[uq/master PATCH 1/7] target-i386: Eliminate CONFIG_KVM #ifdefs

Eduardo Habkost
2014-01-30T19:49:09Z

The compiler is already able to eliminate the kvm_arch_get_supported_cpuid()
calls in kvm_cpu_fill_host() and filter_features_for_kvm(), so we can
eliminate the CONFIG_KVM #ifdefs there.

Also, kvm_cpu_fill_host() and host_cpuid() don't need to check
CONFIG_KVM, as they don't have any KVM-specific function calls.

Tested to build successfully with CONFIG_KVM disabled, using the
following CFLAGS combinations: "-DNDEBUG", "-DNDEBUG -O', "-DNDEBUG
-O0", "-DNDEBUG -O1", "-DNDEBUG -O2".

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
Changes v2:
* Check for __i386__ on host_cpuid() so the code compiles properly
on non-x86 hosts.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>

Change v3:
* Don't add assert(kvm_enabled()) line, which is not necessary to help
the compiler (and wouldn't help it if using -DNDEBUG, anyway).
Reported-by: Richard Henderson <rth@twiddle.net>
* Commit message update
---
target-i386/cpu.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 1f30efd..8425212 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -374,7 +374,6 @@ void disable_kvm_pv_eoi(void)
void host_cpuid(uint32_t function, uint32_t count,
uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
{
-#if defined(CONFIG_KVM)
uint32_t vec[4];

#ifdef __x86_64__
@@ -382,7 +381,7 @@ void host_cpuid(uint32_t function, uint32_t count,
: "=a"(vec[0]), "=b"(vec[1]),
"=c"(vec[2]), "=d"(vec[3])
: "0"(function), "c"(count) : "cc");
-#else
+#elif defined(__i386__)
asm volatile("pusha \n\t"
"cpuid \n\t"
"mov %%eax, 0(%2) \n\t"
@@ -392,6 +391,8 @@ void host_cpuid(uint32_t function, uint32_t count,
"popa"
: : "a"(function), "c"(count), "S"(vec)
: "memory", "cc");
+#else
+ abort();
#endif

if (eax)
@@ -402,7 +403,6 @@ void host_cpuid(uint32_t function, uint32_t count,
*ecx = vec[2];
if (edx)
*edx = vec[3];
-#endif
}

#define iswhite(c) ((c) && ((c) <= ' ' || '~' < (c)))
@@ -1119,7 +1119,6 @@ void x86_cpu_compat_set_features(const char *cpu_model, FeatureWord w,
}
}

-#ifdef CONFIG_KVM
static int cpu_x86_fill_model_id(char *str)
{
uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
@@ -1134,7 +1133,6 @@ static int cpu_x86_fill_model_id(char *str)
}
return 0;
}
-#endif

/* Fill a x86_def_t struct with information about the host CPU, and
* the CPU features supported by the host hardware + host kernel
@@ -1143,7 +1141,6 @@ static int cpu_x86_fill_model_id(char *str)
*/
static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def)
{
-#ifdef CONFIG_KVM
KVMState *s = kvm_state;
uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;

@@ -1173,8 +1170,6 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def)
kvm_arch_get_supported_cpuid(s, wi->cpuid_eax, wi->cpuid_ecx,
wi->cpuid_reg);
}
-
-#endif /* CONFIG_KVM */
}

static int unavailable_host_feature(FeatureWordInfo *f, uint32_t mask)
@@ -1817,7 +1812,6 @@ CpuDefinitionInfoList *arch_query_cpu_definitions(Error **errp)
return cpu_list;
}

-#ifdef CONFIG_KVM
static void filter_features_for_kvm(X86CPU *cpu)
{
CPUX86State *env = &cpu->env;
@@ -1834,7 +1828,6 @@ static void filter_features_for_kvm(X86CPU *cpu)
cpu->filtered_features[w] = requested_features & ~env->features[w];
}
}
-#endif

static void cpu_x86_register(X86CPU *cpu, const char *name, Error **errp)
{
@@ -2545,9 +2538,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
"Host's CPU doesn't support requested features");
goto out;
}
-#ifdef CONFIG_KVM
filter_features_for_kvm(cpu);
-#endif
}

#ifndef CONFIG_USER_ONLY
--
1.8.4.2