On 24/06/15 10:25, Razvan Cojocaru wrote: > On 06/24/2015 12:14 PM, Fanhenglong wrote: >> I want to debug the procedure of windows os install with windbg, >> >> windbg executes instruction(fxsave) after the blank vm is started and >> before guest iso start to install, >> >> fxsave trigger the following code path: >> vmx_vmexit_handler(EXIT_REASON_EPT_VIOLATION) >> ->ept_handle_violation >> ->hvm_hap_nested_page_fault >> ->handle_mmio_with_translation >> ->handle_mmio >> ->hvm_emulate_one >> ->x86_emulate >> >> *X86_emulate return X86EMUL_UNHANDLEABLE* > How are you using Xen in this case? Are you by any chance using the > vm_event system in a way that sends back an "emulate" vm_event response > from userspace? > > You might want to look at x86_emulate() in > xen/arch/x86/x86_emulate/x86_emulate.c and see if (and how) fxsave is > being handled.
The fxsave instruction has no emulation implementation. "0f ae 07" is "fxsave (%rdi)" which means that either introspection is active, or %rdi is a pointer into an MMIO region. ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
