On 14.11.2024 10:08, Andrew Cooper wrote: > By checking that the permanent trampoline fits within 1k (at the time of > writing, it's 0x229 bytes), we can simplify the wakeup_stack handling. > > Move the setup into wakeup.S, because it's rather out of place in > trampoline.S, and change it to a local symbol. > > Drop wakeup_stack_start and WAKEUP_STACK_MIN entirely. > > No functional change. > > Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com> with one nit: > --- a/xen/arch/x86/boot/trampoline.S > +++ b/xen/arch/x86/boot/trampoline.S > @@ -156,11 +156,6 @@ GLOBAL(trampoline_xen_phys_start) > GLOBAL(trampoline_cpu_started) > .byte 0 > > -/* The first page of trampoline is permanent, the rest boot-time only. */ > -/* Reuse the boot trampoline on the 1st trampoline page as stack for wakeup. > */ > - .equ wakeup_stack, trampoline_start + PAGE_SIZE > - .global wakeup_stack > - > LABEL(trampoline_perm_end, 0) > > /* From here on early boot only. */ > diff --git a/xen/arch/x86/boot/wakeup.S b/xen/arch/x86/boot/wakeup.S > index df5ea2445739..d53f92b02463 100644 > --- a/xen/arch/x86/boot/wakeup.S > +++ b/xen/arch/x86/boot/wakeup.S > @@ -1,5 +1,10 @@ > .code16 > > +/* The first page of trampoline is permanent, the rest boot-time only. */ > +/* Reuse the boot logic on the first trampoline page as stack for wakeup. */ > + .equ wakeup_stack, trampoline_start + PAGE_SIZE > + .local wakeup_stack > + > #define wakesym(sym) (sym - wakeup_start) As you move it, it would be nice for the commentary to become a single multi-line comment rather than two single-line ones. Jan
