diff options
| -rw-r--r-- | arch/x86/kvm/svm.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 18 | ||||
| -rw-r--r-- | include/asm-x86/kvm_host.h | 4 |
4 files changed, 20 insertions, 6 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 33f77b044c5..de755cb1431 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -942,7 +942,7 @@ static int ud_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { int er; - er = emulate_instruction(&svm->vcpu, kvm_run, 0, 0, 0); + er = emulate_instruction(&svm->vcpu, kvm_run, 0, 0, EMULTYPE_TRAP_UD); if (er != EMULATE_DONE) kvm_queue_exception(&svm->vcpu, UD_VECTOR); return 1; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3d251f894a8..ad36447e696 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1863,7 +1863,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) } if (is_invalid_opcode(intr_info)) { - er = emulate_instruction(vcpu, kvm_run, 0, 0, 0); + er = emulate_instruction(vcpu, kvm_run, 0, 0, EMULTYPE_TRAP_UD); if (er != EMULATE_DONE) kvm_queue_exception(vcpu, UD_VECTOR); return 1; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e3b3141db13..8a90403272e 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. diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h index 20597bc1674..4702b04b979 100644 --- a/include/asm-x86/kvm_host.h +++ b/include/asm-x86/kvm_host.h @@ -415,8 +415,10 @@ enum emulation_result { EMULATE_FAIL, /* can't emulate this instruction */ }; +#define EMULTYPE_NO_DECODE (1 << 0) +#define EMULTYPE_TRAP_UD (1 << 1) int emulate_instruction(struct kvm_vcpu *vcpu, struct kvm_run *run, - unsigned long cr2, u16 error_code, int no_decode); + unsigned long cr2, u16 error_code, int emulation_type); void kvm_report_emulation_failure(struct kvm_vcpu *cvpu, const char *context); void realmode_lgdt(struct kvm_vcpu *vcpu, u16 size, unsigned long address); void realmode_lidt(struct kvm_vcpu *vcpu, u16 size, unsigned long address); |