33 lines
783 B
C
33 lines
783 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ucall support. A ucall is a "hypercall to userspace".
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*
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* Copyright (C) 2019 Red Hat, Inc.
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*/
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#include "kvm_util.h"
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void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa)
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{
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}
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void ucall_arch_do_ucall(vm_vaddr_t uc)
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{
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/* Exit via DIAGNOSE 0x501 (normally used for breakpoints) */
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asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory");
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}
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void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
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{
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struct kvm_run *run = vcpu->run;
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if (run->exit_reason == KVM_EXIT_S390_SIEIC &&
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run->s390_sieic.icptcode == 4 &&
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(run->s390_sieic.ipa >> 8) == 0x83 && /* 0x83 means DIAGNOSE */
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(run->s390_sieic.ipb >> 16) == 0x501) {
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int reg = run->s390_sieic.ipa & 0xf;
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return (void *)run->s.regs.gprs[reg];
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}
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return NULL;
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}
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