Commit 996ff542 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86: move kvm_inject_gp up from kvm_set_dr to callers 



Push the injection of #GP up to the callers, so that they can just use
kvm_complete_insn_gp. __kvm_set_dr is pretty much what the callers can use
together with kvm_complete_insn_gp, so rename it to kvm_set_dr and drop
the old kvm_set_dr wrapper.

This also allows nested VMX code, which really wanted to use __kvm_set_dr,
to use the right function.

While at it, remove the kvm_require_dr() check from the SVM interception.
The APM states:

  All normal exception checks take precedence over the SVM intercepts.

which includes the CR4.DE=1 #UD.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 29d6ca41

arch/x86/kvm/svm/svm.c

+5 −8
Original line number Diff line number Diff line
@@ -2617,6 +2617,7 @@ static int dr_interception(struct vcpu_svm *svm) 
{

	int reg, dr;

	unsigned long val;

	int err = 0;



	if (svm->vcpu.guest_debug == 0) {

		/*
@@ -2634,20 +2635,16 @@ static int dr_interception(struct vcpu_svm *svm) 


	reg = svm->vmcb->control.exit_info_1 & SVM_EXITINFO_REG_MASK;

	dr = svm->vmcb->control.exit_code - SVM_EXIT_READ_DR0;



	if (dr >= 16) { /* mov to DRn  */

		if (!kvm_require_dr(&svm->vcpu, dr - 16))

			return 1;

		dr -= 16;

		val = kvm_register_read(&svm->vcpu, reg);

		kvm_set_dr(&svm->vcpu, dr - 16, val);

		err = kvm_set_dr(&svm->vcpu, dr, val);

	} else {

		if (!kvm_require_dr(&svm->vcpu, dr))

			return 1;

		kvm_get_dr(&svm->vcpu, dr, &val);

		kvm_register_write(&svm->vcpu, reg, val);

	}



	return kvm_skip_emulated_instruction(&svm->vcpu);

	return kvm_complete_insn_gp(&svm->vcpu, err);

}



static int cr8_write_interception(struct vcpu_svm *svm)

arch/x86/kvm/vmx/vmx.c

+10 −7
Original line number Diff line number Diff line
@@ -5095,6 +5095,7 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
{

	unsigned long exit_qualification;

	int dr, dr7, reg;

	int err = 1;



	exit_qualification = vmx_get_exit_qual(vcpu);

	dr = exit_qualification & DEBUG_REG_ACCESS_NUM;
@@ -5103,9 +5104,9 @@ static int handle_dr(struct kvm_vcpu *vcpu) 
	if (!kvm_require_dr(vcpu, dr))

		return 1;



	/* Do not handle if the CPL > 0, will trigger GP on re-entry */

	if (!kvm_require_cpl(vcpu, 0))

		return 1;

	if (kvm_x86_ops.get_cpl(vcpu) > 0)

		goto out;



	dr7 = vmcs_readl(GUEST_DR7);

	if (dr7 & DR7_GD) {

		/*
@@ -5144,11 +5145,13 @@ static int handle_dr(struct kvm_vcpu *vcpu) 


		kvm_get_dr(vcpu, dr, &val);

		kvm_register_write(vcpu, reg, val);

	} else

		if (kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg)))

			return 1;

		err = 0;

	} else {

		err = kvm_set_dr(vcpu, dr, kvm_register_readl(vcpu, reg));

	}



	return kvm_skip_emulated_instruction(vcpu);

out:

	return kvm_complete_insn_gp(vcpu, err);

}



static void vmx_sync_dirty_debug_regs(struct kvm_vcpu *vcpu)

arch/x86/kvm/x86.c

+5 −14
Original line number Diff line number Diff line
@@ -1143,7 +1143,7 @@ static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu) 
	return fixed;

}



static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)

int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)

{

	size_t size = ARRAY_SIZE(vcpu->arch.db);
@@ -1156,13 +1156,13 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) 
	case 4:

	case 6:

		if (!kvm_dr6_valid(val))

			return -1; /* #GP */

			return 1; /* #GP */

		vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);

		break;

	case 5:

	default: /* 7 */

		if (!kvm_dr7_valid(val))

			return -1; /* #GP */

			return 1; /* #GP */

		vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;

		kvm_update_dr7(vcpu);

		break;
@@ -1170,15 +1170,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) 


	return 0;

}



int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)

{

	if (__kvm_set_dr(vcpu, dr, val)) {

		kvm_inject_gp(vcpu, 0);

		return 1;

	}

	return 0;

}

EXPORT_SYMBOL_GPL(kvm_set_dr);



void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
@@ -6619,7 +6610,7 @@ static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, 
			   unsigned long value)

{



	return __kvm_set_dr(emul_to_vcpu(ctxt), dr, value);

	return kvm_set_dr(emul_to_vcpu(ctxt), dr, value);

}



static u64 mk_cr_64(u64 curr_cr, u32 new_val)
@@ -8664,7 +8655,7 @@ static void enter_smm(struct kvm_vcpu *vcpu) 
	dt.address = dt.size = 0;

	static_call(kvm_x86_set_idt)(vcpu, &dt);



	__kvm_set_dr(vcpu, 7, DR7_FIXED_1);

	kvm_set_dr(vcpu, 7, DR7_FIXED_1);



	cs.selector = (vcpu->arch.smbase >> 4) & 0xffff;

	cs.base = vcpu->arch.smbase;