x86/paravirt, 64-bit: make load_gs_index() a paravirt operation

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 18 insertions, 4 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 70fe13a1c41d..07d69f262337 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -944,7 +944,7 @@ KPROBE_END(error_entry)
         
        /* Reload gs selector with exception handling */
        /* edi:  new selector */ 
-ENTRY(load_gs_index)
+ENTRY(native_load_gs_index)
         CFI_STARTPROC
         pushf
         CFI_ADJUST_CFA_OFFSET 8
@@ -958,7 +958,7 @@ gs_change:
         CFI_ADJUST_CFA_OFFSET -8
         ret
         CFI_ENDPROC
-ENDPROC(load_gs_index)
+ENDPROC(native_load_gs_index)
        
         .section __ex_table,"a"
         .align 8
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index b20c369cb89d..27819e3e4245 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -329,6 +329,9 @@ struct pv_cpu_ops pv_cpu_ops = {
         .store_idt = native_store_idt,
         .store_tr = native_store_tr,
         .load_tls = native_load_tls,
+#ifdef CONFIG_X86_64
+        .load_gs_index = native_load_gs_index,
+#endif
         .write_ldt_entry = native_write_ldt_entry,
         .write_gdt_entry = native_write_gdt_entry,
         .write_idt_entry = native_write_idt_entry,
diff --git a/include/asm-x86/elf.h b/include/asm-x86/elf.h
index 8f232dc5b5fe..7be4733c793e 100644
--- a/include/asm-x86/elf.h
+++ b/include/asm-x86/elf.h
@@ -83,9 +83,9 @@ extern unsigned int vdso_enabled;
         (((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
 
 #include <asm/processor.h>
+#include <asm/system.h>
 
 #ifdef CONFIG_X86_32
-#include <asm/system.h>         /* for savesegment */
 #include <asm/desc.h>
 
 #define elf_check_arch(x)       elf_check_arch_ia32(x)
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
index 3dc223da200b..6d8966f9d190 100644
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -115,6 +115,9 @@ struct pv_cpu_ops {
         void (*set_ldt)(const void *desc, unsigned entries);
         unsigned long (*store_tr)(void);
         void (*load_tls)(struct thread_struct *t, unsigned int cpu);
+#ifdef CONFIG_X86_64
+        void (*load_gs_index)(unsigned int idx);
+#endif
         void (*write_ldt_entry)(struct desc_struct *ldt, int entrynum,
                                 const void *desc);
         void (*write_gdt_entry)(struct desc_struct *,
@@ -845,6 +848,13 @@ static inline void load_TLS(struct thread_struct *t, unsigned cpu)
         PVOP_VCALL2(pv_cpu_ops.load_tls, t, cpu);
 }
 
+#ifdef CONFIG_X86_64
+static inline void load_gs_index(unsigned int gs)
+{
+        PVOP_VCALL1(pv_cpu_ops.load_gs_index, gs);
+}
+#endif
+
 static inline void write_ldt_entry(struct desc_struct *dt, int entry,
                                    const void *desc)
 {
diff --git a/include/asm-x86/system.h b/include/asm-x86/system.h
index f686aa6abfe9..c4946c5964bf 100644
--- a/include/asm-x86/system.h
+++ b/include/asm-x86/system.h
@@ -136,7 +136,7 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \
 #define set_base(ldt, base) _set_base(((char *)&(ldt)) , (base))
 #define set_limit(ldt, limit) _set_limit(((char *)&(ldt)) , ((limit)-1))
 
-extern void load_gs_index(unsigned);
+extern void native_load_gs_index(unsigned);
 
 /*
  * Load a segment. Fall back on loading the zero
@@ -282,6 +282,7 @@ static inline void native_wbinvd(void)
 #ifdef CONFIG_X86_64
 #define read_cr8()      (native_read_cr8())
 #define write_cr8(x)    (native_write_cr8(x))
+#define load_gs_index   native_load_gs_index
 #endif
 
 /* Clear the 'TS' bit */