diff options
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e3b3141db13c..8a90403272e2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1840,9 +1840,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu, struct kvm_run *run, unsigned long cr2, u16 error_code, - int no_decode) + int emulation_type) { int r; + struct decode_cache *c; vcpu->arch.mmio_fault_cr2 = cr2; kvm_x86_ops->cache_regs(vcpu); @@ -1850,7 +1851,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, vcpu->mmio_is_write = 0; vcpu->arch.pio.string = 0; - if (!no_decode) { + if (!(emulation_type & EMULTYPE_NO_DECODE)) { int cs_db, cs_l; kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); @@ -1884,6 +1885,16 @@ int emulate_instruction(struct kvm_vcpu *vcpu, get_segment_base(vcpu, VCPU_SREG_FS); r = x86_decode_insn(&vcpu->arch.emulate_ctxt, &emulate_ops); + + /* Reject the instructions other than VMCALL/VMMCALL when + * try to emulate invalid opcode */ + c = &vcpu->arch.emulate_ctxt.decode; + if ((emulation_type & EMULTYPE_TRAP_UD) && + (!(c->twobyte && c->b == 0x01 && + (c->modrm_reg == 0 || c->modrm_reg == 3) && + c->modrm_mod == 3 && c->modrm_rm == 1))) + return EMULATE_FAIL; + ++vcpu->stat.insn_emulation; if (r) { ++vcpu->stat.insn_emulation_fail; @@ -2640,7 +2651,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) vcpu->mmio_read_completed = 1; vcpu->mmio_needed = 0; r = emulate_instruction(vcpu, kvm_run, - vcpu->arch.mmio_fault_cr2, 0, 1); + vcpu->arch.mmio_fault_cr2, 0, + EMULTYPE_NO_DECODE); if (r == EMULATE_DO_MMIO) { /* * Read-modify-write. Back to userspace. |