Hello, I am trying to figure out how the trap and callback mechanism works between a guest OS and XEN. When a guest OS starts up, it uses the HYPERVISOR_set_trap_table() to register a set of traps with XEN. For example, it registers the trap that will handle a divide_error or page_fault exception. Now when XEN gets an exception, XEN executes the do_trap() function that is found in xen/arch/x86/traps.c. do_trap() retrieves the current domain''s trap information that was registered with HYPERVISOR_set_trap_table() and fills in a structure called "guest_trap_bounce". From that point on, I don''t quite follow how the guest OS comes into play to handle the exception. Could someone please give me some directions. Thank You Richard ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel
> Hello, > > I am trying to figure out how the trap and callback mechanism works > between a guest OS and XEN. When a guest OS starts up, it uses the > HYPERVISOR_set_trap_table() to register a set of traps with XEN. > For example, it registers the trap that will handle a divide_error or > page_fault exception. > > Now when XEN gets an exception, XEN executes the do_trap() function that > is found in xen/arch/x86/traps.c. > do_trap() retrieves the current domain''s trap information that was registered > with HYPERVISOR_set_trap_table() and fills in a structure called > "guest_trap_bounce". From that point on, I don''t quite follow how the guest OS > comes into play to handle the exception. Could someone please give me some > directions.The guest_trap_counce is interpreted in arch/x86/x86_32/entry.S and used to create a stack frame on the ring-1 (guest OS) stack. -- Keir ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Xen-devel mailing list Xen-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xen-devel