target/riscv: do not mask unsupported QEMU extensions in write_misa()

The masking done using env->misa_ext_mask already filters any extension
that QEMU doesn't support. If the hart supports the extension then QEMU
supports it as well.

If the masking done by env->misa_ext_mask is somehow letting unsupported
QEMU extensions pass by, misa_ext_mask itself needs to be fixed instead.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-ID: <20230222185205.355361-3-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 1b0a0c1..e149b45 100644 (file)
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1356,9 +1356,6 @@ static RISCVException write_misa(CPURISCVState *env, int csrno,
     /* Mask extensions that are not supported by this hart */
     val &= env->misa_ext_mask;
 
-    /* Mask extensions that are not supported by QEMU */
-    val &= (RVI | RVE | RVM | RVA | RVF | RVD | RVC | RVS | RVU | RVV);
-
     /* 'D' depends on 'F', so clear 'D' if 'F' is not present */
     if ((val & RVD) && !(val & RVF)) {
         val &= ~RVD;