Even some more information: These is a function word_t Arch_setMRs_fault(tcb_t *sender, tcb_t *receiver, word_t *receiveIPCBuffer, word_t faultType) which populate a message and send it to fault handler. In this function case seL4_Fault_VCPUFault: return setMR(receiver, receiveIPCBuffer, seL4_VCPUFault_HSR, seL4_Fault_VCPUFault_get_hsr(sender->tcbFault)); This is only information that sent to fault handler, but for seL4_Fault_VMFault it provides nuch more case seL4_Fault_VMFault: { if (config_set(CONFIG_ARM_HYPERVISOR_SUPPORT)) { word_t ipa, va; va = getRestartPC(sender); ipa = (addressTranslateS1CPR(va) & ~MASK(PAGE_BITS)) | (va & MASK(PAGE_BITS)); setMR(receiver, receiveIPCBuffer, seL4_VMFault_IP, ipa); Just some addition: I have found function seL4_Fault_VCPUFault_get_HSR(seL4_Fault_t seL4_Fault) It gives me the value of HSR register, but how can I get fault address and some other (if exist) information? Thanks, ---------- Forwarded message --------- From: Leonid Meyerovich <leonid@trustedst.com> Date: Fri, Jan 26, 2024 at 11:35 AM Subject: fault processing To: <devel@sel4.systems> I am working on fault processing. When I am a fault I am calling void sel4utils_print_fault_message(seL4_MessageInfo_t tag, const char *thread_name) from sel4libsutils library I have tested it for "page fault" condition and it works fine - I am getting seL4_Fault_VMFault fault type But in certain case I have got seL4_Fault_VCPUFault type, which is not implemented sel4libsutils library I try to process this fault similar to seL4_Fault_VMFault to get all neccessary registers, but the kernel does not have functions like seL4_Fault_VCPUFault_get_IP. What is the message format for VCPU fault? Thanks