On Fri, Feb 8, 2019 at 3:13 PM James Morse <james.morse@xxxxxxx> wrote: > > Hi Rafael, > > On 08/02/2019 11:40, Rafael J. Wysocki wrote: > > On Tuesday, January 29, 2019 7:48:36 PM CET James Morse wrote: > >> This series aims to wire-up arm64's fancy new software-NMI notifications > >> for firmware-first RAS. These need to use the estatus-queue, which is > >> also needed for notifications via emulated-SError. All of these > >> things take the 'in_nmi()' path through ghes_copy_tofrom_phys(), and > >> so will deadlock if they can interact, which they might. > > >> Known issues: > >> * ghes_copy_tofrom_phys() already takes a lock in NMI context, this > >> series moves that around, and makes sure we never try to take the > >> same lock from different NMIlike notifications. Since the switch to > >> queued spinlocks it looks like the kernel can only be 4 context's > >> deep in spinlock, which arm64 could exceed as it doesn't have a > >> single architected NMI. This would be fixed by dropping back to > >> test-and-set when the nesting gets too deep: > >> lore.kernel.org/r/1548215351-18896-1-git-send-email-longman@xxxxxxxxxx > >> > >> * Taking an NMI from a KVM guest on arm64 with VHE leaves HCR_EL2.TGE > >> clear, meaning AT and TLBI point at the guest, and PAN/UAO are squiffy. > >> Only TLBI matters for APEI, and this is fixed by Julien's patch: > >> http://lore.kernel.org/r/1548084825-8803-2-git-send-email-julien.thierry@xxxxxxx > >> > >> * Linux ignores the physical address mask, meaning it doesn't call > >> memory_failure() on all the affected pages if firmware or hypervisor > >> believe in a different page size. Easy to hit on arm64, (easy to fix too, > >> it just conflicts with this series) > > > >> James Morse (26): > >> ACPI / APEI: Don't wait to serialise with oops messages when > >> panic()ing > >> ACPI / APEI: Remove silent flag from ghes_read_estatus() > >> ACPI / APEI: Switch estatus pool to use vmalloc memory > >> ACPI / APEI: Make hest.c manage the estatus memory pool > >> ACPI / APEI: Make estatus pool allocation a static size > >> ACPI / APEI: Don't store CPER records physical address in struct ghes > >> ACPI / APEI: Remove spurious GHES_TO_CLEAR check > >> ACPI / APEI: Don't update struct ghes' flags in read/clear estatus > >> ACPI / APEI: Generalise the estatus queue's notify code > >> ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors > >> ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI > >> ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue > >> KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing > >> arm64: KVM/mm: Move SEA handling behind a single 'claim' interface > >> ACPI / APEI: Move locking to the notification helper > >> ACPI / APEI: Let the notification helper specify the fixmap slot > >> ACPI / APEI: Pass ghes and estatus separately to avoid a later copy > >> ACPI / APEI: Make GHES estatus header validation more user friendly > >> ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER > >> length > >> ACPI / APEI: Only use queued estatus entry during > >> in_nmi_queue_one_entry() > >> ACPI / APEI: Use separate fixmap pages for arm64 NMI-like > >> notifications > >> mm/memory-failure: Add memory_failure_queue_kick() > >> ACPI / APEI: Kick the memory_failure() queue for synchronous errors > >> arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work > >> firmware: arm_sdei: Add ACPI GHES registration helper > >> ACPI / APEI: Add support for the SDEI GHES Notification type > > > > I can apply patches in this series up to and including patch [21/26]. > > > > Do you want me to do that? > > 9-12, 17-19, 21 are missing any review/ack tags, so I wouldn't ask, but as > you're offering, yes please! > > > > Patch [22/26] requires an ACK from mm people. > > > > Patch [23/26] has a problem that randconfig can generate a configuration > > in which memory_failure_queue_kick() is not present, so it is necessary > > to add a CONFIG_MEMORY_FAILURE dependency somewhere for things to > > work (or define an empty stub for that function in case the symbol is > > not set). > > Damn-it! Thanks, I was just trying to work that report out... > > > > If patches [24-26/26] don't depend on the previous two, I can try to > > apply them either, so please let me know. > > 22-24 depend on each other. Merging 24 without the other two is no-improvement, > so I'd like them to be kept together. > > 25-26 don't depend on 22-24, but came later so that they weren't affected by the > same race. > (note to self: describe that in the cover letter next time.) > > > If I apply the tag's and Boris' changes and post a tested v9 as 1-21, 25-26, is > that easier, or does it cause extra work? Actually, I went ahead and applied them, since I had the 1-21 ready anyway. I applied the Boris' fixups manually which led to a bit of rebasing, so please check my linux-next branch. Thanks!
