tools/testing/selftests/kvm/lib/s390/ucall.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/kvm/lib/s390/ucall.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/kvm/lib/s390/ucall.c
Extension
.c
Size
551 bytes
Lines
23
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// 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;
}

Annotation

Implementation Notes