33 lines
676 B
C
33 lines
676 B
C
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// 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) 2018, Red Hat, Inc.
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*/
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#include "kvm_util.h"
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#define UCALL_PIO_PORT ((uint16_t)0x1000)
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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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asm volatile("in %[port], %%al"
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: : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "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_IO && run->io.port == UCALL_PIO_PORT) {
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struct kvm_regs regs;
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vcpu_regs_get(vcpu, ®s);
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return (void *)regs.rdi;
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}
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return NULL;
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}
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