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linux/arch/arm64/include/asm/kvm_ras.h

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KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing 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: James Morse <james.morse@arm.com> Reviewed-by: Punit Agrawal <punit.agrawal@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>
2019-01-29 18:48:49 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2018 - Arm Ltd */
#ifndef __ARM64_KVM_RAS_H__
#define __ARM64_KVM_RAS_H__
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>
2019-01-29 18:48:50 +00:00
#include <linux/acpi.h>
#include <linux/errno.h>
KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing 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: James Morse <james.morse@arm.com> Reviewed-by: Punit Agrawal <punit.agrawal@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>
2019-01-29 18:48:49 +00:00
#include <linux/types.h>
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>
2019-01-29 18:48:50 +00:00
#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);
}
KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing 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: James Morse <james.morse@arm.com> Reviewed-by: Punit Agrawal <punit.agrawal@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>
2019-01-29 18:48:49 +00:00
#endif /* __ARM64_KVM_RAS_H__ */
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