case KVM_REG_ARM_CORE_REG()

in kvm/guest.c [132:236]

• 73 lines of code
• 24 McCabe index (conditional complexity)

	case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
	     KVM_REG_ARM_CORE_REG(regs.regs[30]):
		off -= KVM_REG_ARM_CORE_REG(regs.regs[0]);
		off /= 2;
		return &vcpu->arch.ctxt.regs.regs[off];

	case KVM_REG_ARM_CORE_REG(regs.sp):
		return &vcpu->arch.ctxt.regs.sp;

	case KVM_REG_ARM_CORE_REG(regs.pc):
		return &vcpu->arch.ctxt.regs.pc;

	case KVM_REG_ARM_CORE_REG(regs.pstate):
		return &vcpu->arch.ctxt.regs.pstate;

	case KVM_REG_ARM_CORE_REG(sp_el1):
		return __ctxt_sys_reg(&vcpu->arch.ctxt, SP_EL1);

	case KVM_REG_ARM_CORE_REG(elr_el1):
		return __ctxt_sys_reg(&vcpu->arch.ctxt, ELR_EL1);

	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_EL1]):
		return __ctxt_sys_reg(&vcpu->arch.ctxt, SPSR_EL1);

	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_ABT]):
		return &vcpu->arch.ctxt.spsr_abt;

	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_UND]):
		return &vcpu->arch.ctxt.spsr_und;

	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_IRQ]):
		return &vcpu->arch.ctxt.spsr_irq;

	case KVM_REG_ARM_CORE_REG(spsr[KVM_SPSR_FIQ]):
		return &vcpu->arch.ctxt.spsr_fiq;

	case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
	     KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
		off -= KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]);
		off /= 4;
		return &vcpu->arch.ctxt.fp_regs.vregs[off];

	case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
		return &vcpu->arch.ctxt.fp_regs.fpsr;

	case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
		return &vcpu->arch.ctxt.fp_regs.fpcr;

	default:
		return NULL;
	}
}

static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
	/*
	 * Because the kvm_regs structure is a mix of 32, 64 and
	 * 128bit fields, we index it as if it was a 32bit
	 * array. Hence below, nr_regs is the number of entries, and
	 * off the index in the "array".
	 */
	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
	int nr_regs = sizeof(struct kvm_regs) / sizeof(__u32);
	void *addr;
	u32 off;

	/* Our ID is an index into the kvm_regs struct. */
	off = core_reg_offset_from_id(reg->id);
	if (off >= nr_regs ||
	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
		return -ENOENT;

	addr = core_reg_addr(vcpu, reg);
	if (!addr)
		return -EINVAL;

	if (copy_to_user(uaddr, addr, KVM_REG_SIZE(reg->id)))
		return -EFAULT;

	return 0;
}

static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
	__u32 __user *uaddr = (__u32 __user *)(unsigned long)reg->addr;
	int nr_regs = sizeof(struct kvm_regs) / sizeof(__u32);
	__uint128_t tmp;
	void *valp = &tmp, *addr;
	u64 off;
	int err = 0;

	/* Our ID is an index into the kvm_regs struct. */
	off = core_reg_offset_from_id(reg->id);
	if (off >= nr_regs ||
	    (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
		return -ENOENT;

	addr = core_reg_addr(vcpu, reg);
	if (!addr)
		return -EINVAL;

	if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
		return -EINVAL;

	if (copy_from_user(valp, uaddr, KVM_REG_SIZE(reg->id))) {