x86/kvm/vmx: Get rid of segment_base() on 64-bit kernels

It was a bit buggy (it didn't list all segment types that needed
64-bit fixups), but the bug was irrelevant because it wasn't called
in any interesting context on 64-bit kernels and was only used for
data segents on 32-bit kernels.

To avoid confusion, make it explicitly 32-bit only.

Cc: Thomas Garnier <thgarnie@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3dbbf4ec471fe75610a7a4f9b145c589b4ca9122..3ddd72303fe4a37afc7f513397de129d66e7fbf3 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2057,6 +2057,12 @@ static bool update_transition_efer(struct vcpu_vmx *vmx, int efer_offset)
        }
 }
 
+#ifdef CONFIG_X86_32
+/*
+ * On 32-bit kernels, VM exits still load the FS and GS bases from the
+ * VMCS rather than the segment table.  KVM uses this helper to figure
+ * out the current bases to poke them into the VMCS before entry.
+ */
 static unsigned long segment_base(u16 selector)
 {
        struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
@@ -2079,12 +2085,9 @@ static unsigned long segment_base(u16 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;
 }
+#endif
 
 static void vmx_save_host_state(struct kvm_vcpu *vcpu)
 {