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Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/flds_emulation.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/flds_emulation.h b/tools/testing/selftests/kvm/x86_64/flds_emulation.h new file mode 100644 index 000000000000..37b1a9f52864 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/flds_emulation.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_KVM_FLDS_EMULATION_H +#define SELFTEST_KVM_FLDS_EMULATION_H + +#include "kvm_util.h" + +#define FLDS_MEM_EAX ".byte 0xd9, 0x00" + +/* + * flds is an instruction that the KVM instruction emulator is known not to + * support. This can be used in guest code along with a mechanism to force + * KVM to emulate the instruction (e.g. by providing an MMIO address) to + * exercise emulation failures. + */ +static inline void flds(uint64_t address) +{ + __asm__ __volatile__(FLDS_MEM_EAX :: "a"(address)); +} + +static inline void handle_flds_emulation_failure_exit(struct kvm_vcpu *vcpu) +{ + struct kvm_run *run = vcpu->run; + struct kvm_regs regs; + uint8_t *insn_bytes; + uint64_t flags; + + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_INTERNAL_ERROR); + + TEST_ASSERT(run->emulation_failure.suberror == KVM_INTERNAL_ERROR_EMULATION, + "Unexpected suberror: %u", + run->emulation_failure.suberror); + + flags = run->emulation_failure.flags; + TEST_ASSERT(run->emulation_failure.ndata >= 3 && + flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES, + "run->emulation_failure is missing instruction bytes"); + + TEST_ASSERT(run->emulation_failure.insn_size >= 2, + "Expected a 2-byte opcode for 'flds', got %d bytes", + run->emulation_failure.insn_size); + + insn_bytes = run->emulation_failure.insn_bytes; + TEST_ASSERT(insn_bytes[0] == 0xd9 && insn_bytes[1] == 0, + "Expected 'flds [eax]', opcode '0xd9 0x00', got opcode 0x%02x 0x%02x", + insn_bytes[0], insn_bytes[1]); + + vcpu_regs_get(vcpu, ®s); + regs.rip += 2; + vcpu_regs_set(vcpu, ®s); +} + +#endif /* !SELFTEST_KVM_FLDS_EMULATION_H */ |