| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * ucall support. A ucall is a "hypercall to userspace". |
| * |
| * Copyright (C) 2018, Red Hat, Inc. |
| */ |
| #include "kvm_util.h" |
| |
| #define UCALL_PIO_PORT ((uint16_t)0x1000) |
| |
| void ucall_arch_init(struct kvm_vm *vm, vm_paddr_t mmio_gpa) |
| { |
| } |
| |
| void ucall_arch_do_ucall(vm_vaddr_t uc) |
| { |
| asm volatile("in %[port], %%al" |
| : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory"); |
| } |
| |
| void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) |
| { |
| struct kvm_run *run = vcpu->run; |
| |
| if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) { |
| struct kvm_regs regs; |
| |
| vcpu_regs_get(vcpu, ®s); |
| return (void *)regs.rdi; |
| } |
| return NULL; |
| } |
