[Qemu-devel] [PATCH 07/13] x86/cpuid: remove unnecessary kvm_trim function

[Andre Przywara]

Correct me if I am wrong, but kvm_trim looks like a really bloated
implementation of a bitwise AND. So remove this function and replace
it with the real stuff(TM).

Signed-off-by: Andre Przywara <address@hidden>
---
 target-i386/kvm.c |   27 ++++++---------------------
 1 files changed, 6 insertions(+), 21 deletions(-)

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 40f8303..f77e488 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -133,19 +133,6 @@ uint32_t kvm_arch_get_supported_cpuid(CPUState *env, 
uint32_t function, int reg)
 
 #endif
 
-static void kvm_trim_features(uint32_t *features, uint32_t supported)
-{
-    int i;
-    uint32_t mask;
-
-    for (i = 0; i < 32; ++i) {
-        mask = 1U << i;
-        if ((*features & mask) && !(supported & mask)) {
-            *features &= ~mask;
-        }
-    }
-}
-
 #ifdef CONFIG_KVM_PARA
 struct kvm_para_features {
         int cap;
@@ -191,18 +178,16 @@ int kvm_arch_init_vcpu(CPUState *env)
 
     env->mp_state = KVM_MP_STATE_RUNNABLE;
 
-    kvm_trim_features(&env->cpuid_features,
-        kvm_arch_get_supported_cpuid(env, 1, R_EDX));
+    env->cpuid_features &= kvm_arch_get_supported_cpuid(env, 1, R_EDX);
 
     i = env->cpuid_ext_features & CPUID_EXT_HYPERVISOR;
-    kvm_trim_features(&env->cpuid_ext_features,
-        kvm_arch_get_supported_cpuid(env, 1, R_ECX));
+    env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(env, 1, R_ECX);
     env->cpuid_ext_features |= i;
 
-    kvm_trim_features(&env->cpuid_ext2_features,
-        kvm_arch_get_supported_cpuid(env, 0x80000001, R_EDX));
-    kvm_trim_features(&env->cpuid_ext3_features,
-        kvm_arch_get_supported_cpuid(env, 0x80000001, R_ECX));
+    env->cpuid_ext2_features &= kvm_arch_get_supported_cpuid(env, 0x80000001,
+                                                             R_EDX);
+    env->cpuid_ext3_features &= kvm_arch_get_supported_cpuid(env, 0x80000001,
+                                                             R_ECX);
 
     cpuid_i = 0;
 
-- 
1.6.4