target/arm: Honour -semihosting-config userspace=on

Honour the commandline -semihosting-config userspace=on option,
instead of never permitting userspace semihosting calls in system
emulation mode, by passing the correct value to the is_userspace
argument of semihosting_enabled(), instead of manually checking and
always forbidding semihosting if the guest is in userspace and this
isn't the linux-user build.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-3-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 1 insertions, 11 deletions

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 3decc8d..9bed336 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -2219,17 +2219,7 @@ static void disas_exc(DisasContext *s, uint32_t insn)
          * it is required for halting debug disabled: it will UNDEF.
          * Secondly, "HLT 0xf000" is the A64 semihosting syscall instruction.
          */
-        if (semihosting_enabled(false) && imm16 == 0xf000) {
-#ifndef CONFIG_USER_ONLY
-            /* In system mode, don't allow userspace access to semihosting,
-             * to provide some semblance of security (and for consistency
-             * with our 32-bit semihosting).
-             */
-            if (s->current_el == 0) {
-                unallocated_encoding(s);
-                break;
-            }
-#endif
+        if (semihosting_enabled(s->current_el == 0) && imm16 == 0xf000) {
             gen_exception_internal_insn(s, s->pc_curr, EXCP_SEMIHOST);
         } else {
             unallocated_encoding(s);