static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
				gva_t addr, void *val, unsigned int bytes,
				struct x86_exception *exception)
{
	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
	unsigned offset;
	int ret;

	/* Inline kvm_read_guest_virt_helper for speed.  */
	gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access|PFERR_FETCH_MASK,
						    exception);
	if (unlikely(gpa == UNMAPPED_GVA))
		return X86EMUL_PROPAGATE_FAULT;

	offset = addr & (PAGE_SIZE-1);
	if (WARN_ON(offset + bytes > PAGE_SIZE))
		bytes = (unsigned)PAGE_SIZE - offset;
	ret = kvm_read_guest_page(vcpu->kvm, gpa >> PAGE_SHIFT, val,
				  offset, bytes);
	if (unlikely(ret < 0))
		return X86EMUL_IO_NEEDED;

	return X86EMUL_CONTINUE;
}
Unknown