On Mon, 09 Dec 2019 10:11:04 PST (-0800), Alistair Francis wrote:
Update the CSR permission checking to work correctly when we are in
HS-mode.

Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
---
 target/riscv/csr.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 6a0a59edfd..eebfc1823d 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -802,12 +802,22 @@ int riscv_csrrw(CPURISCVState *env, int csrno, 
target_ulong *ret_value,

     /* check privileges and return -1 if check fails */
 #if !defined(CONFIG_USER_ONLY)
-    int csr_priv = get_field(csrno, 0x300);
+    int effective_priv = env->priv;
     int read_only = get_field(csrno, 0xC00) == 3;
-    if ((!env->debugger) && (env->priv < csr_priv)) {
-        return -1;
+
+    if (riscv_has_ext(env, RVH) &&
+        env->priv == PRV_S &&
+        !riscv_cpu_virt_enabled(env)) {
+        /*
+         * We are in S mode without virtualisation, therefore we are in HS 
Mode.
+         * Add 1 to the effective privledge level to allow us to access the
+         * Hypervisor CSRs.
+         */
+        effective_priv++;
     }
-    if (write_mask && read_only) {
+
+    if ((write_mask && read_only) ||
+        (!env->debugger && (effective_priv < get_field(csrno, 0x300)))) {
         return -1;
     }
 #endif

Reviewed-by: Palmer Dabbelt <palmerdabb...@google.com>

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