- if (!boot_cpu_has(X86_FEATURE_SEP) ||
- HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) != 0) {
- clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP);
- clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP);
+ return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
+}
+
+void __cpuinit xen_enable_sysenter(void)
+{
+ extern void xen_sysenter_target(void);
+ int ret;
+ unsigned sysenter_feature;
+
+#ifdef CONFIG_X86_32
+ sysenter_feature = X86_FEATURE_SEP;
+#else
+ sysenter_feature = X86_FEATURE_SYSENTER32;
+#endif
+
+ if (!boot_cpu_has(sysenter_feature))
+ return;
+
+ ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
+ if(ret != 0)
+ setup_clear_cpu_cap(sysenter_feature);
+}
+
+void __cpuinit xen_enable_syscall(void)
+{
+#ifdef CONFIG_X86_64
+ int ret;
+ extern void xen_syscall_target(void);
+ extern void xen_syscall32_target(void);
+
+ ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
+ if (ret != 0) {
+ printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
+ /* Pretty fatal; 64-bit userspace has no other
+ mechanism for syscalls. */
+ }
+
+ if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
+ ret = register_callback(CALLBACKTYPE_syscall32,
+ xen_syscall32_target);
+ if (ret != 0)
+ setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);