1/* SPDX-License-Identifier: GPL-2.0-only */
2#ifndef SELFTEST_KVM_FLDS_EMULATION_H
3#define SELFTEST_KVM_FLDS_EMULATION_H
4
5#include "kvm_util.h"
6
7#define FLDS_MEM_EAX ".byte 0xd9, 0x00"
8
9/*
10 * flds is an instruction that the KVM instruction emulator is known not to
11 * support. This can be used in guest code along with a mechanism to force
12 * KVM to emulate the instruction (e.g. by providing an MMIO address) to
13 * exercise emulation failures.
14 */
15static inline void flds(uint64_t address)
16{
17	__asm__ __volatile__(FLDS_MEM_EAX :: "a"(address));
18}
19
20static inline void handle_flds_emulation_failure_exit(struct kvm_vcpu *vcpu)
21{
22	struct kvm_run *run = vcpu->run;
23	struct kvm_regs regs;
24	uint8_t *insn_bytes;
25	uint64_t flags;
26
27	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR);
28
29	TEST_ASSERT(run->emulation_failure.suberror == KVM_INTERNAL_ERROR_EMULATION,
30		    "Unexpected suberror: %u",
31		    run->emulation_failure.suberror);
32
33	flags = run->emulation_failure.flags;
34	TEST_ASSERT(run->emulation_failure.ndata >= 3 &&
35		    flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES,
36		    "run->emulation_failure is missing instruction bytes");
37
38	TEST_ASSERT(run->emulation_failure.insn_size >= 2,
39		    "Expected a 2-byte opcode for 'flds', got %d bytes",
40		    run->emulation_failure.insn_size);
41
42	insn_bytes = run->emulation_failure.insn_bytes;
43	TEST_ASSERT(insn_bytes[0] == 0xd9 && insn_bytes[1] == 0,
44		    "Expected 'flds [eax]', opcode '0xd9 0x00', got opcode 0x%02x 0x%02x",
45		    insn_bytes[0], insn_bytes[1]);
46
47	vcpu_regs_get(vcpu, &regs);
48	regs.rip += 2;
49	vcpu_regs_set(vcpu, &regs);
50}
51
52#endif /* !SELFTEST_KVM_FLDS_EMULATION_H */
53