static int kvm_riscv_vcpu_set_reg_core()

in kvm/vcpu.c [266:299]

• 30 lines of code
• 9 McCabe index (conditional complexity)

static int kvm_riscv_vcpu_set_reg_core(struct kvm_vcpu *vcpu,
				       const struct kvm_one_reg *reg)
{
	struct kvm_cpu_context *cntx = &vcpu->arch.guest_context;
	unsigned long __user *uaddr =
			(unsigned long __user *)(unsigned long)reg->addr;
	unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK |
					    KVM_REG_SIZE_MASK |
					    KVM_REG_RISCV_CORE);
	unsigned long reg_val;

	if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
		return -EINVAL;
	if (reg_num >= sizeof(struct kvm_riscv_core) / sizeof(unsigned long))
		return -EINVAL;

	if (copy_from_user(&reg_val, uaddr, KVM_REG_SIZE(reg->id)))
		return -EFAULT;

	if (reg_num == KVM_REG_RISCV_CORE_REG(regs.pc))
		cntx->sepc = reg_val;
	else if (KVM_REG_RISCV_CORE_REG(regs.pc) < reg_num &&
		 reg_num <= KVM_REG_RISCV_CORE_REG(regs.t6))
		((unsigned long *)cntx)[reg_num] = reg_val;
	else if (reg_num == KVM_REG_RISCV_CORE_REG(mode)) {
		if (reg_val == KVM_RISCV_MODE_S)
			cntx->sstatus |= SR_SPP;
		else
			cntx->sstatus &= ~SR_SPP;
	} else
		return -EINVAL;

	return 0;
}