On 27/06/19 12:39, Nadav Amit wrote: > Do not assume that the local APIC is in a xAPIC mode after reset. > Instead reset it first, since it might be in x2APIC mode, from which a > transition in xAPIC is invalid. > > To use reset_apic(), change it to use xapic_write(), in order to make safe to use > while apic_ops might change concurrently by x2apic_enable(). > > Cc: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx> > Signed-off-by: Nadav Amit <nadav.amit@xxxxxxxxx> > --- Also needs the 32-bit version: diff --git a/x86/cstart.S b/x86/cstart.S index 2fa4c30..575101b 100644 --- a/x86/cstart.S +++ b/x86/cstart.S @@ -143,6 +143,7 @@ ap_start32: lock/xaddl %esp, smp_stacktop setup_percpu_area call prepare_32 + call reset_apic call save_id call load_tss call enable_apic @@ -155,6 +156,7 @@ ap_start32: jmp 1b start32: + call reset_apic call save_id call load_tss call mask_pic_interrupts Paolo
