On 26/07/17 15:48, Andy Lutomirski wrote: > On Mon, Jul 24, 2017 at 7:28 AM, Juergen Gross <jgr...@suse.com> wrote: >> When running as Xen pv-guest the exception frame on the stack contains >> %r11 and %rcx additional to the other data pushed by the processor. >> >> Instead of having a paravirt op being called for each exception type >> prepend the Xen specific code to each exception entry. When running as >> Xen pv-guest just use the exception entry with prepended instructions, >> otherwise use the entry without the Xen specific code. > > I think this is a nice cleanup, but I'm wondering if it would be even > nicer if the Xen part was kept out-of-line. That is, could Xen have > little stubs like: > > xen_alignment_check: > pop %rcx > pop %r11 > jmp alignment_check > > rather than using the macros in entry_64.S that you have? Then you > could adjust set_trap_gate instead of pack_gate and maybe even do > something like: > > #define set_trap_gate(..., name, ...) set_native_or_xen_trap_gate(..., > name, xen_##name, ...)
I think I'll have something like: #define pv_trap_entry(name) (xen_pv_domain() ? xen_ ## name : name) and use it like: set_intr_gate(X86_TRAP_AC, pv_trap_entry(alignment_check)); This will avoid having to define macros for all variants of set_intr_gate(), e.g. set_intr_gate_ist(), set_system_intr_gate(). Do you have any objections? Juergen _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel