• zhenwei pi's avatar
    mm/memory-failure.c: move clear_hwpoisoned_pages · 60f272f6
    zhenwei pi authored
    Patch series "memory-failure: fix hwpoison_filter", v2.
    
    As well known, the memory failure mechanism handles memory corrupted
    event, and try to send SIGBUS to the user process which uses this
    corrupted page.
    
    For the virtualization case, QEMU catches SIGBUS and tries to inject MCE
    into the guest, and the guest handles memory failure again.  Thus the
    guest gets the minimal effect from hardware memory corruption.
    
    The further step I'm working on:
    
    1, try to modify code to decrease poisoned pages in a single place
       (mm/memofy-failure.c: simplify num_poisoned_pages_dec in this series).
    
    2, try to use page_handle_poison() to handle SetPageHWPoison() and
       num_poisoned_pages_inc() together.  It would be best to call
       num_poisoned_pages_inc() in a single place too.
    
    3, introduce memory failure notifier list in memory-failure.c: notify
       the corrupted PFN to someone who registers this list.  If I can
       complete [1] and [2] part, [3] will be quite easy(just call notifier
       list after increasing poisoned page).
    
    4, introduce memory recover VQ for memory balloon device, and registers
       memory failure notifier list.  During the guest kernel handles memory
       failure, balloon device gets notified by memory failure notifier list,
       and tells the host to recover the corrupted PFN(GPA) by the new VQ.
    
    5, host side remaps the corrupted page(HVA), and tells the guest side
       to unpoison the PFN(GPA).  Then the guest fixes the corrupted page(GPA)
       dynamically.
    
    
    This patch (of 5):
    
    clear_hwpoisoned_pages() clears HWPoison flag and decreases the number of
    poisoned pages, this actually works as part of memory failure.
    
    Move this function from sparse.c to memory-failure.c, finally there is no
    CONFIG_MEMORY_FAILURE in sparse.c.
    
    Link: https://lkml.kernel.org/r/20220509105641.491313-1-pizhenwei@bytedance.com
    Link: https://lkml.kernel.org/r/20220509105641.491313-2-pizhenwei@bytedance.comSigned-off-by: default avatarzhenwei pi <pizhenwei@bytedance.com>
    Acked-by: default avatarNaoya Horiguchi <naoya.horiguchi@nec.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    60f272f6
sparse.c 25.7 KB