From: Jim Shu <[email protected]>

In VU/VS mode, accessing $ssp CSR will trigger the virtual instruction
exception instead of illegal instruction exception if SSE is disabled
via xenvcfg CSRs.

This is from RISC-V CFI v1.0 spec ch2.2.4. Shadow Stack Pointer

Signed-off-by: Jim Shu <[email protected]>
Reviewed-by: Alistair Francis <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Alistair Francis <[email protected]>
(cherry picked from commit 84c1605b7606d810ded4c1c3a2717f158dc89e3f)
Signed-off-by: Michael Tokarev <[email protected]>

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 76e2f7e1d5..76e77ae2d1 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -202,6 +202,8 @@ static RISCVException cfi_ss(CPURISCVState *env, int csrno)
 #if !defined(CONFIG_USER_ONLY)
         if (env->debugger) {
             return RISCV_EXCP_NONE;
+        } else if (env->virt_enabled) {
+            return RISCV_EXCP_VIRT_INSTRUCTION_FAULT;
         }
 #endif
         return RISCV_EXCP_ILLEGAL_INST;
-- 
2.47.3


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