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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 0C650160009 X-Stat-Signature: o99i5t1kpwpuh7c99sd645ktwr4d4e1s X-Rspam-User: X-HE-Tag: 1701366000-575353 X-HE-Meta: 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 V+GUSf9f VjqzhIAVxBqxjc5U5eyRnmSjhByT/gZj/Y1jsDVpSAUpxV2t7GFSa7WB/KbSJDs6gChmQfxawDKE0cmnAdildufQd5fv/y3QJ6wmFwHeYUbWXvUo81PHt5Bfpr3KBuI8GyI+ntqoBaL+/W2NADCG4H3EBSvelKnbPPYtY7Wukup3XrjGLDk08koUDV0oZ/7To0a2nuf4u5kkM3wfPQLIK5WVIgQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi Shuai, On 07/10/2023 08:28, Shuai Xue wrote: > There are two major types of uncorrected recoverable (UCR) errors : Is UCR a well known x86 acronym? It's best to just spell this out each time, there is enough jargon in this area already. > > - Action Required (AR): The error is detected and the processor already > consumes the memory. OS requires to take action (for example, offline > failure page/kill failure thread) to recover this uncorrectable error. > > - Action Optional (AO): The error is detected out of processor execution > context. Some data in the memory are corrupted. But the data have not > been consumed. OS is optional to take action to recover this > uncorrectable error. As elsewhere, please don't think of errors as 'action required', this is how things get reported to user-space. Action-required for one thread may be action-optional for another that has the same page mapped - its really not a property of the error. It would be better to describe this as synchronous and asynchronous, or in-band and out-of-band. > The essential difference between AR and AO errors is that AR is a > synchronous event, while AO is an asynchronous event. The hardware will > signal a synchronous exception (Machine Check Exception on X86 and > Synchronous External Abort on Arm64) when an error is detected and the > memory access has been architecturally executed. > When APEI firmware first is enabled, a platform may describe one error > source for the handling of synchronous errors (e.g. MCE or SEA notification > ), or for handling asynchronous errors (e.g. SCI or External Interrupt > notification). In other words, we can distinguish synchronous errors by > APEI notification. For AR errors, kernel will kill current process > accessing the poisoned page by sending SIGBUS with BUS_MCEERR_AR. In > addition, for AO errors, kernel will notify the process who owns the > poisoned page by sending SIGBUS with BUS_MCEERR_AO in early kill mode. > However, the GHES driver always sets mf_flags to 0 so that all UCR errors > are handled as AO errors in memory failure. To make this easier to read: UCR and AR -> synchronous AO -> asynchronous > To this end, set memory failure flags as MF_ACTION_REQUIRED on synchronous > events. > Fixes: ba61ca4aab47 ("ACPI, APEI, GHES: Add hardware memory error recovery support")' Erm, this predates arm64 support, and what you have here doesn't change the behaviour on x86. You can blame 7f17b4a121d0d50 ("ACPI: APEI: Kick the memory_failure() queue for synchronous errors"), which should have covered this. > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c > index ef59d6ea16da..88178aa6222d 100644 > --- a/drivers/acpi/apei/ghes.c > +++ b/drivers/acpi/apei/ghes.c > @@ -101,6 +101,20 @@ static inline bool is_hest_type_generic_v2(struct ghes *ghes) > return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2; > } > > +/* > + * A platform may describe one error source for the handling of synchronous > + * errors (e.g. MCE or SEA), or for handling asynchronous errors (e.g. SCI > + * or External Interrupt). On x86, the HEST notifications are always > + * asynchronous, so only SEA on ARM is delivered as a synchronous > + * notification. > + */ > +static inline bool is_hest_sync_notify(struct ghes *ghes) > +{ > + u8 notify_type = ghes->generic->notify.type; > + > + return notify_type == ACPI_HEST_NOTIFY_SEA; > +} and as you had in earlier versions, sometimes SDEI. SDEI can report by synchronous and asynchronous errors, I wouldn't too surprised if the hardware NMI can be used for the same. It would be good to chase up having a hint of this in the CPER records and pass that in here as a hint. Unfortunately, its not safe to assume either way for SDEI. Reviewed-by: James Morse Thanks, James