000, Gavin Shan wrote:
>>> The patch supports RTAS calls "ibm,{open,close}-errinjct" to
>>> manupliate the token, which is passed to RTAS call "ibm,errinjct"
>>> to indicate the valid context for error injection. Each VM is
>>> permitted to have only one token at once and we simply have one
>>> random number for that.
>>>
>>> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>> ---
>>>   hw/ppc/spapr.c         |  5 ++++
>>>   hw/ppc/spapr_rtas.c    | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>>   include/hw/ppc/spapr.h | 10 +++++++-
>>>   3 files changed, 80 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>> index dfd808f..1ebd0b2 100644
>>> --- a/hw/ppc/spapr.c
>>> +++ b/hw/ppc/spapr.c
>>> @@ -1225,6 +1225,11 @@ static const VMStateDescription vmstate_spapr = {
>>>           VMSTATE_UINT64_TEST(rtc_offset, sPAPRMachineState, version_before_3),
>>>
>>>           VMSTATE_PPC_TIMEBASE_V(tb, sPAPRMachineState, 2),
>>> +
>>> +        /* Error injection token */
>>> +        VMSTATE_BOOL(is_errinjct_opened, sPAPRMachineState),
>>> +        VMSTATE_UINT32(errinjct_next_token, sPAPRMachineState),
>>
>> Because you're adding fields to the vmstate you'll need to define a
>> new version number and make these fields only considered in the new
>> version.
>>
>
> Agree, do we have an example for me to refer to?


Technically it is enough to send a token which is "not opened" when it is 
zero. The chunk below demonstrates versions use.

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index e046265..e568d41 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1213,17 +1213,21 @@ static bool version_before_3(void *opaque, int 
version_id)

  static const VMStateDescription vmstate_spapr = {
      .name = "spapr",
-    .version_id = 3,
+    .version_id = 4,
      .minimum_version_id = 1,
      .post_load = spapr_post_load,
      .fields = (VMStateField[]) {
          /* used to be @next_irq */
          VMSTATE_UNUSED_BUFFER(version_before_3, 0, 4),

+
          /* RTC offset */
          VMSTATE_UINT64_TEST(rtc_offset, sPAPRMachineState, version_before_3),

          VMSTATE_PPC_TIMEBASE_V(tb, sPAPRMachineState, 2),
+
+        /* Error injection token */
+        VMSTATE_UINT32_V(errinjct_next_token, sPAPRMachineState, 4),
          VMSTATE_END_OF_LIST()
      },
  };



>> Technically you only need to transfer whether the token is open, and
>> *if* it is open the current token value.  Not sure if it's worth
>> restricting to that though.
>>
>
> It would be fine to transfer the token even it's closed, I think.






-- 
Alexey