Controller register는 2장 내용중 PCI header 부분에서 나온 MLBAR/MUBAR (PCI BAR0, BAR1) register들을 통해 Host PC의 main memory 영역에 할당되어 있다. Host는 locked access를 할수 없다. 아래의 그림은 SSD controller에서 사용될 register들에 대한 정의이다.
nvme-cli가 설치되어 있다는 전제하에 실행
#nvme show-regs /dev/nvme0
또는
#nvme show-regs /dev/nvme0 -H2장에서처럼 마찬가지로 이번에는 controller의 register 값들을 보기 위해 nvme-cli 툴을 사용한다. nvme-cli는 nvme 디바이스에 대해 편리하게 사용하기 위한 commnad line 기반의 management tool이다.
nvme show-regs /dev/nvme0만 사용했을 경우엔 hex 값으로 값이 전부 보이며 -H 옵션을 주게 되면 human-readable 옵션으로 보기 좋게 바뀐다.
cap : 200a010fff
Controller Memory Buffer Supported (CMBS): The Controller Memory Buffer is Not Supported
Persistent Memory Region Supported (PMRS): The Persistent Memory Region is Not Supported
Memory Page Size Maximum (MPSMAX): 4096 bytes
Memory Page Size Minimum (MPSMIN): 4096 bytes
Boot Partition Support (BPS): No
Command Sets Supported (CSS): NVM command set is supported
NVM Subsystem Reset Supported (NSSRS): No
Doorbell Stride (DSTRD): 4 bytes
Timeout (TO): 5000 ms
Arbitration Mechanism Supported (AMS): Weighted Round Robin with Urgent Priority Class is not supported
Contiguous Queues Required (CQR): Yes
Maximum Queue Entries Supported (MQES): 4096
version : 10200
NVMe specification 1.2
cc : 460001
I/O Completion Queue Entry Size (IOCQES): 16 bytes
I/O Submission Queue Entry Size (IOSQES): 64 bytes
Shutdown Notification (SHN): No notification; no effect
Arbitration Mechanism Selected (AMS): Round Robin
Memory Page Size (MPS): 4096 bytes
I/O Command Sets Selected (CSS): NVM Command Set
Enable (EN): Yes
csts : 1
Processing Paused (PP): No
NVM Subsystem Reset Occurred (NSSRO): No
Shutdown Status (SHST): Normal operation (no shutdown has been requested)
Controller Fatal Status (CFS): False
Ready (RDY): Yes
nssr : 0
NVM Subsystem Reset Control (NSSRC): 0
intms : 0
Interrupt Vector Mask Set (IVMS): 0
intmc : 0
Interrupt Vector Mask Clear (IVMC): 0
aqa : 1f001f
Admin Completion Queue Size (ACQS): 32
Admin Submission Queue Size (ASQS): 32
asq : 303d9000
Admin Submission Queue Base (ASQB): 303d9000
acq : 34580000
Admin Completion Queue Base (ACQB): 34580000
cmbloc : 3
Offset (OFST): 0x0 (See cmbsz.szu for granularity)
CMB Queue Dword Alignment (CQDA): 0
CMB Data Metadata Mixed Memory Support (CDMMMS): Enforced
CMB Data Pointer and Command Independent Locations Support (CDPCILS): Enforced
CMB Data Pointer Mixed Locations Support (CDPMLS): Enforced
CMB Queue Physically Discontiguous Support (CQPDS): Enforced
CMB Queue Mixed Memory Support (CQMMS): Enforced
Base Indicator Register (BIR): 0x3
cmbsz : 500003
Size (SZ): 1280
Size Units (SZU): 4 KB
Write Data Support (WDS): Write Data and metadata transfer in Controller Memory Buffer is Not supported
Read Data Support (RDS): Read Data and metadata transfer in Controller Memory Buffer is Not supported
PRP SGL List Support (LISTS): PRP/SG Lists in Controller Memory Buffer is Not supported
Completion Queue Support (CQS): Admin and I/O Completion Queues in Controller Memory Buffer is Supported
Submission Queue Support (SQS): Admin and I/O Submission Queues in Controller Memory Buffer is Supported
bpinfo : ffffffff
Active Boot Partition ID (ABPID): 1
Boot Read Status (BRS): Error completing Boot Partition read
Boot Partition Size (BPSZ): 32767
bprsel : ffffffff
Boot Partition Identifier (BPID): 1
Boot Partition Read Offset (BPROF): fffff
Boot Partition Read Size (BPRSZ): 3ff
bpmbl : ffffffffffffffff
Boot Partition Memory Buffer Base Address (BMBBA): ffffffffffffffff
cmbmsc : ffffffffffffffff
Controller Base Address (CBA) : fffffffffffff
Controller Memory Space Enable (CMSE): 1
Capabilities Registers Enabled (CRE) : CMBLOC and CMBSZ registers are enabled
cmbsts : ffffffff
Controller Base Address Invalid (CBAI): 1
pmrcap : ffffffff
Controller Memory Space Supported (CMSS) : Referencing PMR with host supplied addresses is Supported
Persistent Memory Region Timeout (PMRTO): ff
Persistent Memory Region Write Barrier Mechanisms(PMRWBM): f
Persistent Memory Region Time Units (PMRTU): PMR time unit is minutes
Base Indicator Register (BIR): 7
Write Data Support (WDS): Write data to the PMR is supported
Read Data Support (RDS): Read data from the PMR is supported
pmrctl : ffffffff
Enable (EN): PMR is READY
pmrsts : ffffffff
Controller Base Address Invalid (CBAI): 1
Health Status (HSTS): Reserved
Not Ready (NRDY): The Persistent Memory Region is Not Ready to process PCI Express memory read and write requests
Error (ERR) : ff
pmrebs : ffffffff
PMR Elasticity Buffer Size Base (PMRWBZ): ffffff
Read Bypass Behavior : memory reads not conflicting with memory writes in the PMR Elasticity Buffer SHALL bypass those memory writes
PMR Elasticity Buffer Size Units (PMRSZU): Reserved
pmrswtp : ffffffff
PMR Sustained Write Throughput (PMRSWTV): ffffff
PMR Sustained Write Throughput Units (PMRSWTU): Reserved/second
pmrmsc : ffffffffffffffff
Controller Base Address (CBA) : fffffffffffff
Controller Memory Space Enable (CMSE : 0
위 결과는 -H 옵션을 주고 실행했을때의 결과이다.
- CAP -controller capabilities
- 8B의 크기를 가지고 있다.
- 값: 0x200a010fff
- controller의 특성을 host software에게 알려준다.
- nvme-cli에서는 admin passthru command를 통해 register 값을 읽어 온다.
- Controller Memory Buffer Supported (CMBS): The Controller Memory Buffer is Not Supported
- Persistent Memory Region Supported (PMRS): The Persistent Memory Region is Not Supported
- Memory Page Size Maximum (MPSMAX): 4096 bytes
- Memory Page Size Minimum (MPSMIN): 4096 bytes
- Boot Partition Support (BPS): No
- Command Sets Supported (CSS): NVM command set is supported
- NVM Subsystem Reset Supported (NSSRS): No
- Doorbell Stride (DSTRD): 4 bytes
- Timeout (TO): 5000 ms
- Arbitration Mechanism Supported (AMS): Weighted Round Robin with Urgent Priority Class is not supported
- Contiguous Queues Required (CQR): Yes
- Maximum Queue Entries Supported (MQES): 4096
- VS - version에 대한 것을 나타냄. 1.0 ~ 1.4까지 존재함.
- 4B를 가진다.
- 값: 0x10200
- NVMe specification 1.2
- intms - interrupt mask set
- 4B를 가진다.
- 값: 0 Interrupt Vector Mask Set (IVMS): 0
- intmc - interrupt mask clear
- 4B를 가진다.
- 값: 0 Interrupt Vector Mask Clear (IVMC): 0
- CC - controller configuration
- 해당 register는 controller를 위한 셋팅을 변경한다.
- Host가 가능한 부분
- Arbitraction mechanism (CC.AMS)
- Memory page size (CC.MPS)
- Command set (CC.CSS)
- cc : 460001
- I/O Completion Queue Entry Size (IOCQES): 16 bytes
- I/O Submission Queue Entry Size (IOSQES): 64 bytes
- Shutdown Notification (SHN): No notification; no effect
- Arbitration Mechanism Selected (AMS): Round Robin
- Memory Page Size (MPS): 4096 bytes
- I/O Command Sets Selected (CSS): NVM Command Set
- controller가 diable되었을대 (CC.EN == 0) 설정을 변경할 수 있다.
- Enable (EN): Yes
- NSSR - NVM subsystem reset
- NVM Subsystem Reset Control (NSSRC): 0
- CAP.NSSRS와 관련
- AQA - admin queue attributes
- 값: 1f001f
- Admin Completion Queue Size (ACQS): 32
- Admin Submission Queue Size (ASQS): 32
- asq : 303d9000
- Admin Submission Queue Base (ASQB): 303d9000
- acq : 34580000
- Admin Completion Queue Base (ACQB): 34580000
cmbloc : 3
Offset (OFST): 0x0
CMB Queue Dword Alignment (CQDA): 0
CMB Data Metadata Mixed Memory Support (CDMMMS): Enforced
CMB Data Pointer and Command Independent Locations Support (CDPCILS): Enforced
CMB Data Pointer Mixed Locations Support (CDPMLS): Enforced
CMB Queue Physically Discontiguous Support (CQPDS): Enforced
CMB Queue Mixed Memory Support (CQMMS): Enforced
Base Indicator Register (BIR): 0x3
cmbsz : 500003
Size (SZ): 1280
Size Units (SZU): 4 KB
Write Data Support (WDS): Write Data and metadata transfer in Controller Memory Buffer is Not supported
Read Data Support (RDS): Read Data and metadata transfer in Controller Memory Buffer is Not supported
PRP SGL List Support (LISTS): PRP/SG Lists in Controller Memory Buffer is Not supported
Completion Queue Support (CQS): Admin and I/O Completion Queues in Controller Memory Buffer is Supported
Submission Queue Support (SQS): Admin and I/O Submission Queues in Controller Memory Buffer is Supported
bpinfo : ffffffff
Active Boot Partition ID (ABPID): 1
Boot Read Status (BRS): Error completing Boot Partition read
Boot Partition Size (BPSZ): 32767
bprsel : ffffffff
Boot Partition Identifier (BPID): 1
Boot Partition Read Offset (BPROF): fffff
Boot Partition Read Size (BPRSZ): 3ff
bpmbl : ffffffffffffffff
Boot Partition Memory Buffer Base Address (BMBBA): ffffffffffffffff
cmbmsc : ffffffffffffffff
Controller Base Address (CBA) : fffffffffffff
Controller Memory Space Enable (CMSE): 1
Capabilities Registers Enabled (CRE) : CMBLOC and CMBSZ registers are enabled
cmbsts : ffffffff
Controller Base Address Invalid (CBAI): 1
pmrcap : ffffffff
Controller Memory Space Supported (CMSS) : Referencing PMR with host supplied addresses is Supported
Persistent Memory Region Timeout (PMRTO): ff
Persistent Memory Region Write Barrier Mechanisms(PMRWBM): f
Persistent Memory Region Time Units (PMRTU): PMR time unit is minutes
Base Indicator Register (BIR): 7
Write Data Support (WDS): Write data to the PMR is supported
Read Data Support (RDS): Read data from the PMR is supported
pmrctl : ffffffff
Enable (EN): PMR is READY
pmrsts : ffffffff
Controller Base Address Invalid (CBAI): 1
Health Status (HSTS): Reserved
Not Ready (NRDY): The Persistent Memory Region is Not Ready to process PCI Express memory read and write requests
pmrebs : ffffffff
PMR Elasticity Buffer Size Base (PMRWBZ): ffffff
Read Bypass Behavior : memory reads not conflicting with memory writes in the PMR Elasticity Buffer SHALL bypass those memory writes
PMR Elasticity Buffer Size Units (PMRSZU): Reserved
pmrswtp : ffffffff
PMR Sustained Write Throughput (PMRSWTV): ffffff
PMR Sustained Write Throughput Units (PMRSWTU): Reserved/second
pmrmsc : ffffffffffffffff
Controller Base Address (CBA) : fffffffffffff
Controller Memory Space Enable (CMSE : 0
'Storage System' 카테고리의 다른 글
| [정보스토리지와관리] 시작전.. (0) | 2020.03.15 |
|---|---|
| [NVMe] Spec 1.4 정리 - 4장 Data Structures (0) | 2020.02.20 |
| [NVMe] Spec 1.4 정리 - 2장 System BUS (PCI Express) Registers (3/?) (0) | 2020.01.16 |
| [NVMe] Spec 1.4 정리 - 2장 System BUS (PCI Express) Registers (2/?) (0) | 2020.01.14 |
| [NVMe] Spec 1.4 정리 - 2장 System BUS (PCI Express) Registers (1/?) (0) | 2020.01.08 |