KVM: x86 emulator: Fix task switch privilege checks

Currently, all task switches check privileges against the DPL of the
TSS. This is only correct for jmp/call to a TSS. If a task gate is used,
the DPL of this take gate is used for the check instead. Exceptions,
external interrupts and iret shouldn't perform any check.

[avi: kill kvm-kmod remnants]

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ca74c1dadf3a..490a1b1a255f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5655,15 +5655,15 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
         return 0;
 }
 
-int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
-                    bool has_error_code, u32 error_code)
+int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
+                    int reason, bool has_error_code, u32 error_code)
 {
         struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
         int ret;
 
         init_emulate_ctxt(vcpu);
 
-        ret = emulator_task_switch(ctxt, tss_selector, reason,
+        ret = emulator_task_switch(ctxt, tss_selector, idt_index, reason,
                                    has_error_code, error_code);
 
         if (ret)