Re: [Qemu-arm] [Qemu-devel] [PATCH 03/10] target-i386: cpu: move xcc->kvm_required check to realize time

[Eduardo Habkost]

On Mon, Jun 06, 2016 at 05:16:45PM +0200, Igor Mammedov wrote:
> it will allow to drop custom cpu_x86_init() and use
> cpu_generic_init() insteadi, reducing cpu_x86_create()
> to a simple 3-liner.
> 
> Signed-off-by: Igor Mammedov <address@hidden>
> Eduardo Habkost <address@hidden>

This triggers an assert when trying to use -cpu host with TCG:

  # ./x86_64-softmmu/qemu-system-x86_64 -machine accel=tcg -cpu host -nographic
  qemu-system-x86_64: /root/qemu/target-i386/cpu.c:1558: host_x86_cpu_initfn: 
Assertion `(kvm_allowed)' failed.
  Aborted

I will squash the following fix in it:

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 3f886a5..dcbfa0b 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1555,16 +1555,17 @@ static void host_x86_cpu_initfn(Object *obj)
     CPUX86State *env = &cpu->env;
     KVMState *s = kvm_state;
 
-    assert(kvm_enabled());
-
     /* We can't fill the features array here because we don't know yet if
      * "migratable" is true or false.
      */
     cpu->host_features = true;
 
-    env->cpuid_level = kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
-    env->cpuid_xlevel = kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
-    env->cpuid_xlevel2 = kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
+    /* If KVM is disabled, x86_cpu_realizefn() will report an error later */
+    if (kvm_enabled()) {
+        env->cpuid_level = kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
+        env->cpuid_xlevel = kvm_arch_get_supported_cpuid(s, 0x80000000, 0, 
R_EAX);
+        env->cpuid_xlevel2 = kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, 
R_EAX);
+    }
 
     object_property_set_bool(OBJECT(cpu), true, "pmu", &error_abort);
 }

-- 
Eduardo