Commit 338dbc97 authored by Gleb Natapov's avatar Gleb Natapov Committed by Avi Kivity
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KVM: x86 emulator: make (get|set)_dr() callback return error if it fails 



Make (get|set)_dr() callback return error if it fails instead of
injecting exception behind emulator's back.

Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 0f12244f

arch/x86/kvm/emulate.c

+8 −3
Original line number Diff line number Diff line
@@ -3151,9 +3151,14 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
			goto done;

		}



		ops->set_dr(c->modrm_reg,c->regs[c->modrm_rm] &

			    ((ctxt->mode == X86EMUL_MODE_PROT64) ? ~0ULL : ~0U),

			ctxt->vcpu);

		if (ops->set_dr(c->modrm_reg, c->regs[c->modrm_rm] &

				((ctxt->mode == X86EMUL_MODE_PROT64) ?

				 ~0ULL : ~0U), ctxt->vcpu) < 0) {

			/* #UD condition is already handled by the code above */

			kvm_inject_gp(ctxt->vcpu, 0);

			goto done;

		}



		c->dst.type = OP_NONE;	/* no writeback */

		break;

	case 0x30:

arch/x86/kvm/x86.c

+37 −26
Original line number Diff line number Diff line
@@ -573,7 +573,7 @@ unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu) 
}

EXPORT_SYMBOL_GPL(kvm_get_cr8);



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

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

{

	switch (dr) {

	case 0 ... 3:
@@ -582,29 +582,21 @@ int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) 
			vcpu->arch.eff_db[dr] = val;

		break;

	case 4:

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

			kvm_queue_exception(vcpu, UD_VECTOR);

			return 1;

		}

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))

			return 1; /* #UD */

		/* fall through */

	case 6:

		if (val & 0xffffffff00000000ULL) {

			kvm_inject_gp(vcpu, 0);

			return 1;

		}

		if (val & 0xffffffff00000000ULL)

			return -1; /* #GP */

		vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1;

		break;

	case 5:

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

			kvm_queue_exception(vcpu, UD_VECTOR);

			return 1;

		}

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))

			return 1; /* #UD */

		/* fall through */

	default: /* 7 */

		if (val & 0xffffffff00000000ULL) {

			kvm_inject_gp(vcpu, 0);

			return 1;

		}

		if (val & 0xffffffff00000000ULL)

			return -1; /* #GP */

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

		if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {

			kvm_x86_ops->set_dr7(vcpu, vcpu->arch.dr7);
@@ -615,28 +607,37 @@ 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)

{

	int res;



	res = __kvm_set_dr(vcpu, dr, val);

	if (res > 0)

		kvm_queue_exception(vcpu, UD_VECTOR);

	else if (res < 0)

		kvm_inject_gp(vcpu, 0);



	return res;

}

EXPORT_SYMBOL_GPL(kvm_set_dr);



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

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

{

	switch (dr) {

	case 0 ... 3:

		*val = vcpu->arch.db[dr];

		break;

	case 4:

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

			kvm_queue_exception(vcpu, UD_VECTOR);

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))

			return 1;

		}

		/* fall through */

	case 6:

		*val = vcpu->arch.dr6;

		break;

	case 5:

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) {

			kvm_queue_exception(vcpu, UD_VECTOR);

		if (kvm_read_cr4_bits(vcpu, X86_CR4_DE))

			return 1;

		}

		/* fall through */

	default: /* 7 */

		*val = vcpu->arch.dr7;
@@ -645,6 +646,15 @@ int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val) 


	return 0;

}



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

{

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

		kvm_queue_exception(vcpu, UD_VECTOR);

		return 1;

	}

	return 0;

}

EXPORT_SYMBOL_GPL(kvm_get_dr);



static inline u32 bit(int bitno)
@@ -3619,12 +3629,13 @@ int emulate_clts(struct kvm_vcpu *vcpu) 


int emulator_get_dr(int dr, unsigned long *dest, struct kvm_vcpu *vcpu)

{

	return kvm_get_dr(vcpu, dr, dest);

	return _kvm_get_dr(vcpu, dr, dest);

}



int emulator_set_dr(int dr, unsigned long value, struct kvm_vcpu *vcpu)

{

	return kvm_set_dr(vcpu, dr, value);



	return __kvm_set_dr(vcpu, dr, value);

}



void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context)