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 */
15 static inline void flds(uint64_t address)
16 {
17 __asm__ __volatile__(FLDS_MEM_EAX :: "a"(address));
18 }
19
20 static 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, ®s);
48 regs.rip += 2;
49 vcpu_regs_set(vcpu, ®s);
50 }
51
52 #endif /* !SELFTEST_KVM_FLDS_EMULATION_H */
53
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