When a memory error, CPU error, PCIe error, or other type of hardware error that's covered by RAS occurs, firmware should populate the shared GHES memory location with the proper GHES structures to notify the OS of the error. For example, platforms that implement firmware first handling may implement separate GHES sources for corrected errors and uncorrected errors. If the error is an uncorrectable error, then the firmware will notify the OS immediately since the error needs to be handled ASAP. The OS will then be able to take the appropriate action needed such as offlining a page. If the error is a corrected error, then the firmware will not interrupt the OS immediately. Instead, the OS will see and report the error the next time it's GHES timer expires. The kernel will first parse the GHES structures and report the errors through the kernel logs and then notify the user space through RAS trace events. This allows user space applications such as RAS Daemon to see the errors and report them however the user desires. This patchset extends the kernel functionality for RAS errors based on updates in the UEFI 2.6 and ACPI 6.1 specifications.
An example flow from firmware to user space could be: +---------------+ +-------->| | | | GHES polling |--+ +-------------+ | source | | +---------------+ +------------+ | | +---------------+ | | Kernel GHES | | | | Firmware | +-->| CPER AER and |-->| RAS trace | | | +---------------+ | | EDAC drivers | | event | +-------------+ | | | +---------------+ +------------+ | | GHES sci |--+ +-------->| source | +---------------+ Add support for Generic Hardware Error Source (GHES) v2, which introduces the capability for the OS to acknowledge the consumption of the error record generated by the Reliability, Availability and Serviceability (RAS) controller. This eliminates potential race conditions between the OS and the RAS controller. Add support for the timestamp field added to the Generic Error Data Entry v3, allowing the OS to log the time that the error is generated by the firmware, rather than the time the error is consumed. This improves the correctness of event sequences when analyzing error logs. The timestamp is added in ACPI 6.1, reference Table 18-343 Generic Error Data Entry. Add support for ARMv8 Common Platform Error Record (CPER) per UEFI 2.6 specification. ARMv8 specific processor error information is reported as part of the CPER records. This provides more detail on for processor error logs. This can help describe ARMv8 cache, tlb, and bus errors. Synchronous External Abort (SEA) represents a specific processor error condition in ARM systems. A handler is added to recognize SEA errors, and a notifier is added to parse and report the errors before the process is killed. Refer to section N.2.1.1 in the Common Platform Error Record appendix of the UEFI 2.6 specification. Currently the kernel ignores CPER records that are unrecognized. On the other hand, UEFI spec allows for non-standard (eg. vendor proprietary) error section type in CPER (Common Platform Error Record), as defined in section N2.3 of UEFI version 2.5. Therefore, user is not able to see hardware error data of non-standard section. If section Type field of Generic Error Data Entry is unrecognized, prints out the raw data in dmesg buffer, and also adds a tracepoint for reporting such hardware errors. Currently even if an error status block's severity is fatal, the kernel does not honor the severity level and panic. With the firmware first model, the platform could inform the OS about a fatal hardware error through the non-NMI GHES notification type. The OS should panic when a hardware error record is received with this severity. Add support to handle SEAs that occur while a KVM guest kernel is running. Currently these are unsupported by the guest abort handling. Depends on: [PATCH v14] acpi, apei, arm64: APEI initial support for aarch64. https://lkml.org/lkml/2016/8/10/231 V4: Add bit offset left shift to read_ack_write value Make HEST generic and generic_v2 structures a union in the ghes structure Move gdata v3 helper functions into ghes.h to avoid duplication Reorder the timestamp print and avoid memcpy Add helper functions for gdata size checking Rename the SEA functions Add helper function for GHES panics Set fru_id to NULL UUID at variable declaration Limit ARM trace event parameters to the needed structures Reorder the ARM trace event variables to save space Add comment for why we don't pass SEAs to the guest when it aborts Move ARM trace event call into GHES driver instead of CPER V3: Fix unmapped address to the read_ack_register in ghes.c Add helper function to get the proper payload based on generic data entry version Move timestamp print to avoid changing function calls in cper.c Remove patch "arm64: exception: handle instruction abort at current EL" since the el1_ia handler is already added in 4.8 Add EFI and ARM64 dependencies for HAVE_ACPI_APEI_SEA Add a new trace event for ARM type errors Add support to handle KVM guest SEAs V2: Add PSCI state print for the ARMv8 error type. Separate timestamp year into year and century using BCD format. Rebase on top of ACPICA 20160318 release and remove header file changes in include/acpi/actbl1.h. Add panic OS with fatal error status block patch. Add processing of unrecognized CPER error section patches with updates from previous comments. Original patches: https://lkml.org/lkml/2015/9/8/646 V1: https://lkml.org/lkml/2016/2/5/544 Jonathan (Zhixiong) Zhang (1): acpi: apei: panic OS with fatal error status block Tyler Baicar (9): acpi: apei: read ack upon ghes record consumption ras: acpi/apei: cper: generic error data entry v3 per ACPI 6.1 efi: parse ARMv8 processor error arm64: exception: handle Synchronous External Abort acpi: apei: handle SEA notification type for ARMv8 efi: print unrecognized CPER section ras: acpi / apei: generate trace event for unrecognized CPER section trace, ras: add ARM processor error trace event arm64: KVM: add guest SEA support arch/arm/include/asm/kvm_arm.h | 1 + arch/arm/include/asm/system_misc.h | 5 + arch/arm/kvm/mmu.c | 18 ++- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/kvm_arm.h | 1 + arch/arm64/include/asm/system_misc.h | 15 +++ arch/arm64/mm/fault.c | 71 ++++++++++-- drivers/acpi/apei/Kconfig | 14 +++ drivers/acpi/apei/ghes.c | 181 +++++++++++++++++++++++++++-- drivers/acpi/apei/hest.c | 7 +- drivers/firmware/efi/cper.c | 215 ++++++++++++++++++++++++++++++++--- drivers/ras/ras.c | 2 + include/acpi/ghes.h | 15 ++- include/linux/cper.h | 84 ++++++++++++++ include/ras/ras_event.h | 100 ++++++++++++++++ 15 files changed, 692 insertions(+), 38 deletions(-) -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. 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