tools/testing/selftests/kvm/x86_64/flds_emulation.h

   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\n",
  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 */