[Qemu-devel] [PATCH v2] target-arm: Use the right MMU index in arm_regime_using_lpae_format

[Qemu-devel] [PATCH v2] target-arm: Use the right MMU index in arm_regime_using_lpae_format

[Alvise Rigo]

arm_regime_using_lpae_format checks whether the LPAE extension is used
for stage 1 translation regimes. MMU indexes not exclusively of a stage 1
regime won't work with this method.

In case of ARMMMUIdx_S12NSE0 or ARMMMUIdx_S12NSE1, offset these values
by ARMMMUIdx_S1NSE0 to get the right index indicating a stage 1
translation regime.

Rename also the function to arm_s1_regime_using_lpae_format and update
the comments to reflect the change.

Signed-off-by: Alvise Rigo <a.rigo@virtualopensystems.com>
---
 target-arm/helper.c    | 12 ++++++++----
 target-arm/internals.h |  5 +++--
 target-arm/op_helper.c |  2 +-
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 59d5a41..faeaaa8 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5996,11 +5996,15 @@ static inline bool regime_using_lpae_format(CPUARMState *env,
     return false;
 }
 
-/* Returns true if the translation regime is using LPAE format page tables.
- * Used when raising alignment exceptions, whose FSR changes depending on
- * whether the long or short descriptor format is in use. */
-bool arm_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx)
+/* Returns true if the stage 1 translation regime is using LPAE format page
+ * tables. Used when raising alignment exceptions, whose FSR changes depending
+ * on whether the long or short descriptor format is in use. */
+bool arm_s1_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx)
 {
+    if (mmu_idx == ARMMMUIdx_S12NSE0 || mmu_idx == ARMMMUIdx_S12NSE1) {
+        mmu_idx += ARMMMUIdx_S1NSE0;
+    }
+
     return regime_using_lpae_format(env, mmu_idx);
 }
 
diff --git a/target-arm/internals.h b/target-arm/internals.h
index b925aaa..d226bbe 100644
--- a/target-arm/internals.h
+++ b/target-arm/internals.h
@@ -441,8 +441,9 @@ struct ARMMMUFaultInfo {
 bool arm_tlb_fill(CPUState *cpu, vaddr address, int rw, int mmu_idx,
                   uint32_t *fsr, ARMMMUFaultInfo *fi);
 
-/* Return true if the translation regime is using LPAE format page tables */
-bool arm_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx);
+/* Return true if the stage 1 translation regime is using LPAE format page
+ * tables */
+bool arm_s1_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx);
 
 /* Raise a data fault alignment exception for the specified virtual address */
 void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr, int is_write,
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index e42d287..951fc5a 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -149,7 +149,7 @@ void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr, int is_write,
     /* the DFSR for an alignment fault depends on whether we're using
      * the LPAE long descriptor format, or the short descriptor format
      */
-    if (arm_regime_using_lpae_format(env, cpu_mmu_index(env, false))) {
+    if (arm_s1_regime_using_lpae_format(env, cpu_mmu_index(env, false))) {
         env->exception.fsr = 0x21;
     } else {
         env->exception.fsr = 0x1;
-- 
2.7.0

Re: [Qemu-devel] [PATCH v2] target-arm: Use the right MMU index in arm_regime_using_lpae_format

[Peter Maydell]

On 15 January 2016 at 10:37, Alvise Rigo <a.rigo@virtualopensystems.com> wrote:
> arm_regime_using_lpae_format checks whether the LPAE extension is used
> for stage 1 translation regimes. MMU indexes not exclusively of a stage 1
> regime won't work with this method.
>
> In case of ARMMMUIdx_S12NSE0 or ARMMMUIdx_S12NSE1, offset these values
> by ARMMMUIdx_S1NSE0 to get the right index indicating a stage 1
> translation regime.
>
> Rename also the function to arm_s1_regime_using_lpae_format and update
> the comments to reflect the change.
>
> Signed-off-by: Alvise Rigo <a.rigo@virtualopensystems.com>



Applied to target-arm.next, thanks.

-- PMM