Commit 85d38315fd for qemu.org

commit 85d38315fd19cda7fcfec5350f27cdfa15742600
Author: Christian S. Lima <christianslima@proton.me>
Date:   Sat Aug 8 03:18:54 2026 +0000

    target/riscv/tcg: sret in virtual user mode raises virtual instruction exception

    Currently, when a `sret` is executed in virtual user mode, qemu
    raise an `illegal instruction exception`, but in this case the correct
    behavior is to raise a `virtual instruction exception` and the code
    already contains a check to it, but it's not enough to catch. This
    patch is useful to improve the correctness of the virtualization of
    the risc v architecture.

    Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3622

    Signed-off-by: Christian S. Lima <christianslima@proton.me>
    Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
    Message-ID: <20260808031849.59726-1-christianslima@proton.me>
    Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/tcg/op_helper.c b/target/riscv/tcg/op_helper.c
index a7bd42d2c6..3e94005d2b 100644
--- a/target/riscv/tcg/op_helper.c
+++ b/target/riscv/tcg/op_helper.c
@@ -308,6 +308,11 @@ target_ulong helper_sret(CPURISCVState *env)
     const privilege_mode_t src_priv = env->priv;
     const bool src_virt = env->virt_enabled;

+    if ((env->virt_enabled && env->priv < PRV_S) ||
+        (env->virt_enabled && get_field(env->hstatus, HSTATUS_VTSR))) {
+        riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
+    }
+
     if (!(env->priv >= PRV_S)) {
         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
     }
@@ -323,10 +328,6 @@ target_ulong helper_sret(CPURISCVState *env)
         riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
     }

-    if (env->virt_enabled && get_field(env->hstatus, HSTATUS_VTSR)) {
-        riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
-    }
-
     mstatus = env->mstatus;
     prev_priv = get_field(mstatus, MSTATUS_SPP);
     mstatus = set_field(mstatus, MSTATUS_SIE,