target/riscv: Add support for mconfigptr

RISC-V privileged specification v1.12 introduced a mconfigptr
which will hold the physical address of a configuration data
structure. As Qemu doesn't have a configuration data structure,
is read as zero which is valid as per the priv spec.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220303185440.512391-5-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 0fe01d7..48d92a8 100644 (file)
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -148,6 +148,7 @@
 #define CSR_MARCHID         0xf12
 #define CSR_MIMPID          0xf13
 #define CSR_MHARTID         0xf14
+#define CSR_MCONFIGPTR      0xf15
 
 /* Machine Trap Setup */
 #define CSR_MSTATUS         0x300

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 1400027..6590cc8 100644 (file)
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -3110,6 +3110,8 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_MIMPID]    = { "mimpid",    any,   read_zero    },
     [CSR_MHARTID]   = { "mhartid",   any,   read_mhartid },
 
+    [CSR_MCONFIGPTR]  = { "mconfigptr", any,   read_zero,
+                                        .min_priv_ver = PRIV_VERSION_1_12_0 },
     /* Machine Trap Setup */
     [CSR_MSTATUS]     = { "mstatus",    any,   read_mstatus,     write_mstatus, NULL,
                                                read_mstatus_i128                   },