[PATCH 1/1] target/riscv: Fix vsip vsie CSR ops in M and HS mode

[LIU Zhiwei]

When V=1, instructions that normally read or modify a supervisor CSR
shall instead access the corresponding VS CSR. And the VS CSRs can be
accessed as themselves from M-mode or HS-mode.

In M and HS mode, VSIP or VSIE should be written normally instead of
shift by 1.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
---
 target/riscv/csr.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index fe5628fea6..0cce474d3d 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -837,16 +837,16 @@ static RISCVException read_sie(CPURISCVState *env, int 
csrno,
 static RISCVException write_vsie(CPURISCVState *env, int csrno,
                                  target_ulong val)
 {
-    /* Shift the S bits to their VS bit location in mie */
     target_ulong newval = (env->mie & ~VS_MODE_INTERRUPTS) |
-                          ((val << 1) & env->hideleg & VS_MODE_INTERRUPTS);
+                          (val & env->hideleg & VS_MODE_INTERRUPTS);
     return write_mie(env, CSR_MIE, newval);
 }
 
 static int write_sie(CPURISCVState *env, int csrno, target_ulong val)
 {
     if (riscv_cpu_virt_enabled(env)) {
-        write_vsie(env, CSR_VSIE, val);
+        /* Shift the S bits to their VS bit location in mie */
+        write_vsie(env, CSR_VSIE, val << 1);
     } else {
         target_ulong newval = (env->mie & ~S_MODE_INTERRUPTS) |
                               (val & S_MODE_INTERRUPTS);
@@ -950,12 +950,9 @@ static RISCVException rmw_vsip(CPURISCVState *env, int 
csrno,
                                target_ulong *ret_value,
                                target_ulong new_value, target_ulong write_mask)
 {
-    /* Shift the S bits to their VS bit location in mip */
-    int ret = rmw_mip(env, 0, ret_value, new_value << 1,
-                      (write_mask << 1) & vsip_writable_mask & env->hideleg);
+    int ret = rmw_mip(env, 0, ret_value, new_value,
+                      write_mask & vsip_writable_mask & env->hideleg);
     *ret_value &= VS_MODE_INTERRUPTS;
-    /* Shift the VS bits to their S bit location in vsip */
-    *ret_value >>= 1;
     return ret;
 }
 
@@ -966,7 +963,11 @@ static RISCVException rmw_sip(CPURISCVState *env, int 
csrno,
     int ret;
 
     if (riscv_cpu_virt_enabled(env)) {
-        ret = rmw_vsip(env, CSR_VSIP, ret_value, new_value, write_mask);
+        /* Shift the S bits to their VS bit location in mip */
+        ret = rmw_vsip(env, CSR_VSIP, ret_value, new_value << 1,
+                       write_mask << 1);
+        /* Shift the VS bits to their S bit location in vsip */
+        *ret_value >>= 1;
     } else {
         ret = rmw_mip(env, CSR_MSTATUS, ret_value, new_value,
                       write_mask & env->mideleg & sip_writable_mask);
-- 
2.25.1