Re: [PATCH 10/18] target/riscv: gdbstub: Turn on debugger mode before calling CSR predicate()

[LIU Zhiwei]

On 2023/2/14 2:02, Bin Meng wrote:

Since commit 94452ac4cf26 ("target/riscv: remove fflags, frm, and fcsr from 
riscv-*-fpu.xml")
the 3 FPU CSRs are removed from the XML target decription. The
original intent of that commit was based on the assumption that
the 3 FPU CSRs will show up in the riscv-csr.xml so the ones in
riscv-*-fpu.xml are redundant. But unforuantely that is not ture.
As the FPU CSR predicate() has a run-time check on MSTATUS.FS,
at the time when CSR XML is generated MSTATUS.FS is unset, hence
no FPU CSRs will be reported.

The FPU CSR predicate() already considered such a case of being
accessed by a debugger. All we need to do is to turn on debugger
mode before calling predicate().

Signed-off-by: Bin Meng <bm...@tinylab.org>
---

  target/riscv/gdbstub.c | 9 +++++++++
  1 file changed, 9 insertions(+)

diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index 294f0ceb1c..ef52f41460 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -280,6 +280,10 @@ static int riscv_gen_dynamic_csr_xml(CPUState *cs, int 
base_reg)
      int bitsize = 16 << env->misa_mxl_max;
      int i;

+#if !defined(CONFIG_USER_ONLY)

+    env->debugger = true;
+#endif
+
      /* Until gdb knows about 128-bit registers */
      if (bitsize > 64) {
          bitsize = 64;
@@ -308,6 +312,11 @@ static int riscv_gen_dynamic_csr_xml(CPUState *cs, int 
base_reg)
      g_string_append_printf(s, "</feature>");

cpu->dyn_csr_xml = g_string_free(s, false);

+
+#if !defined(CONFIG_USER_ONLY)
+    env->debugger = false;
+#endif
+

Reviewed-by: LIU Zhiwei <zhiwei_...@linux.alibaba.com>

Zhiwei

      return CSR_TABLE_SIZE;
  }