target/riscv: Introduce privilege version field in the CSR ops.

To allow/disallow the CSR access based on the privilege spec, a new field
in the csr_ops is introduced. It also adds the privileged specification
version (v1.12) for the CSRs introduced in the v1.12. This includes the
new ratified extensions such as Vector, Hypervisor and secconfig CSR.
However, it doesn't enforce the privilege version in this commit.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220303185440.512391-4-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

2 files changed, 70 insertions, 35 deletions

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 19c3b66..5139110 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -658,6 +658,8 @@ typedef struct {
     riscv_csr_op_fn op;
     riscv_csr_read128_fn read128;
     riscv_csr_write128_fn write128;
+    /* The default priv spec version should be PRIV_VERSION_1_10_0 (i.e 0) */
+    uint32_t min_priv_ver;
 } riscv_csr_operations;
 
 /* CSR function table constants */
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 341c2e6..1400027 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -3070,13 +3070,20 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_FRM]      = { "frm",      fs,     read_frm,     write_frm    },
     [CSR_FCSR]     = { "fcsr",     fs,     read_fcsr,    write_fcsr   },
     /* Vector CSRs */
-    [CSR_VSTART]   = { "vstart",   vs,     read_vstart,  write_vstart },
-    [CSR_VXSAT]    = { "vxsat",    vs,     read_vxsat,   write_vxsat  },
-    [CSR_VXRM]     = { "vxrm",     vs,     read_vxrm,    write_vxrm   },
-    [CSR_VCSR]     = { "vcsr",     vs,     read_vcsr,    write_vcsr   },
-    [CSR_VL]       = { "vl",       vs,     read_vl                    },
-    [CSR_VTYPE]    = { "vtype",    vs,     read_vtype                 },
-    [CSR_VLENB]    = { "vlenb",    vs,     read_vlenb                 },
+    [CSR_VSTART]   = { "vstart",   vs,    read_vstart,  write_vstart,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VXSAT]    = { "vxsat",    vs,    read_vxsat,   write_vxsat,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VXRM]     = { "vxrm",     vs,    read_vxrm,    write_vxrm,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VCSR]     = { "vcsr",     vs,    read_vcsr,    write_vcsr,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VL]       = { "vl",       vs,    read_vl,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VTYPE]    = { "vtype",    vs,    read_vtype,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VLENB]    = { "vlenb",    vs,    read_vlenb,
+                                          .min_priv_ver = PRIV_VERSION_1_12_0 },
     /* User Timers and Counters */
     [CSR_CYCLE]    = { "cycle",    ctr,    read_instret  },
     [CSR_INSTRET]  = { "instret",  ctr,    read_instret  },
@@ -3185,33 +3192,58 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_SIEH]       = { "sieh",   aia_smode32, NULL, NULL, rmw_sieh },
     [CSR_SIPH]       = { "siph",   aia_smode32, NULL, NULL, rmw_siph },
 
-    [CSR_HSTATUS]     = { "hstatus",     hmode,   read_hstatus,     write_hstatus     },
-    [CSR_HEDELEG]     = { "hedeleg",     hmode,   read_hedeleg,     write_hedeleg     },
-    [CSR_HIDELEG]     = { "hideleg",     hmode,   NULL,   NULL,     rmw_hideleg       },
-    [CSR_HVIP]        = { "hvip",        hmode,   NULL,   NULL,     rmw_hvip          },
-    [CSR_HIP]         = { "hip",         hmode,   NULL,   NULL,     rmw_hip           },
-    [CSR_HIE]         = { "hie",         hmode,   NULL,   NULL,     rmw_hie           },
-    [CSR_HCOUNTEREN]  = { "hcounteren",  hmode,   read_hcounteren,  write_hcounteren  },
-    [CSR_HGEIE]       = { "hgeie",       hmode,   read_hgeie,       write_hgeie       },
-    [CSR_HTVAL]       = { "htval",       hmode,   read_htval,       write_htval       },
-    [CSR_HTINST]      = { "htinst",      hmode,   read_htinst,      write_htinst      },
-    [CSR_HGEIP]       = { "hgeip",       hmode,   read_hgeip,       NULL              },
-    [CSR_HGATP]       = { "hgatp",       hmode,   read_hgatp,       write_hgatp       },
-    [CSR_HTIMEDELTA]  = { "htimedelta",  hmode,   read_htimedelta,  write_htimedelta  },
-    [CSR_HTIMEDELTAH] = { "htimedeltah", hmode32, read_htimedeltah, write_htimedeltah },
-
-    [CSR_VSSTATUS]    = { "vsstatus",    hmode,   read_vsstatus,    write_vsstatus    },
-    [CSR_VSIP]        = { "vsip",        hmode,   NULL,    NULL,    rmw_vsip          },
-    [CSR_VSIE]        = { "vsie",        hmode,   NULL,    NULL,    rmw_vsie          },
-    [CSR_VSTVEC]      = { "vstvec",      hmode,   read_vstvec,      write_vstvec      },
-    [CSR_VSSCRATCH]   = { "vsscratch",   hmode,   read_vsscratch,   write_vsscratch   },
-    [CSR_VSEPC]       = { "vsepc",       hmode,   read_vsepc,       write_vsepc       },
-    [CSR_VSCAUSE]     = { "vscause",     hmode,   read_vscause,     write_vscause     },
-    [CSR_VSTVAL]      = { "vstval",      hmode,   read_vstval,      write_vstval      },
-    [CSR_VSATP]       = { "vsatp",       hmode,   read_vsatp,       write_vsatp       },
-
-    [CSR_MTVAL2]      = { "mtval2",      hmode,   read_mtval2,      write_mtval2      },
-    [CSR_MTINST]      = { "mtinst",      hmode,   read_mtinst,      write_mtinst      },
+    [CSR_HSTATUS]     = { "hstatus",     hmode,   read_hstatus,   write_hstatus,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HEDELEG]     = { "hedeleg",     hmode,   read_hedeleg,   write_hedeleg,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HIDELEG]     = { "hideleg",     hmode,   NULL,   NULL, rmw_hideleg,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HVIP]        = { "hvip",        hmode,   NULL,   NULL,   rmw_hvip,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HIP]         = { "hip",         hmode,   NULL,   NULL,   rmw_hip,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HIE]         = { "hie",         hmode,   NULL,   NULL,    rmw_hie,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HCOUNTEREN]  = { "hcounteren",  hmode,   read_hcounteren, write_hcounteren,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HGEIE]       = { "hgeie",       hmode,   read_hgeie,       write_hgeie,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HTVAL]       = { "htval",       hmode,   read_htval,     write_htval,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HTINST]      = { "htinst",      hmode,   read_htinst,    write_htinst,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HGEIP]       = { "hgeip",       hmode,   read_hgeip,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HGATP]       = { "hgatp",       hmode,   read_hgatp,     write_hgatp,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HTIMEDELTA]  = { "htimedelta",  hmode,   read_htimedelta, write_htimedelta,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_HTIMEDELTAH] = { "htimedeltah", hmode32, read_htimedeltah, write_htimedeltah,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+
+    [CSR_VSSTATUS]    = { "vsstatus",    hmode,   read_vsstatus,  write_vsstatus,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSIP]        = { "vsip",        hmode,   NULL,    NULL,  rmw_vsip,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSIE]        = { "vsie",        hmode,   NULL,    NULL,    rmw_vsie ,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSTVEC]      = { "vstvec",      hmode,   read_vstvec,    write_vstvec,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSSCRATCH]   = { "vsscratch",   hmode,   read_vsscratch, write_vsscratch,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSEPC]       = { "vsepc",       hmode,   read_vsepc,     write_vsepc,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSCAUSE]     = { "vscause",     hmode,   read_vscause,   write_vscause,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSTVAL]      = { "vstval",      hmode,   read_vstval,    write_vstval,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_VSATP]       = { "vsatp",       hmode,   read_vsatp,     write_vsatp,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+
+    [CSR_MTVAL2]      = { "mtval2",      hmode,   read_mtval2,    write_mtval2,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
+    [CSR_MTINST]      = { "mtinst",      hmode,   read_mtinst,    write_mtinst,
+                                         .min_priv_ver = PRIV_VERSION_1_12_0 },
 
     /* Virtual Interrupts and Interrupt Priorities (H-extension with AIA) */
     [CSR_HVIEN]       = { "hvien",       aia_hmode, read_zero, write_ignore },
@@ -3245,7 +3277,8 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_VSIPH]       = { "vsiph",       aia_hmode32, NULL, NULL, rmw_vsiph },
 
     /* Physical Memory Protection */
-    [CSR_MSECCFG]    = { "mseccfg",  epmp, read_mseccfg, write_mseccfg },
+    [CSR_MSECCFG]    = { "mseccfg",  epmp, read_mseccfg, write_mseccfg,
+                                     .min_priv_ver = PRIV_VERSION_1_12_0 },
     [CSR_PMPCFG0]    = { "pmpcfg0",   pmp, read_pmpcfg,  write_pmpcfg  },
     [CSR_PMPCFG1]    = { "pmpcfg1",   pmp, read_pmpcfg,  write_pmpcfg  },
     [CSR_PMPCFG2]    = { "pmpcfg2",   pmp, read_pmpcfg,  write_pmpcfg  },