ucall.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * ucall support. A ucall is a "hypercall to userspace".
 4 *
 5 * Copyright (C) 2021 Western Digital Corporation or its affiliates.
 6 */
 7
 8#include <linux/kvm.h>
 9
10#include "kvm_util.h"
11#include "processor.h"
12#include "sbi.h"
13
14void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
15{
16	struct kvm_run *run = vcpu->run;
17
18	if (run->exit_reason == KVM_EXIT_RISCV_SBI &&
19	    run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) {
20		switch (run->riscv_sbi.function_id) {
21		case KVM_RISCV_SELFTESTS_SBI_UCALL:
22			return (void *)run->riscv_sbi.args[0];
23		case KVM_RISCV_SELFTESTS_SBI_UNEXP:
24			vcpu_dump(stderr, vcpu, 2);
25			TEST_ASSERT(0, "Unexpected trap taken by guest");
26			break;
27		default:
28			break;
29		}
30	}
31	return NULL;
32}