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path: root/sys/linux/dev_kvm_riscv64.txt
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# Copyright 2026 syzkaller project authors. All rights reserved.
# Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.

# RISCV64-specific KVM syscall declarations.

meta arches["riscv64"]

include <uapi/linux/kvm.h>

ioctl$KVM_SET_GUEST_DEBUG_riscv64(fd fd_kvmcpu, cmd const[KVM_SET_GUEST_DEBUG], arg ptr[in, kvm_guest_debug[kvm_guest_debug_arch_riscv64]])

kvm_guest_debug_arch_riscv64 {
	reg	array[int64, 8]
}

syz_kvm_setup_cpu$riscv64(fd fd_kvmvm, cpufd fd_kvmcpu, usermem vma[24], text ptr[in, array[kvm_text_riscv64, 1]], ntext len[text], flags const[0], opts ptr[in, array[kvm_setup_opt_riscv64, 1]], nopt len[opts])

kvm_setup_opt_riscv64 [
# unions need at least 2 fields, but we have only 1 now, but we want to have it as union for future extention
	featur1	kvm_setup_opt_riscv64_feature
	featur2	kvm_setup_opt_riscv64_feature
]

kvm_setup_opt_riscv64_feature {
	typ	const[1, int64]
	val	int64
}

kvm_text_riscv64 {
	typ	const[0, intptr]
	text	ptr[in, text[riscv64]]
	size	len[text, intptr]
}

# kvm_syz_vm is a VM handler used by syzos-related pseudo-syscalls. It is actually an opaque pointer under the hood.
resource kvm_syz_vm$riscv64[int64]

# Map the given memory into the VM and set up syzos there.
syz_kvm_setup_syzos_vm$riscv64(fd fd_kvmvm, usermem vma[1024]) kvm_syz_vm$riscv64

# Create a VCPU inside a kvm_syz_vm VM.
# Prohibit flattening the input arguments, so that it is easier to reason about them.
syz_kvm_add_vcpu$riscv64(vm kvm_syz_vm$riscv64, text ptr[in, kvm_text_syzos_riscv64], opts ptr[in, array[kvm_setup_opt_riscv64, 1]], nopt len[opts]) fd_kvmcpu (no_squash)

kvm_text_syzos_riscv64 {
	typ	const[0, intptr]
	text	ptr[in, array[syzos_api_call$riscv64, 1:32]]
	size	bytesize[text, int64]
}

type syzos_api$riscv64[NUM, PAYLOAD] {
	call	const[NUM, int64]
	size	bytesize[parent, int64]
	payload	PAYLOAD
}

syzos_api_code$riscv64 {
	insns	text[riscv64]
	ret	const[0x8067, int32]
} [packed]

syzos_api_csrr {
	arg_reg	riscv64_csr_or_any
}

syzos_api_csrw {
	arg_reg		riscv64_csr_or_any
	arg_value	int64
}

riscv64_csr_or_any [
	valid	flags[riscv64_csr, int64]
	any	int64
]

# Table 5 in https://docs.riscv.org/reference/isa/_attachments/riscv-privileged.pdf .
# Currently, only 11 CSRS are supported in Linux-6.19. See
# https://elixir.bootlin.com/linux/v6.19-rc5/source/arch/riscv/include/uapi/asm/kvm.h#L75 .
riscv64_csr = 0x100, 0x104, 0x105, 0x140, 0x141, 0x142, 0x143, 0x144, 0x180, 0x106, 0x10a

syzos_api_call$riscv64 [
	uexit	syzos_api$riscv64[0, intptr]
	code	syzos_api$riscv64[10, syzos_api_code$riscv64]
	csrr	syzos_api$riscv64[100, syzos_api_csrr]
	csrw	syzos_api$riscv64[101, syzos_api_csrw]
] [varlen]

# Test assertions, will not be used by the fuzzer.
syz_kvm_assert_reg$riscv64(fd fd_kvmcpu, reg int64, value int64) (no_generate)
syz_kvm_assert_syzos_uexit$riscv64(cpufd fd_kvmcpu, run kvm_run_ptr, exitcode int64) (no_generate)
syz_kvm_assert_syzos_kvm_exit$riscv64(run kvm_run_ptr, exitcode int64) (no_generate)