• Joao Martins's avatar
    xen/acpi: upload _PSD info for non Dom0 CPUs too · 4d0f1ce6
    Joao Martins authored
    All uploaded PM data from non-dom0 CPUs takes the info from vCPU 0 and
    changing only the acpi_id. For processors which P-state coordination type
    is HW_ALL (0xFD) it is OK to upload bogus P-state dependency information
    (_PSD), because Xen will ignore any cpufreq domains created for past CPUs.
    
    Albeit for platforms which expose coordination types as SW_ANY or SW_ALL,
    this will have some unintended side effects. Effectively, it will look at
    the P-state domain existence and *if it already exists* it will skip the
    acpi-cpufreq initialization and thus inherit the policy from the first CPU
    in the cpufreq domain. This will finally lead to the original cpu not
    changing target freq to P0 other than the first in the domain. Which will
    make turbo boost not getting enabled (e.g. for 'performance' governor) for
    all cpus.
    
    This patch fixes that, by also evaluating _PSD when we enumerate all ACPI
    processors and thus always uploading the correct info to Xen. We export
    acpi_processor_get_psd() for that this purpose, but change signature
    to not assume an existent of acpi_processor given that ACPI isn't creating
    an acpi_processor for non-dom0 CPUs.
    Signed-off-by: 's avatarJoao Martins <joao.m.martins@oracle.com>
    Reviewed-by: 's avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
    Acked-by: 's avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    Signed-off-by: 's avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
    4d0f1ce6
processor.h 11 KB