linuxdebug/tools/testing/selftests/kvm/lib/riscv/ucall.c

99 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* ucall support. A ucall is a "hypercall to userspace".
*
* Copyright (C) 2021 Western Digital Corporation or its affiliates.
*/
#include <linux/kvm.h>
#include "kvm_util.h"
#include "processor.h"
void ucall_init(struct kvm_vm *vm, void *arg)
{
}
void ucall_uninit(struct kvm_vm *vm)
{
}
struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
unsigned long arg1, unsigned long arg2,
unsigned long arg3, unsigned long arg4,
unsigned long arg5)
{
register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
struct sbiret ret;
asm volatile (
"ecall"
: "+r" (a0), "+r" (a1)
: "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
: "memory");
ret.error = a0;
ret.value = a1;
return ret;
}
void ucall(uint64_t cmd, int nargs, ...)
{
struct ucall uc = {
.cmd = cmd,
};
va_list va;
int i;
nargs = min(nargs, UCALL_MAX_ARGS);
va_start(va, nargs);
for (i = 0; i < nargs; ++i)
uc.args[i] = va_arg(va, uint64_t);
va_end(va);
sbi_ecall(KVM_RISCV_SELFTESTS_SBI_EXT,
KVM_RISCV_SELFTESTS_SBI_UCALL,
(vm_vaddr_t)&uc, 0, 0, 0, 0, 0);
}
uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
{
struct kvm_run *run = vcpu->run;
struct ucall ucall = {};
if (uc)
memset(uc, 0, sizeof(*uc));
if (run->exit_reason == KVM_EXIT_RISCV_SBI &&
run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) {
switch (run->riscv_sbi.function_id) {
case KVM_RISCV_SELFTESTS_SBI_UCALL:
memcpy(&ucall,
addr_gva2hva(vcpu->vm, run->riscv_sbi.args[0]),
sizeof(ucall));
vcpu_run_complete_io(vcpu);
if (uc)
memcpy(uc, &ucall, sizeof(ucall));
break;
case KVM_RISCV_SELFTESTS_SBI_UNEXP:
vcpu_dump(stderr, vcpu, 2);
TEST_ASSERT(0, "Unexpected trap taken by guest");
break;
default:
break;
}
}
return ucall.cmd;
}