fix #28612342

commit 0db5e0223035b2c84e6186831fc27511270af812 upstream

To split up APEIs in_nmi() path, the caller needs to always be
in_nmi(). KVM shouldn't have to know about this, pull the RAS plumbing
out into a header file.

Currently guest synchronous external aborts are claimed as RAS
notifications by handle_guest_sea(), which is hidden in the arch codes
mm/fault.c. 32bit gets a dummy declaration in system_misc.h.

There is going to be more of this in the future if/when the kernel
supports the SError-based firmware-first notification mechanism and/or
kernel-first notifications for both synchronous external abort and
SError. Each of these will come with some Kconfig symbols and a
handful of header files.

Create a header file for all this.

This patch gives handle_guest_sea() a 'kvm_' prefix, and moves the
declarations to kvm_ras.h as preparation for a future patch that moves
the ACPI-specific RAS code out of mm/fault.c.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NPunit Agrawal <punit.agrawal@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NBaolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: NAlex Shi <alex.shi@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>
Reviewed-by: Nluanshi <zhangliguang@linux.alibaba.com>