diff mbox

[v5,05/13] target/arm: Remove redundant DIV detection for KVM

Message ID 1529699547-17044-6-git-send-email-alindsay@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Aaron Lindsay June 22, 2018, 8:32 p.m. UTC 
KVM implies V7VE, which implies ARM_DIV and THUMB_DIV. The conditional
detection here is therefore unnecessary. Because V7VE is already
unconditionally specified for all KVM hosts, ARM_DIV and THUMB_DIV are
already indirectly specified and do not need to be included here at all.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
---
 target/arm/kvm32.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

Comments

Peter Maydell June 28, 2018, 4:21 p.m. UTC | #1 
On 22 June 2018 at 21:32, Aaron Lindsay <alindsay@codeaurora.org> wrote:
> KVM implies V7VE, which implies ARM_DIV and THUMB_DIV. The conditional
> detection here is therefore unnecessary. Because V7VE is already
> unconditionally specified for all KVM hosts, ARM_DIV and THUMB_DIV are
> already indirectly specified and do not need to be included here at all.
>
> Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
> ---

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox

Patch

diff --git a/target/arm/kvm32.c b/target/arm/kvm32.c
index fb9ea37..4e91c11 100644
--- a/target/arm/kvm32.c
+++ b/target/arm/kvm32.c
@@ -36,7 +36,7 @@  bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
      * and then query that CPU for the relevant ID registers.
      */
     int i, ret, fdarray[3];
-    uint32_t midr, id_pfr0, id_isar0, mvfr1;
+    uint32_t midr, id_pfr0, mvfr1;
     uint64_t features = 0;
     /* Old kernels may not know about the PREFERRED_TARGET ioctl: however
      * we know these will only support creating one kind of guest CPU,
@@ -60,11 +60,6 @@  bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
         },
         {
             .id = KVM_REG_ARM | KVM_REG_SIZE_U32
-            | ENCODE_CP_REG(15, 0, 0, 0, 2, 0, 0),
-            .addr = (uintptr_t)&id_isar0,
-        },
-        {
-            .id = KVM_REG_ARM | KVM_REG_SIZE_U32
             | KVM_REG_ARM_VFP | KVM_REG_ARM_VFP_MVFR1,
             .addr = (uintptr_t)&mvfr1,
         },
@@ -106,18 +101,6 @@  bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
     set_feature(&features, ARM_FEATURE_VFP3);
     set_feature(&features, ARM_FEATURE_GENERIC_TIMER);
 
-    switch (extract32(id_isar0, 24, 4)) {
-    case 1:
-        set_feature(&features, ARM_FEATURE_THUMB_DIV);
-        break;
-    case 2:
-        set_feature(&features, ARM_FEATURE_ARM_DIV);
-        set_feature(&features, ARM_FEATURE_THUMB_DIV);
-        break;
-    default:
-        break;
-    }
-
     if (extract32(id_pfr0, 12, 4) == 1) {
         set_feature(&features, ARM_FEATURE_THUMB2EE);
     }