KVM: move segment_base() into vmx.c

segment_base() is used only by vmx so move it there.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 68712bdf0407..8e2a24693be9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -634,6 +634,43 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
         return true;
 }
 
+static unsigned long segment_base(u16 selector)
+{
+        struct desc_ptr gdt;
+        struct desc_struct *d;
+        unsigned long table_base;
+        unsigned long v;
+
+        if (!(selector & ~3))
+                return 0;
+
+        native_store_gdt(&gdt);
+        table_base = gdt.address;
+
+        if (selector & 4) {           /* from ldt */
+                u16 ldt_selector = kvm_read_ldt();
+
+                if (!(ldt_selector & ~3))
+                        return 0;
+
+                table_base = segment_base(ldt_selector);
+        }
+        d = (struct desc_struct *)(table_base + (selector & ~7));
+        v = get_desc_base(d);
+#ifdef CONFIG_X86_64
+       if (d->s == 0 && (d->type == 2 || d->type == 9 || d->type == 11))
+               v |= ((unsigned long)((struct ldttss_desc64 *)d)->base3) << 32;
+#endif
+        return v;
+}
+
+static inline unsigned long kvm_read_tr_base(void)
+{
+        u16 tr;
+        asm("str %0" : "=g"(tr));
+        return segment_base(tr);
+}
+
 static void vmx_save_host_state(struct kvm_vcpu *vcpu)
 {
         struct vcpu_vmx *vmx = to_vmx(vcpu);