• Xiaochen Shen's avatar
    x86/resctrl: Check monitoring static key in the MBM overflow handler · 536a0d8e
    Xiaochen Shen authored
    Currently, there are three static keys in the resctrl file system:
    rdt_mon_enable_key and rdt_alloc_enable_key indicate if the monitoring
    feature and the allocation feature are enabled, respectively. The
    rdt_enable_key is enabled when either the monitoring feature or the
    allocation feature is enabled.
    
    If no monitoring feature is present (either hardware doesn't support a
    monitoring feature or the feature is disabled by the kernel command line
    option "rdt="), rdt_enable_key is still enabled but rdt_mon_enable_key
    is disabled.
    
    MBM is a monitoring feature. The MBM overflow handler intends to
    check if the monitoring feature is not enabled for fast return.
    
    So check the rdt_mon_enable_key in it instead of the rdt_enable_key as
    former is the more accurate check.
    
     [ bp: Massage commit message. ]
    
    Fixes: e3302683 ("x86/intel_rdt/mbm: Handle counter overflow")
    Signed-off-by: default avatarXiaochen Shen <xiaochen.shen@intel.com>
    Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
    Link: https://lkml.kernel.org/r/1576094705-13660-1-git-send-email-xiaochen.shen@intel.com
    536a0d8e
monitor.c 15.9 KB