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
sbi_ecall(int ext,int fid,unsigned long arg0,unsigned long arg1,unsigned long arg2,unsigned long arg3,unsigned long arg4,unsigned long arg5)13 struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
14 unsigned long arg1, unsigned long arg2,
15 unsigned long arg3, unsigned long arg4,
16 unsigned long arg5)
17 {
18 register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
19 register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
20 register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
21 register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
22 register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
23 register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
24 register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
25 register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
26 struct sbiret ret;
27
28 asm volatile (
29 "ecall"
30 : "+r" (a0), "+r" (a1)
31 : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
32 : "memory");
33 ret.error = a0;
34 ret.value = a1;
35
36 return ret;
37 }
38
ucall_arch_get_ucall(struct kvm_vcpu * vcpu)39 void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
40 {
41 struct kvm_run *run = vcpu->run;
42
43 if (run->exit_reason == KVM_EXIT_RISCV_SBI &&
44 run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) {
45 switch (run->riscv_sbi.function_id) {
46 case KVM_RISCV_SELFTESTS_SBI_UCALL:
47 return (void *)run->riscv_sbi.args[0];
48 case KVM_RISCV_SELFTESTS_SBI_UNEXP:
49 vcpu_dump(stderr, vcpu, 2);
50 TEST_ASSERT(0, "Unexpected trap taken by guest");
51 break;
52 default:
53 break;
54 }
55 }
56 return NULL;
57 }
58