X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Finclude%2Fpalacios%2Fvmm_lowlevel.h;h=eec0d91a29bda138054e1c64fc3a8d813ba19d88;hb=2cb41f7db5b9f89113432d6b3daff4807ba8e5f2;hp=331a3076b48df57445e223ab0de312e981c9ba73;hpb=ed8feff1d5dd6bf028cd5ba0960ec125505d7597;p=palacios.git

diff --git a/palacios/include/palacios/vmm_lowlevel.h b/palacios/include/palacios/vmm_lowlevel.h
index 331a307..eec0d91 100644
--- a/palacios/include/palacios/vmm_lowlevel.h
+++ b/palacios/include/palacios/vmm_lowlevel.h
@@ -69,11 +69,29 @@ struct sys_segment64 {
 static void __inline__ v3_cpuid(uint32_t target, 
 				uint32_t * eax, uint32_t * ebx, 
 				uint32_t * ecx, uint32_t * edx) {
+#ifdef __V3_64BIT__
+    // avoid rbx on -FPIC - gcc likes to own rbx even on 64 bit PIC code
     __asm__ __volatile__ (
+			  "pushq %%rbx\n\t"
+			  "movq %%rdi, %%rbx\n\t"
 			  "cpuid\n\t"
-			  : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx)
+			  "movq %%rbx, %%rdi\n\t"
+			  "popq %%rbx\n\t"
+			  : "=a" (*eax), "=D" (*ebx), "=c" (*ecx), "=d" (*edx)
 			  : "0" (target), "2" (*ecx)
 			  );
+#elif __V3_32BIT__
+    // 32 bit code compiled with -fPIC, cannot use ebx as an ouput reg. Fantastic.
+    __asm__ __volatile__ (
+			  "pushl %%ebx\n\t"
+			  "movl %%edi, %%ebx\n\t"
+			  "cpuid\n\t"
+			  "movl %%ebx, %%edi\n\t"
+			  "popl %%ebx\n\t"
+			  : "=a" (*eax), "=D" (*ebx), "=c" (*ecx), "=d" (*edx)
+			  : "0" (target), "2" (*ecx)
+			  );
+#endif
     return;
 }