Re: [PATCH v3 6/7] s390x/mmu: DAT table definition overhaul

[David Hildenbrand <david@redhat.com>]

On 01.10.19 06:54, Thomas Huth wrote:
> On 27/09/2019 11.58, David Hildenbrand wrote:
>> Let's use consitent names for the region/section/page table entries and
>> for the macros to extract relevant parts from virtual address. Make them
>> match the definitions in the PoP - e.g., how the relevant bits are actually
>> called.
>>
>> Introduce defines for all bits declared in the PoP. This will come in
>> handy in follow-up patches.
>>
>> Add a note where additional information about s390x and the used
>> definitions can be found.
>>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>> ---
>>  target/s390x/cpu.h        | 81 +++++++++++++++++++++++++++++----------
>>  target/s390x/mem_helper.c | 12 +++---
>>  target/s390x/mmu_helper.c | 37 ++++++++++--------
>>  3 files changed, 87 insertions(+), 43 deletions(-)
>>
>> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
>> index 163dae13d7..690b94c8ea 100644
>> --- a/target/s390x/cpu.h
>> +++ b/target/s390x/cpu.h
>> @@ -1,6 +1,10 @@
>>  /*
>>   * S/390 virtual CPU header
>>   *
>> + * For details on the s390x architecture and used definitions (e.g.,
>> + * PSW, PER and DAT (Dynamic Address Translation)), please refer to
>> + * the "z/Architecture Principles of Operations" - a.k.a. PoP.
>> + *
>>   *  Copyright (c) 2009 Ulrich Hecht
>>   *  Copyright IBM Corp. 2012, 2018
>>   *
>> @@ -558,26 +562,63 @@ QEMU_BUILD_BUG_ON(sizeof(SysIB) != 4096);
>>  #define ASCE_TYPE_SEGMENT     0x00        /* segment table type               */
>>  #define ASCE_TABLE_LENGTH     0x03        /* region table length              */
>>  
>> -#define REGION_ENTRY_ORIGIN   (~0xfffULL) /* region/segment table origin    */
>> -#define REGION_ENTRY_RO       0x200       /* region/segment protection bit  */
>> -#define REGION_ENTRY_TF       0xc0        /* region/segment table offset    */
>> -#define REGION_ENTRY_INV      0x20        /* invalid region table entry     */
>> -#define REGION_ENTRY_TYPE_MASK 0x0c       /* region/segment table type mask */
>> -#define REGION_ENTRY_TYPE_R1  0x0c        /* region first table type        */
>> -#define REGION_ENTRY_TYPE_R2  0x08        /* region second table type       */
>> -#define REGION_ENTRY_TYPE_R3  0x04        /* region third table type        */
>> -#define REGION_ENTRY_LENGTH   0x03        /* region third length            */
>> -
>> -#define SEGMENT_ENTRY_ORIGIN  (~0x7ffULL) /* segment table origin        */
>> -#define SEGMENT_ENTRY_FC      0x400       /* format control              */
>> -#define SEGMENT_ENTRY_RO      0x200       /* page protection bit         */
>> -#define SEGMENT_ENTRY_INV     0x20        /* invalid segment table entry */
>> -
>> -#define VADDR_PX              0xff000     /* page index bits   */
>> -
>> -#define PAGE_RO               0x200       /* HW read-only bit  */
>> -#define PAGE_INVALID          0x400       /* HW invalid bit    */
>> -#define PAGE_RES0             0x800       /* bit must be zero  */
>> +#define REGION_ENTRY_ORIGIN         0xfffffffffffff000ULL
>> +#define REGION_ENTRY_P              0x0000000000000200ULL
>> +#define REGION_ENTRY_TF             0x00000000000000c0ULL
>> +#define REGION_ENTRY_I              0x0000000000000020ULL
>> +#define REGION_ENTRY_TT             0x000000000000000cULL
>> +#define REGION_ENTRY_TL             0x0000000000000003ULL
>> +
>> +#define REGION_ENTRY_TT_REGION1     0x000000000000000cULL
>> +#define REGION_ENTRY_TT_REGION2     0x0000000000000008ULL
>> +#define REGION_ENTRY_TT_REGION3     0x0000000000000004ULL
>> +
>> +#define REGION3_ENTRY_RFAA          0xffffffff80000000ULL
>> +#define REGION3_ENTRY_AV            0x0000000000010000ULL
>> +#define REGION3_ENTRY_ACC           0x000000000000f000ULL
>> +#define REGION3_ENTRY_F             0x0000000000000800ULL
>> +#define REGION3_ENTRY_FC            0x0000000000000400ULL
>> +#define REGION3_ENTRY_IEP           0x0000000000000100ULL
>> +#define REGION3_ENTRY_CR            0x0000000000000010ULL
>> +
>> +#define SEGMENT_ENTRY_ORIGIN        0xfffffffffffff800ULL
>> +#define SEGMENT_ENTRY_SFAA          0xfffffffffff80000ULL
> 
> I think SFAA should be 0xfffffffffff00000ULL instead?

Indeed, very true. I think I finallz have to add EDAT-1/EDAT-2 support,
so I can test these code paths :)

> 
>> +#define SEGMENT_ENTRY_AV            0x0000000000010000ULL
>> +#define SEGMENT_ENTRY_ACC           0x000000000000f000ULL
>> +#define SEGMENT_ENTRY_F             0x0000000000000800ULL
>> +#define SEGMENT_ENTRY_FC            0x0000000000000400ULL
>> +#define SEGMENT_ENTRY_P             0x0000000000000200ULL
>> +#define SEGMENT_ENTRY_IEP           0x0000000000000100ULL
>> +#define SEGMENT_ENTRY_I             0x0000000000000020ULL
>> +#define SEGMENT_ENTRY_CS            0x0000000000000010ULL
>> +#define SEGMENT_ENTRY_TT            0x000000000000000cULL
>> +
>> +#define SEGMENT_ENTRY_TT_REGION1    0x000000000000000cULL
>> +#define SEGMENT_ENTRY_TT_REGION2    0x0000000000000008ULL
>> +#define SEGMENT_ENTRY_TT_REGION3    0x0000000000000004ULL
> 
> The above three definitions do not make much sense. TT should always be
> 00 for segment table entries.

Right, I thought I would use them for error checking, but

(entry & SEGMENT_ENTRY_TT) != SEGMENT_ENTRY_TT_SEGMENT

Is enough. Will drop, thanks!

-- 

Thanks,

David / dhildenb