KVM: SVM: move has_svm() code to asm/virtext.h

Use a trick to keep the printk()s on has_svm() working as before. gcc
will take care of not generating code for the 'msg' stuff when the
function is called with a NULL msg argument.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h
index 6bcf0acb4ef1fd0ad19f37ee6f39bdf13d0ef35e..6f0d409c3682078ae81fbdfdf1d2287cd4679458 100644 (file)
--- a/arch/x86/include/asm/virtext.h
+++ b/arch/x86/include/asm/virtext.h
@@ -19,6 +19,7 @@
 #include <asm/system.h>
 
 #include <asm/vmx.h>
+#include <asm/svm.h>
 
 /*
  * VMX functions:
@@ -66,4 +67,44 @@ static inline void cpu_emergency_vmxoff(void)
                __cpu_emergency_vmxoff();
 }
 
+
+
+
+/*
+ * SVM functions:
+ */
+
+/** Check if the CPU has SVM support
+ *
+ * You can use the 'msg' arg to get a message describing the problem,
+ * if the function returns zero. Simply pass NULL if you are not interested
+ * on the messages; gcc should take care of not generating code for
+ * the messages on this case.
+ */
+static inline int cpu_has_svm(const char **msg)
+{
+       uint32_t eax, ebx, ecx, edx;
+
+       if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
+               if (msg)
+                       *msg = "not amd";
+               return 0;
+       }
+
+       cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
+       if (eax < SVM_CPUID_FUNC) {
+               if (msg)
+                       *msg = "can't execute cpuid_8000000a";
+               return 0;
+       }
+
+       cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
+       if (!(ecx & (1 << SVM_CPUID_FEATURE_SHIFT))) {
+               if (msg)
+                       *msg = "svm not available";
+               return 0;
+       }
+       return 1;
+}
+
 #endif /* _ASM_X86_VIRTEX_H */

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f0ad4d4217e44a974d915d3a1881614dc0bc6975..0667c6d13d30c9fc91b587015599da7d2f11b083 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -28,6 +28,8 @@
 
 #include <asm/desc.h>
 
+#include <asm/virtext.h>
+
 #define __ex(x) __kvm_handle_fault_on_reboot(x)
 
 MODULE_AUTHOR("Qumranet");
@@ -245,24 +247,13 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
 
 static int has_svm(void)
 {
-       uint32_t eax, ebx, ecx, edx;
-
-       if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
-               printk(KERN_INFO "has_svm: not amd\n");
-               return 0;
-       }
+       const char *msg;
 
-       cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
-       if (eax < SVM_CPUID_FUNC) {
-               printk(KERN_INFO "has_svm: can't execute cpuid_8000000a\n");
+       if (!cpu_has_svm(&msg)) {
+               printk(KERN_INFO "has_svn: %s\n", msg);
                return 0;
        }
 
-       cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
-       if (!(ecx & (1 << SVM_CPUID_FEATURE_SHIFT))) {
-               printk(KERN_DEBUG "has_svm: svm not available\n");
-               return 0;
-       }
        return 1;
 }