diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/svm.c | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 908ec61895ce..468ff6e721ce 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -47,6 +47,7 @@ MODULE_LICENSE("GPL"); #define SVM_FEATURE_NPT (1 << 0) #define SVM_FEATURE_LBRV (1 << 1) #define SVM_FEATURE_SVML (1 << 2) +#define SVM_FEATURE_NRIP (1 << 3) #define SVM_FEATURE_PAUSE_FILTER (1 << 10) #define NESTED_EXIT_HOST 0 /* Exit handled on host level */ @@ -110,6 +111,9 @@ struct vcpu_svm { struct nested_state nested; bool nmi_singlestep; + + unsigned int3_injected; + unsigned long int3_rip; }; /* enable NPT for AMD64 and X86 with PAE */ @@ -291,6 +295,22 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr, if (nested_svm_check_exception(svm, nr, has_error_code, error_code)) return; + if (nr == BP_VECTOR && !svm_has(SVM_FEATURE_NRIP)) { + unsigned long rip, old_rip = kvm_rip_read(&svm->vcpu); + + /* + * For guest debugging where we have to reinject #BP if some + * INT3 is guest-owned: + * Emulate nRIP by moving RIP forward. Will fail if injection + * raises a fault that is not intercepted. Still better than + * failing in all cases. + */ + skip_emulated_instruction(&svm->vcpu); + rip = kvm_rip_read(&svm->vcpu); + svm->int3_rip = rip + svm->vmcb->save.cs.base; + svm->int3_injected = rip - old_rip; + } + svm->vmcb->control.event_inj = nr | SVM_EVTINJ_VALID | (has_error_code ? SVM_EVTINJ_VALID_ERR : 0) @@ -2701,6 +2721,9 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) u8 vector; int type; u32 exitintinfo = svm->vmcb->control.exit_int_info; + unsigned int3_injected = svm->int3_injected; + + svm->int3_injected = 0; if (svm->vcpu.arch.hflags & HF_IRET_MASK) svm->vcpu.arch.hflags &= ~(HF_NMI_MASK | HF_IRET_MASK); @@ -2720,12 +2743,21 @@ static void svm_complete_interrupts(struct vcpu_svm *svm) svm->vcpu.arch.nmi_injected = true; break; case SVM_EXITINTINFO_TYPE_EXEPT: - /* In case of software exception do not reinject an exception - vector, but re-execute and instruction instead */ if (is_nested(svm)) break; - if (kvm_exception_is_soft(vector)) + /* + * In case of software exceptions, do not reinject the vector, + * but re-execute the instruction instead. Rewind RIP first + * if we emulated INT3 before. + */ + if (kvm_exception_is_soft(vector)) { + if (vector == BP_VECTOR && int3_injected && + kvm_is_linear_rip(&svm->vcpu, svm->int3_rip)) + kvm_rip_write(&svm->vcpu, + kvm_rip_read(&svm->vcpu) - + int3_injected); break; + } if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) { u32 err = svm->vmcb->control.exit_int_info_err; kvm_queue_exception_e(&svm->vcpu, vector, err); |