Re: [Qemu-devel] [RFC PATCH] powerpc: add PVR mask support

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 08/15/2013 03:21 PM, Alexander Graf wrote:
> 
> 
> Am 15.08.2013 um 05:35 schrieb Alexey Kardashevskiy <aik@ozlabs.ru>:
> 
>> IBM POWERPC processors encode PVR as a CPU family in higher 16 bits and
>> a CPU version in lower 16 bits. Since there is no significant change
>> in behavior between versions, there is no point to add every single CPU
>> version in QEMU's CPU list. Also, new CPU versions of already supported
>> CPU won't break the existing code.
>>
>> This adds a PVR mask support. POWER7, POWER7+ and POWER8 CPUs
>> definitions converted to use masks.
> 
> How does the user select that he wants a v2.3 p7 cpu with this patch?

Why would he want that? The behaviour would not change because of the
version - all definitions use the same POWERPC_FAMILY(POWER7) and PVR is
not virtualized anyway.

May be (may be) ppc_cpu_class_by_name() needs to be fixed to try to find
the PPC CPU class with the biggest mask to choose (for example)
004a0201/ffffffff rather than more common 004a0000/ffff0000 (if 004a0201 is
added to the list separately from the common definition for some reason).

btw the patch is incomplete - aliases should be removed too.



> 
> Alex
> 
>>
>> Cc: Andreas Färber <afaerber@suse.de>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>>
>> The patch does basically what the kernel does in arch/powerpc/kernel/cputable.c.
>>
>> ---
>> target-ppc/cpu-models.c     | 26 +++++++++++++++-----------
>> target-ppc/cpu-models.h     | 12 +++++++-----
>> target-ppc/cpu-qom.h        |  1 +
>> target-ppc/translate_init.c |  2 +-
>> 4 files changed, 24 insertions(+), 17 deletions(-)
>>
>> diff --git a/target-ppc/cpu-models.c b/target-ppc/cpu-models.c
>> index 8dea560..c40cf04 100644
>> --- a/target-ppc/cpu-models.c
>> +++ b/target-ppc/cpu-models.c
>> @@ -35,7 +35,7 @@
>> /* PowerPC CPU definitions                                                 */
>> #define POWERPC_DEF_PREFIX(pvr, svr, type)                                  \
>>     glue(glue(glue(glue(pvr, _), svr), _), type)
>> -#define POWERPC_DEF_SVR(_name, _desc, _pvr, _svr, _type)                    \
>> +#define POWERPC_DEF_SVR_MASK(_name, _desc, _pvr, _pvr_mask, _svr, _type)    \
>>     static void                                                             \
>>     glue(POWERPC_DEF_PREFIX(_pvr, _svr, _type), _cpu_class_init)            \
>>     (ObjectClass *oc, void *data)                                           \
>> @@ -44,6 +44,7 @@
>>         PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);                       \
>>                                                                             \
>>         pcc->pvr          = _pvr;                                           \
>> +        pcc->pvr_mask     = _pvr_mask;                                      \
>>         pcc->svr          = _svr;                                           \
>>         dc->desc          = _desc;                                          \
>>     }                                                                       \
>> @@ -66,9 +67,16 @@
>>     type_init(                                                              \
>>         glue(POWERPC_DEF_PREFIX(_pvr, _svr, _type), _cpu_register_types))
>>
>> +#define POWERPC_DEF_SVR(_name, _desc, _pvr, _svr, _type)                    \
>> +    POWERPC_DEF_SVR_MASK(_name, _desc, _pvr, CPU_POWERPC_DEFAULT_MASK,      \
>> +                         _svr, _type)
>> +
>> #define POWERPC_DEF(_name, _pvr, _type, _desc)                              \
>>     POWERPC_DEF_SVR(_name, _desc, _pvr, POWERPC_SVR_NONE, _type)
>>
>> +#define POWERPC_DEF_MASK(_name, _pvr, _pvr_mask, _type, _desc)              \
>> +    POWERPC_DEF_SVR_MASK(_name, _desc, _pvr, _pvr_mask, POWERPC_SVR_NONE, _type)
>> +
>>     /* Embedded PowerPC                                                      */
>>     /* PowerPC 401 family                                                    */
>>     POWERPC_DEF("401",           CPU_POWERPC_401,                    401,
>> @@ -1133,16 +1141,12 @@
>>     POWERPC_DEF("POWER6A",       CPU_POWERPC_POWER6A,                POWER6,
>>                 "POWER6A")
>> #endif
>> -    POWERPC_DEF("POWER7_v2.0",   CPU_POWERPC_POWER7_v20,             POWER7,
>> -                "POWER7 v2.0")
>> -    POWERPC_DEF("POWER7_v2.1",   CPU_POWERPC_POWER7_v21,             POWER7,
>> -                "POWER7 v2.1")
>> -    POWERPC_DEF("POWER7_v2.3",   CPU_POWERPC_POWER7_v23,             POWER7,
>> -                "POWER7 v2.3")
>> -    POWERPC_DEF("POWER7+_v2.1",  CPU_POWERPC_POWER7P_v21,            POWER7,
>> -                "POWER7+ v2.1")
>> -    POWERPC_DEF("POWER8_v1.0",   CPU_POWERPC_POWER8_v10,             POWER8,
>> -                "POWER8 v1.0")
>> +    POWERPC_DEF_MASK("POWER7", CPU_POWERPC_POWER7, CPU_POWERPC_POWER7_MASK,
>> +                     POWER7, "POWER7")
>> +    POWERPC_DEF_MASK("POWER7+", CPU_POWERPC_POWER7P, CPU_POWERPC_POWER7P_MASK,
>> +                     POWER7, "POWER7")
>> +    POWERPC_DEF_MASK("POWER8", CPU_POWERPC_POWER8, CPU_POWERPC_POWER8_MASK,
>> +                     POWER8, "POWER8")
>>     POWERPC_DEF("970",           CPU_POWERPC_970,                    970,
>>                 "PowerPC 970")
>>     POWERPC_DEF("970fx_v1.0",    CPU_POWERPC_970FX_v10,              970FX,
>> diff --git a/target-ppc/cpu-models.h b/target-ppc/cpu-models.h
>> index d9145d1..b322063 100644
>> --- a/target-ppc/cpu-models.h
>> +++ b/target-ppc/cpu-models.h
>> @@ -39,6 +39,7 @@ extern PowerPCCPUAlias ppc_cpu_aliases[];
>> /*****************************************************************************/
>> /* PVR definitions for most known PowerPC                                    */
>> enum {
>> +    CPU_POWERPC_DEFAULT_MASK       = 0xFFFFFFFF,
>>     /* PowerPC 401 family */
>>     /* Generic PowerPC 401 */
>> #define CPU_POWERPC_401              CPU_POWERPC_401G2
>> @@ -552,11 +553,12 @@ enum {
>>     CPU_POWERPC_POWER6             = 0x003E0000,
>>     CPU_POWERPC_POWER6_5           = 0x0F000001, /* POWER6 in POWER5 mode */
>>     CPU_POWERPC_POWER6A            = 0x0F000002,
>> -    CPU_POWERPC_POWER7_v20         = 0x003F0200,
>> -    CPU_POWERPC_POWER7_v21         = 0x003F0201,
>> -    CPU_POWERPC_POWER7_v23         = 0x003F0203,
>> -    CPU_POWERPC_POWER7P_v21        = 0x004A0201,
>> -    CPU_POWERPC_POWER8_v10         = 0x004B0100,
>> +    CPU_POWERPC_POWER7             = 0x003F0000,
>> +    CPU_POWERPC_POWER7_MASK        = 0xFFFF0000,
>> +    CPU_POWERPC_POWER7P            = 0x004A0000,
>> +    CPU_POWERPC_POWER7P_MASK = 0xFFFF0000,
>> +    CPU_POWERPC_POWER8             = 0x004B0000,
>> +    CPU_POWERPC_POWER8_MASK        = 0xFFFF0000,
>>     CPU_POWERPC_970                = 0x00390202,
>>     CPU_POWERPC_970FX_v10          = 0x00391100,
>>     CPU_POWERPC_970FX_v20          = 0x003C0200,
>> diff --git a/target-ppc/cpu-qom.h b/target-ppc/cpu-qom.h
>> index f3c710a..0ae8b09 100644
>> --- a/target-ppc/cpu-qom.h
>> +++ b/target-ppc/cpu-qom.h
>> @@ -54,6 +54,7 @@ typedef struct PowerPCCPUClass {
>>     void (*parent_reset)(CPUState *cpu);
>>
>>     uint32_t pvr;
>> +    uint32_t pvr_mask;
>>     uint32_t svr;
>>     uint64_t insns_flags;
>>     uint64_t insns_flags2;
>> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
>> index 13b290c..01dffa6 100644
>> --- a/target-ppc/translate_init.c
>> +++ b/target-ppc/translate_init.c
>> @@ -8161,7 +8161,7 @@ static gint ppc_cpu_compare_class_pvr(gconstpointer a, gconstpointer b)
>>     }
>> #endif
>>
>> -    return pcc->pvr == pvr ? 0 : -1;
>> +    return pcc->pvr == (pvr & pcc->pvr_mask) ? 0 : -1;
>> }
>>
>> PowerPCCPUClass *ppc_cpu_class_by_pvr(uint32_t pvr)
>> -- 
>> 1.8.3.2
>>


-- 
Alexey