Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH v2 3/7] x86/kvm/vmx: Get rid of segment_base() on 64-bit kernels | Date | Tue, 21 Feb 2017 11:14:10 -0800 |
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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 code and data segments 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> --- 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
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