KVM: x86 emulator: Allow accessing IDT via emulator ops

The patch adds a new member get_idt() to x86_emulate_ops.
It also adds a function to get the idt in order to be used by the emulator.

This is needed for real mode interrupt injection and the emulation of int
instructions.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/kvm_emulate.h

@@ -139,6 +139,7 @@ struct x86_emulate_ops {
 	void (*set_segment_selector)(u16 sel, int seg, struct kvm_vcpu *vcpu);
 	unsigned long (*get_cached_segment_base)(int seg, struct kvm_vcpu *vcpu);
 	void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu);
+	void (*get_idt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu);
 	ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu);
 	int (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu);
 	int (*cpl)(struct kvm_vcpu *vcpu);

arch/x86/kvm/x86.c

@@ -3790,6 +3790,11 @@ static void emulator_get_gdt(struct desc_ptr *dt, struct kvm_vcpu *vcpu)
 	kvm_x86_ops->get_gdt(vcpu, dt);
 }
 
+static void emulator_get_idt(struct desc_ptr *dt, struct kvm_vcpu *vcpu)
+{
+	kvm_x86_ops->get_idt(vcpu, dt);
+}
+
 static unsigned long emulator_get_cached_segment_base(int seg,
 						      struct kvm_vcpu *vcpu)
 {
@@ -3883,6 +3888,7 @@ static struct x86_emulate_ops emulate_ops = {
 	.set_segment_selector = emulator_set_segment_selector,
 	.get_cached_segment_base = emulator_get_cached_segment_base,
 	.get_gdt             = emulator_get_gdt,
+	.get_idt	     = emulator_get_idt,
 	.get_cr              = emulator_get_cr,
 	.set_cr              = emulator_set_cr,
 	.cpl                 = emulator_get_cpl,