KVM: X86: Fix single-step with KVM_SET_GUEST_DEBUG

When single-step triggered with KVM_SET_GUEST_DEBUG, we should fill in the pc
value with current linear RIP rather than the cached singlestep address.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20200505205000.188252-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

@@ -6662,7 +6662,7 @@ static int kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu)
 
 	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
 		kvm_run->debug.arch.dr6 = DR6_BS | DR6_FIXED_1 | DR6_RTM;
-		kvm_run->debug.arch.pc = vcpu->arch.singlestep_rip;
+		kvm_run->debug.arch.pc = kvm_get_linear_rip(vcpu);
 		kvm_run->debug.arch.exception = DB_VECTOR;
 		kvm_run->exit_reason = KVM_EXIT_DEBUG;
 		return 0;