diff options
author | Gleb Natapov | 2010-05-10 11:16:56 +0300 |
---|---|---|
committer | Avi Kivity | 2010-08-01 10:35:40 +0300 |
commit | 6d77dbfc88e37c9efd5c5dd18445cfe819ae17ea (patch) | |
tree | 96a3afb750d254a99dd43fa4730fd6ff187eb2a0 /arch/x86/kvm/x86.c | |
parent | 57bc24cfd655c912498983130326b312e0404db1 (diff) |
KVM: inject #UD if instruction emulation fails and exit to userspace
Do not kill VM when instruction emulation fails. Inject #UD and report
failure to userspace instead. Userspace may choose to reenter guest if
vcpu is in userspace (cpl == 3) in which case guest OS will kill
offending process and continue running.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r-- | arch/x86/kvm/x86.c | 43 |
1 files changed, 18 insertions, 25 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fc5611b4007f..ae9d6f3e5d0d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3639,24 +3639,6 @@ int emulator_set_dr(int dr, unsigned long value, struct kvm_vcpu *vcpu) return __kvm_set_dr(vcpu, dr, value); } -void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context) -{ - u8 opcodes[4]; - unsigned long rip = kvm_rip_read(vcpu); - unsigned long rip_linear; - - if (!printk_ratelimit()) - return; - - rip_linear = rip + get_segment_base(vcpu, VCPU_SREG_CS); - - kvm_read_guest_virt(rip_linear, (void *)opcodes, 4, vcpu, NULL); - - printk(KERN_ERR "emulation failed (%s) rip %lx %02x %02x %02x %02x\n", - context, rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]); -} -EXPORT_SYMBOL_GPL(kvm_report_emulation_failure); - static u64 mk_cr_64(u64 curr_cr, u32 new_val) { return (curr_cr & ~((1ULL << 32) - 1)) | new_val; @@ -3863,6 +3845,19 @@ static void inject_emulated_exception(struct kvm_vcpu *vcpu) kvm_queue_exception(vcpu, ctxt->exception); } +static int handle_emulation_failure(struct kvm_vcpu *vcpu) +{ + struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt; + + ++vcpu->stat.insn_emulation_fail; + trace_kvm_emulate_insn_failed(vcpu); + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; + vcpu->run->internal.ndata = 0; + kvm_queue_exception(vcpu, UD_VECTOR); + return EMULATE_FAIL; +} + int emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2, u16 error_code, @@ -3931,11 +3926,11 @@ int emulate_instruction(struct kvm_vcpu *vcpu, ++vcpu->stat.insn_emulation; if (r) { - ++vcpu->stat.insn_emulation_fail; - trace_kvm_emulate_insn_failed(vcpu); if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) return EMULATE_DONE; - return EMULATE_FAIL; + if (emulation_type & EMULTYPE_SKIP) + return EMULATE_FAIL; + return handle_emulation_failure(vcpu); } } @@ -3960,9 +3955,7 @@ restart: if (kvm_mmu_unprotect_page_virt(vcpu, cr2)) return EMULATE_DONE; - trace_kvm_emulate_insn_failed(vcpu); - kvm_report_emulation_failure(vcpu, "mmio"); - return EMULATE_FAIL; + return handle_emulation_failure(vcpu); } toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility); @@ -4798,7 +4791,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); r = emulate_instruction(vcpu, 0, 0, EMULTYPE_NO_DECODE); srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); - if (r == EMULATE_DO_MMIO) { + if (r != EMULATE_DONE) { r = 0; goto out; } |