diff --git a/sys/amd64/amd64/fpu.c b/sys/amd64/amd64/fpu.c
--- a/sys/amd64/amd64/fpu.c
+++ b/sys/amd64/amd64/fpu.c
@@ -79,7 +79,7 @@
 #define	fxrstor(addr)		__asm __volatile("fxrstor %0" : : "m" (*(addr)))
 #define	fxsave(addr)		__asm __volatile("fxsave %0" : "=m" (*(addr)))
 #define	ldmxcsr(csr)		__asm __volatile("ldmxcsr %0" : : "m" (csr))
-#define	stmxcsr(addr)		__asm __volatile("stmxcsr %0" : : "m" (*(addr)))
+#define	stmxcsr(addr)		__asm __volatile("stmxcsr %0" : "=m" (*(addr)))
 
 static __inline void
 xrstor32(char *addr, uint64_t mask)
diff --git a/sys/amd64/vmm/intel/vmx_cpufunc.h b/sys/amd64/vmm/intel/vmx_cpufunc.h
--- a/sys/amd64/vmm/intel/vmx_cpufunc.h
+++ b/sys/amd64/vmm/intel/vmx_cpufunc.h
@@ -137,10 +137,9 @@
 
 	__asm __volatile("vmread %[r], %[addr];"
 			 VMX_SET_ERROR_CODE
-			 : [error] "=r" (error)
-			 : [r] "r" (r), [addr] "m" (*addr)
+			 : [error] "=r" (error), [addr] "=m" (*addr)
+			 : [r] "r" (r)
 			 : "memory");
-
 	return (error);
 }