Add ssqosid extension and csr yaml

arch/csr/Ssqosid/srmcfg.yaml

@@ -0,0 +1,44 @@
+# yaml-language-server: $schema=../../../schemas/csr_schema.json
+$schema: csr_schema.json#
+kind: csr
+name: srmcfg
+long_name: Supervisor Resource Management Configuration
+address: 0x5C0 #Until the extension is finalized and assigned an official address by the RISC-V Foundation, srmcfg will use a placeholder/custom address
+priv_mode: S
+length: SXLEN
+definedBy: Ssqosid
+description: |
+  The srmcfg register is an SXLEN-bit read/write register used to configure a Resource Control ID (RCID) and a Monitoring Counter ID (MCID).
+  Both RCID and MCID are WARL fields.
+
+  The RCID and MCID accompany each request made by the hart to shared resource controllers.
+  The RCID is used to determine the resource allocations (e.g., cache occupancy limits, memory bandwidth limits, etc.) to enforce.
+  The MCID is used to identify a counter to monitor resource usage.
+
+  The RCID and MCID configured in the srmcfg CSR apply to all privilege modes of software execution on that hart by default,
+  but this behavior may be overridden by future extensions.
+
+  If extension Smstateen is implemented together with Ssqosid, then Ssqosid also requires the SRMCFG bit in mstateen0 to be implemented.
+  If mstateen0.SRMCFG is 0, attempts to access srmcfg in privilege modes less privileged than M-mode raise an illegal-instruction exception.
+  If mstateen0.SRMCFG is 1 or if extension Smstateen is not implemented, attempts to access srmcfg when V=1 raise a virtual-instruction exception.
+
+  A reset value of 0 is suggested for the RCID field matching resource controllers' default behavior of associating all capacity with RCID=0.
+  The MCID reset value does not affect functionality and may be implementation-defined.
+
+fields:
+  RCID:
+    location_rv32: 15-0
+    location_rv64: 15-0
+    type: RW
+    description: |
+      The RCID is used to determine the resource allocations (e.g., cache occupancy limits,
+       memory bandwidth limits, etc.) to enforce.
+    reset_value: 0
+
+  MCID:
+    location_rv32: 31-16
+    location_rv64: 31-16
+    type: RW
+    description: |
+      The MCID is used to identify a counter to monitor resource usage.
+    reset_value: 0

arch/ext/Ssqosid.yaml

@@ -0,0 +1,40 @@
+# yaml-language-server: $schema=../../schemas/ext_schema.json
+
+$schema: "ext_schema.json#"
+kind: extension
+name: Ssqosid
+type: privileged
+long_name: Quality-of-Service Identifiers
+description: |
+  Quality of Service (QoS) is defined as the minimal end-to-end performance guaranteed in advance by a service level agreement (SLA) to a workload.
+  Performance metrics might include measures such as instructions per cycle (IPC), latency of service, etc.
+
+  When multiple workloads execute concurrently on modern processors—equipped with large core counts, multiple cache hierarchies, and multiple memory
+  controllers—the performance of any given workload becomes less deterministic, or even non-deterministic, due to shared resource contention.
+
+  To manage performance variability, system software needs resource allocation and monitoring capabilities.
+  These capabilities allow for the reservation of resources like cache and bandwidth, thus meeting individual performance targets while minimizing interference.
+  For resource management, hardware should provide monitoring features that allow system software to profile workload resource consumption and allocate resources accordingly.
+
+  To facilitate this, the QoS Identifiers extension (Ssqosid) introduces the srmcfg register,
+  which configures a hart with two identifiers: a Resource Control ID (RCID) and a Monitoring Counter ID (MCID).
+  These identifiers accompany each request issued by the hart to shared resource controllers.
+
+  Additional metadata, like the nature of the memory access and the ID of the originating supervisor domain,
+  can accompany RCID and MCID. Resource controllers may use this metadata for differentiated service such as a different capacity allocation for code storage vs.data storage.
+  Resource controllers can use this data for security policies such as not exposing statistics of one security domain to another.
+
+  These identifiers are crucial for the RISC-V Capacity and Bandwidth Controller QoS Register Interface (CBQRI) specification,
+  which provides methods for setting resource usage limits and monitoring resource consumption.
+  The RCID controls resource allocations, while the MCID is used for tracking resource usage.
+
+  The Ssqosid extension does not require that S-mode mode be implemented.
+versions:
+  - version: "1.0.0"
+    state: ratified
+    ratification_date: "2024-11"
+    url: "https://github.com/riscv/riscv-isa-manual/releases/tag/riscv-isa-release-5308687-2025-04-22"
+    requires:
+      allOf:
+        - name: S
+          version: ~> 1.13