linux/arch/arm64/include/asm/kvm_ras.h
James Morse d44f1b8dd7 arm64: KVM/mm: Move SEA handling behind a single 'claim' interface
To split up APEIs in_nmi() path, the caller needs to always be
in_nmi(). Add a helper to do the work and claim the notification.

When KVM or the arch code takes an exception that might be a RAS
notification, it asks the APEI firmware-first code whether it wants
to claim the exception. A future kernel-first mechanism may be queried
afterwards, and claim the notification, otherwise we fall through
to the existing default behaviour.

The NOTIFY_SEA code was merged before considering multiple, possibly
interacting, NMI-like notifications and the need to consider kernel
first in the future. Make the 'claiming' behaviour explicit.

Restructuring the APEI code to allow multiple NMI-like notifications
means any notification that might interrupt interrupts-masked
code must always be wrapped in nmi_enter()/nmi_exit(). This will
allow APEI to use in_nmi() to use the right fixmap entries.

Mask SError over this window to prevent an asynchronous RAS error
arriving and tripping 'nmi_enter()'s BUG_ON(in_nmi()).

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-02-07 23:10:45 +01:00

26 lines
603 B
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2018 - Arm Ltd */
#ifndef __ARM64_KVM_RAS_H__
#define __ARM64_KVM_RAS_H__
#include <linux/acpi.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <asm/acpi.h>
/*
* Was this synchronous external abort a RAS notification?
* Returns '0' for errors handled by some RAS subsystem, or -ENOENT.
*/
static inline int kvm_handle_guest_sea(phys_addr_t addr, unsigned int esr)
{
/* apei_claim_sea(NULL) expects to mask interrupts itself */
lockdep_assert_irqs_enabled();
return apei_claim_sea(NULL);
}
#endif /* __ARM64_KVM_RAS_H__ */