Re: [PATCH v2 2/5] hw/nvme: use symbolic names for registers

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 7/14/21 12:12 AM, Philippe Mathieu-Daudé wrote:
> On 7/13/21 9:24 PM, Klaus Jensen wrote:
>> From: Klaus Jensen <k.jensen@samsung.com>
>>
>> Add the NvmeBarRegs enum and use these instead of explicit register
>> offsets.
>>
>> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
>> ---
>>  include/block/nvme.h | 27 +++++++++++++++++++++++++++
>>  hw/nvme/ctrl.c       | 44 ++++++++++++++++++++++----------------------
>>  2 files changed, 49 insertions(+), 22 deletions(-)
>>
>> diff --git a/include/block/nvme.h b/include/block/nvme.h
>> index 84053b68b987..082d4bddbf9f 100644
>> --- a/include/block/nvme.h
>> +++ b/include/block/nvme.h
>> @@ -31,6 +31,33 @@ typedef struct QEMU_PACKED NvmeBar {
>>      uint8_t     css[484];
>>  } NvmeBar;
>>  
>> +enum NvmeBarRegs {
>> +    NVME_REG_CAP     = 0x0,
>> +    NVME_REG_VS      = 0x8,
>> +    NVME_REG_INTMS   = 0xc,
>> +    NVME_REG_INTMC   = 0x10,
>> +    NVME_REG_CC      = 0x14,
>> +    NVME_REG_CSTS    = 0x1c,
>> +    NVME_REG_NSSR    = 0x20,
>> +    NVME_REG_AQA     = 0x24,
>> +    NVME_REG_ASQ     = 0x28,
>> +    NVME_REG_ACQ     = 0x30,
>> +    NVME_REG_CMBLOC  = 0x38,
>> +    NVME_REG_CMBSZ   = 0x3c,
>> +    NVME_REG_BPINFO  = 0x40,
>> +    NVME_REG_BPRSEL  = 0x44,
>> +    NVME_REG_BPMBL   = 0x48,
>> +    NVME_REG_CMBMSC  = 0x50,
>> +    NVME_REG_CMBSTS  = 0x58,
>> +    NVME_REG_PMRCAP  = 0xe00,
>> +    NVME_REG_PMRCTL  = 0xe04,
>> +    NVME_REG_PMRSTS  = 0xe08,
>> +    NVME_REG_PMREBS  = 0xe0c,
>> +    NVME_REG_PMRSWTP = 0xe10,
>> +    NVME_REG_PMRMSCL = 0xe14,
>> +    NVME_REG_PMRMSCU = 0xe18,
>> +};
>> +
>>  enum NvmeCapShift {
>>      CAP_MQES_SHIFT     = 0,
>>      CAP_CQR_SHIFT      = 16,
>> diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
>> index 28299c6f3764..8c305315f41c 100644
>> --- a/hw/nvme/ctrl.c
>> +++ b/hw/nvme/ctrl.c
>> @@ -5740,7 +5740,7 @@ static void nvme_write_bar(NvmeCtrl *n, hwaddr offset, uint64_t data,
>>      }
>>  
>>      switch (offset) {
>> -    case 0xc:   /* INTMS */
>> +    case NVME_REG_INTMS:
> 
> What about using offsetof(NvmeBar, intms) instead?

BTW I'm not suggesting this is better, I just wonder how we can avoid
to duplicate the definitions. Alternative is declaring:

enum NvmeBarRegs {
    NVME_REG_CAP     = offsetof(NvmeBar, cap),
    NVME_REG_VS      = offsetof(NvmeBar, vs),
    ...

Or keeping your patch.