summaryrefslogtreecommitdiff
path: root/fs/fs_context.c
diff options
context:
space:
mode:
authorJane Chu <jane.chu@oracle.com>2022-05-16 21:38:10 +0300
committerDan Williams <dan.j.williams@intel.com>2022-05-16 21:46:44 +0300
commit5898b43af954b83c4a4ee4ab85c4dbafa395822a (patch)
tree64b013402f09792225d8ac1346bc0328ceceb54d /fs/fs_context.c
parentb3fdf9398a16f01dc013967a4ab25e99c3f4fc12 (diff)
downloadlinux-5898b43af954b83c4a4ee4ab85c4dbafa395822a.tar.xz
mce: fix set_mce_nospec to always unmap the whole page
The set_memory_uc() approach doesn't work well in all cases. As Dan pointed out when "The VMM unmapped the bad page from guest physical space and passed the machine check to the guest." "The guest gets virtual #MC on an access to that page. When the guest tries to do set_memory_uc() and instructs cpa_flush() to do clean caches that results in taking another fault / exception perhaps because the VMM unmapped the page from the guest." Since the driver has special knowledge to handle NP or UC, mark the poisoned page with NP and let driver handle it when it comes down to repair. Please refer to discussions here for more details. https://lore.kernel.org/all/CAPcyv4hrXPb1tASBZUg-GgdVs0OOFKXMXLiHmktg_kFi7YBMyQ@mail.gmail.com/ Now since poisoned page is marked as not-present, in order to avoid writing to a not-present page and trigger kernel Oops, also fix pmem_do_write(). Fixes: 284ce4011ba6 ("x86/memory_failure: Introduce {set, clear}_mce_nospec()") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jane Chu <jane.chu@oracle.com> Acked-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/r/165272615484.103830.2563950688772226611.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'fs/fs_context.c')
0 files changed, 0 insertions, 0 deletions