33 lines
783 B
C
33 lines
783 B
C
|
// 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_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
void ucall_arch_do_ucall(vm_vaddr_t uc)
|
||
|
|
{
|
||
|
|
/* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
|
||
|
|
asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory");
|
||
|
|
}
|
||
|
|
|
||
|
|
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;
|
||
|
|
}
|