xen: use iret instruction all the time

Change iret implementation to not be dependent on direct-access vcpu
structure.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 5 insertions, 11 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 198db49106b2..c0388220cf97 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -890,7 +890,6 @@ void __init xen_setup_vcpu_info_placement(void)
                 pv_irq_ops.irq_disable = xen_irq_disable_direct;
                 pv_irq_ops.irq_enable = xen_irq_enable_direct;
                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
-                pv_cpu_ops.iret = xen_iret_direct;
         }
 }
 
@@ -994,7 +993,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = {
         .read_tsc = native_read_tsc,
         .read_pmc = native_read_pmc,
 
-        .iret = (void *)&hypercall_page[__HYPERVISOR_iret],
+        .iret = xen_iret,
         .irq_enable_syscall_ret = NULL,  /* never called */
 
         .load_tr_desc = paravirt_nop,
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 6b7190449d07..fe161ed4b01e 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -135,13 +135,8 @@ ENDPATCH(xen_restore_fl_direct)
         current stack state in whatever form its in, we keep things
         simple by only using a single register which is pushed/popped
         on the stack.
-
-        Non-direct iret could be done in the same way, but it would
-        require an annoying amount of code duplication.  We'll assume
-        that direct mode will be the common case once the hypervisor
-        support becomes commonplace.
  */
-ENTRY(xen_iret_direct)
+ENTRY(xen_iret)
         /* test eflags for special cases */
         testl $(X86_EFLAGS_VM | XEN_EFLAGS_NMI), 8(%esp)
         jnz hyper_iret
@@ -155,9 +150,9 @@ ENTRY(xen_iret_direct)
         GET_THREAD_INFO(%eax)
         movl TI_cpu(%eax),%eax
         movl __per_cpu_offset(,%eax,4),%eax
-        lea per_cpu__xen_vcpu_info(%eax),%eax
+        mov per_cpu__xen_vcpu(%eax),%eax
 #else
-        movl $per_cpu__xen_vcpu_info, %eax
+        movl per_cpu__xen_vcpu, %eax
 #endif
 
         /* check IF state we're restoring */
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index b02a909bfd4c..956a491ea998 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -63,5 +63,5 @@ DECL_ASM(void, xen_irq_disable_direct, void);
 DECL_ASM(unsigned long, xen_save_fl_direct, void);
 DECL_ASM(void, xen_restore_fl_direct, unsigned long);
 
-void xen_iret_direct(void);
+void xen_iret(void);
 #endif /* XEN_OPS_H */