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// SPDX-License-Identifier: GPL-2.0
/*
* ucall support. A ucall is a "hypercall to userspace".
*
* Copyright (C) 2019 Red Hat, Inc.
*/
#include "kvm_util.h"
void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
if (run->exit_reason == KVM_EXIT_S390_SIEIC &&
run->s390_sieic.icptcode == 4 &&
(run->s390_sieic.ipa >> 8) == 0x83 && /* 0x83 means DIAGNOSE */
(run->s390_sieic.ipb >> 16) == 0x501) {
int reg = run->s390_sieic.ipa & 0xf;
return (void *)run->s.regs.gprs[reg];
}
return NULL;
}