On Mon, May 25, 2020 at 9:35 PM Lai Jiangshan <[email protected]> wrote: > > When I searched percpu data touched by entry code for #DB > protection[1], it seems to me RESTORE_CR3() does too much work, > this patchset simplifies it. > > Patch 1 enhances 21e944591102("x86/mm: Optimize RESTORE_CR3") for > kernel CR3. > > Patch 2 *reverts* 21e944591102("x86/mm: Optimize RESTORE_CR3") for > User CR3.
This series looks correct, but I don't think it's 5.8 material. I also want to try moving all this code to C, so it's possible this little series will become obsolete. > > Cc: Andy Lutomirski <[email protected]> > Cc: Peter Zijlstra (Intel) <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: [email protected] > Link: > https://lore.kernel.org/lkml/[email protected] > Lai Jiangshan (2): > x86/entry: Don't write to CR3 when restoring to kernel CR3 > x86/entry: always flush user CR3 in RESTORE_CR3 > > arch/x86/entry/calling.h | 36 ++++++++---------------------------- > arch/x86/entry/entry_64.S | 6 +++--- > 2 files changed, 11 insertions(+), 31 deletions(-) > > -- > 2.20.1 >
