Re: [Qemu-arm] [Qemu-devel] [RFC PATCH v2 22/23] target/arm: Restrict semi-hosting to TCG

[Alex Bennée]

Philippe Mathieu-Daudé <address@hidden> writes:

> Per Peter Maydell:
>
>   semihosting hooks either SVC or HLT instructions, and inside KVM
>   both of those go to EL1, ie to the guest, and can't be trapped to
>   KVM.
>
> Let check_for_semihosting() return False when not running on TCG.
>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>

Reviewed-by: Alex Bennée <address@hidden>

> ---
>  target/arm/helper.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 8b7ce0561b..a3843a5508 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -20,7 +20,6 @@
>  #include "qemu/crc32c.h"
>  #include "qemu/qemu-print.h"
>  #include "exec/exec-all.h"
> -#include "arm_ldst.h"
>  #include <zlib.h> /* For crc32 */
>  #include "hw/semihosting/semihost.h"
>  #include "sysemu/cpus.h"
> @@ -30,6 +29,9 @@
>  #include "qapi/qapi-commands-target.h"
>  #include "qapi/error.h"
>  #include "qemu/guest-random.h"
> +#ifdef CONFIG_TCG
> +#include "arm_ldst.h"
> +#endif
>
>  #define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */
>
> @@ -8270,6 +8272,7 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs)
>
>  static inline bool check_for_semihosting(CPUState *cs)
>  {
> +#ifdef CONFIG_TCG
>      /* Check whether this exception is a semihosting call; if so
>       * then handle it and return true; otherwise return false.
>       */
> @@ -8345,6 +8348,9 @@ static inline bool check_for_semihosting(CPUState *cs)
>          env->regs[0] = do_arm_semihosting(env);
>          return true;
>      }
> +#else
> +    return false;
> +#endif
>  }
>
>  /* Handle a CPU exception for A and R profile CPUs.


--
Alex Bennée