[PATCH] target/arm: HVC at EL3 should go to EL3, not EL2

[PATCH] target/arm: HVC at EL3 should go to EL3, not EL2

[Peter Maydell]

AArch64 permits code at EL3 to use the HVC instruction; however the
exception we take should go to EL3, not down to EL2 (see the pseudocode
AArch64.CallHypervisor()). Fix the target EL.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/tcg/translate-a64.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index 41484d8ae54..a2e49c39f9f 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -2351,6 +2351,8 @@ static bool trans_SVC(DisasContext *s, arg_i *a)
 
 static bool trans_HVC(DisasContext *s, arg_i *a)
 {
+    int target_el = s->current_el == 3 ? 3 : 2;
+
     if (s->current_el == 0) {
         unallocated_encoding(s);
         return true;
@@ -2363,7 +2365,7 @@ static bool trans_HVC(DisasContext *s, arg_i *a)
     gen_helper_pre_hvc(tcg_env);
     /* Architecture requires ss advance before we do the actual work */
     gen_ss_advance(s);
-    gen_exception_insn_el(s, 4, EXCP_HVC, syn_aa64_hvc(a->imm), 2);
+    gen_exception_insn_el(s, 4, EXCP_HVC, syn_aa64_hvc(a->imm), target_el);
     return true;
 }
 
-- 
2.34.1

Re: [PATCH] target/arm: HVC at EL3 should go to EL3, not EL2

[Edgar E. Iglesias]

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On Thu, Nov 9, 2023 at 4:20 PM Peter Maydell <peter.maydell@linaro.org>
wrote:

> AArch64 permits code at EL3 to use the HVC instruction; however the
> exception we take should go to EL3, not down to EL2 (see the pseudocode
> AArch64.CallHypervisor()). Fix the target EL.
>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>

Reviewed-by: Edgar E. Iglesias <edgar@zeroasic.com>



> ---
>  target/arm/tcg/translate-a64.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/target/arm/tcg/translate-a64.c
> b/target/arm/tcg/translate-a64.c
> index 41484d8ae54..a2e49c39f9f 100644
> --- a/target/arm/tcg/translate-a64.c
> +++ b/target/arm/tcg/translate-a64.c
> @@ -2351,6 +2351,8 @@ static bool trans_SVC(DisasContext *s, arg_i *a)
>
>  static bool trans_HVC(DisasContext *s, arg_i *a)
>  {
> +    int target_el = s->current_el == 3 ? 3 : 2;
> +
>      if (s->current_el == 0) {
>          unallocated_encoding(s);
>          return true;
> @@ -2363,7 +2365,7 @@ static bool trans_HVC(DisasContext *s, arg_i *a)
>      gen_helper_pre_hvc(tcg_env);
>      /* Architecture requires ss advance before we do the actual work */
>      gen_ss_advance(s);
> -    gen_exception_insn_el(s, 4, EXCP_HVC, syn_aa64_hvc(a->imm), 2);
> +    gen_exception_insn_el(s, 4, EXCP_HVC, syn_aa64_hvc(a->imm),
> target_el);
>      return true;
>  }
>
> --
> 2.34.1
>
>
>

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Re: [PATCH] target/arm: HVC at EL3 should go to EL3, not EL2

[Richard Henderson]

On 11/9/23 07:19, Peter Maydell wrote:
> AArch64 permits code at EL3 to use the HVC instruction; however the
> exception we take should go to EL3, not down to EL2 (see the pseudocode
> AArch64.CallHypervisor()). Fix the target EL.
> 
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   target/arm/tcg/translate-a64.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)

r~