KVM: x86: Add kvm_is_linear_rip

Based on Gleb's suggestion: Add a helper kvm_is_linear_rip that matches
a given linear RIP against the current one. Use this for guest
single-stepping, more users will follow.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d46e791..502fff1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -362,8 +362,8 @@
 	u64 *mce_banks;
 
 	/* used for guest single stepping over the given code position */
-	u16 singlestep_cs;
 	unsigned long singlestep_rip;
+
 	/* fields used by HYPER-V emulation */
 	u64 hv_vapic;
 };
@@ -820,4 +820,6 @@
 void kvm_define_shared_msr(unsigned index, u32 msr);
 void kvm_set_shared_msr(unsigned index, u64 val, u64 mask);
 
+bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip);
+
 #endif /* _ASM_X86_KVM_HOST_H */