x86/paravirt/xen: properly fill out the ldt ops

LTP testing showed that Xen does not properly implement
sys_modify_ldt().  This patch does the final little bits needed to
make the ldt work properly.

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

2 files changed, 22 insertions, 1 deletions

diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h
index a44c4dc70590..24a524f5e1a2 100644
--- a/include/asm-x86/desc.h
+++ b/include/asm-x86/desc.h
@@ -97,7 +97,15 @@ static inline int desc_empty(const void *ptr)
         native_write_gdt_entry(dt, entry, desc, type)
 #define write_idt_entry(dt, entry, g)           \
         native_write_idt_entry(dt, entry, g)
-#endif
+
+static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
+{
+}
+
+static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
+{
+}
+#endif  /* CONFIG_PARAVIRT */
 
 static inline void native_write_idt_entry(gate_desc *idt, int entry,
                                           const gate_desc *gate)
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
index fbbde93f12d6..db9b0647b346 100644
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -124,6 +124,9 @@ struct pv_cpu_ops {
                                 int entrynum, const void *desc, int size);
         void (*write_idt_entry)(gate_desc *,
                                 int entrynum, const gate_desc *gate);
+        void (*alloc_ldt)(struct desc_struct *ldt, unsigned entries);
+        void (*free_ldt)(struct desc_struct *ldt, unsigned entries);
+
         void (*load_sp0)(struct tss_struct *tss, struct thread_struct *t);
 
         void (*set_iopl_mask)(unsigned mask);
@@ -824,6 +827,16 @@ do {							\
         (aux) = __aux;                                  \
 } while (0)
 
+static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
+{
+        PVOP_VCALL2(pv_cpu_ops.alloc_ldt, ldt, entries);
+}
+
+static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
+{
+        PVOP_VCALL2(pv_cpu_ops.free_ldt, ldt, entries);
+}
+
 static inline void load_TR_desc(void)
 {
         PVOP_VCALL0(pv_cpu_ops.load_tr_desc);