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@xxxxxxxxxx>
Cc: Jim Mattson <jmattson@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 46420aaf1684..b1810a0edec3 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2059,6 +2059,12 @@ 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);
@@ -2081,12 +2087,9 @@ 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)
{
--
2.9.3
