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