• Vitaly Kuznetsov's avatar
    xen: introduce xen_vcpu_id mapping · 88e957d6
    Vitaly Kuznetsov authored
    It may happen that Xen's and Linux's ideas of vCPU id diverge. In
    particular, when we crash on a secondary vCPU we may want to do kdump
    and unlike plain kexec where we do migrate_to_reboot_cpu() we try
    booting on the vCPU which crashed. This doesn't work very well for
    PVHVM guests as we have a number of hypercalls where we pass vCPU id
    as a parameter. These hypercalls either fail or do something
    unexpected.
    
    To solve the issue introduce percpu xen_vcpu_id mapping. ARM and PV
    guests get direct mapping for now. Boot CPU for PVHVM guest gets its
    id from CPUID. With secondary CPUs it is a bit more
    trickier. Currently, we initialize IPI vectors before these CPUs boot
    so we can't use CPUID. Use ACPI ids from MADT instead.
    Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
    Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
    88e957d6
xen-ops.h 4.72 KB