Commit 120c2c4f authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Refactor kvm_vcpu_do_singlestep() to remove out param 



Return the single-step emulation result directly instead of via an out
param.  Presumably at some point in the past kvm_vcpu_do_singlestep()
could be called with *r==EMULATE_USER_EXIT, but that is no longer the
case, i.e. all callers are happy to overwrite their own return variable.

Reviewed-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 22da61c9

arch/x86/kvm/x86.c

+6 −6
Original line number Diff line number Diff line
@@ -6474,7 +6474,7 @@ static int kvm_vcpu_check_hw_bp(unsigned long addr, u32 type, u32 dr7, 
	return dr6;

}



static void kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu, int *r)

static int kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu)

{

	struct kvm_run *kvm_run = vcpu->run;
@@ -6483,10 +6483,10 @@ static void kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu, int *r) 
		kvm_run->debug.arch.pc = vcpu->arch.singlestep_rip;

		kvm_run->debug.arch.exception = DB_VECTOR;

		kvm_run->exit_reason = KVM_EXIT_DEBUG;

		*r = EMULATE_USER_EXIT;

	} else {

		kvm_queue_exception_p(vcpu, DB_VECTOR, DR6_BS);

		return EMULATE_USER_EXIT;

	}

	kvm_queue_exception_p(vcpu, DB_VECTOR, DR6_BS);

	return EMULATE_DONE;

}



int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu)
@@ -6507,7 +6507,7 @@ int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu) 
	 * that sets the TF flag".

	 */

	if (unlikely(rflags & X86_EFLAGS_TF))

		kvm_vcpu_do_singlestep(vcpu, &r);

		r = kvm_vcpu_do_singlestep(vcpu);

	return r == EMULATE_DONE;

}

EXPORT_SYMBOL_GPL(kvm_skip_emulated_instruction);
@@ -6720,7 +6720,7 @@ restart: 
		    exception_type(ctxt->exception.vector) == EXCPT_TRAP) {

			kvm_rip_write(vcpu, ctxt->eip);

			if (r == EMULATE_DONE && ctxt->tf)

				kvm_vcpu_do_singlestep(vcpu, &r);

				r = kvm_vcpu_do_singlestep(vcpu);

			__kvm_set_rflags(vcpu, ctxt->eflags);

		}

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