target/riscv: add rva22u64 profile definition

The rva22U64 profile, described in:

https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc#rva22-profiles

Contains a set of CPU extensions aimed for 64-bit userspace
applications. Enabling this set to be enabled via a single user flag
makes it convenient to enable a predictable set of features for the CPU,
giving users more predicability when running/testing their workloads.

QEMU implements all possible extensions of this profile. All the so
called 'synthetic extensions' described in the profile that are cache
related are ignored/assumed enabled (Za64rs, Zic64b, Ziccif, Ziccrse,
Ziccamoa, Zicclsm) since we do not implement a cache model.

An abstraction called RISCVCPUProfile is created to store the profile.
'ext_offsets' contains mandatory extensions that QEMU supports. Same
thing with the 'misa_ext' mask. Optional extensions must be enabled
manually in the command line if desired.

The design here is to use the common target/riscv/cpu.c file to store
the profile declaration and export it to the accelerator files. Each
accelerator is then responsible to expose it (or not) to users and how
to enable the extensions.

Next patches will implement the profile for TCG and KVM.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20231218125334.37184-9-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

2 files changed, 44 insertions, 0 deletions

diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 29fdd64298..199b581380 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -1523,6 +1523,38 @@ Property riscv_cpu_options[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
+/*
+ * RVA22U64 defines some 'named features' or 'synthetic extensions'
+ * that are cache related: Za64rs, Zic64b, Ziccif, Ziccrse, Ziccamoa
+ * and Zicclsm. We do not implement caching in QEMU so we'll consider
+ * all these named features as always enabled.
+ *
+ * There's no riscv,isa update for them (nor for zic64b, despite it
+ * having a cfg offset) at this moment.
+ */
+static RISCVCPUProfile RVA22U64 = {
+    .name = "rva22u64",
+    .misa_ext = RVI | RVM | RVA | RVF | RVD | RVC | RVU,
+    .ext_offsets = {
+        CPU_CFG_OFFSET(ext_zicsr), CPU_CFG_OFFSET(ext_zihintpause),
+        CPU_CFG_OFFSET(ext_zba), CPU_CFG_OFFSET(ext_zbb),
+        CPU_CFG_OFFSET(ext_zbs), CPU_CFG_OFFSET(ext_zfhmin),
+        CPU_CFG_OFFSET(ext_zkt), CPU_CFG_OFFSET(ext_zicntr),
+        CPU_CFG_OFFSET(ext_zihpm), CPU_CFG_OFFSET(ext_zicbom),
+        CPU_CFG_OFFSET(ext_zicbop), CPU_CFG_OFFSET(ext_zicboz),
+
+        /* mandatory named features for this profile */
+        CPU_CFG_OFFSET(zic64b),
+
+        RISCV_PROFILE_EXT_LIST_END
+    }
+};
+
+RISCVCPUProfile *riscv_profiles[] = {
+    &RVA22U64,
+    NULL,
+};
+
 static Property riscv_cpu_properties[] = {
     DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true),
 
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index bfa42a0393..5af1666dc0 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -76,6 +76,18 @@ const char *riscv_get_misa_ext_description(uint32_t bit);
 
 #define CPU_CFG_OFFSET(_prop) offsetof(struct RISCVCPUConfig, _prop)
 
+typedef struct riscv_cpu_profile {
+    const char *name;
+    uint32_t misa_ext;
+    bool enabled;
+    bool user_set;
+    const int32_t ext_offsets[];
+} RISCVCPUProfile;
+
+#define RISCV_PROFILE_EXT_LIST_END -1
+
+extern RISCVCPUProfile *riscv_profiles[];
+
 /* Privileged specification version */
 enum {
     PRIV_VERSION_1_10_0 = 0,