[PATCH v2 0/4] x86/mm: Fix some issues with using trampoline_pgd

From: Joerg Roedel
Date: Wed Sep 29 2021 - 10:55:29 EST


From: Joerg Roedel <jroedel@xxxxxxx>

Hi,

here are a couple of fixes and documentation improvements for the
kernels use of the trampoline_pgd. The first patch adds a comment to
document that the trampoline_pgd aliases kernel page-tables in the
user address range, establishing global TLB entries for these
addresses.

The next two patches add global TLB flushes when switching to and from
the trampoline_pgd. The last patch extends the trampoline_pgd to cover
the whole kernel address range. This is needed to make sure the stack
and the real_mode_header don't get unmapped when switching to the
trampoline_pgd.

Please review.

Thanks,

Joerg

Joerg Roedel (4):
x86/realmode: Add comment for Global bit usage in trampline_pgd
x86/mm/64: Flush global TLB on AP bringup
x86/mm: Flush global TLB when switching to trampoline page-table
x86/64/mm: Map all kernel memory into trampoline_pgd

arch/x86/include/asm/realmode.h | 1 +
arch/x86/kernel/cpu/common.c | 6 ++++++
arch/x86/kernel/reboot.c | 12 ++----------
arch/x86/mm/init.c | 5 +++++
arch/x86/realmode/init.c | 31 ++++++++++++++++++++++++++++++-
5 files changed, 44 insertions(+), 11 deletions(-)


base-commit: 5816b3e6577eaa676ceb00a848f0fd65fe2adc29
--
2.33.0