Hi Harb, On 2016/10/20 0:59, Abdulhamid, Harb wrote: > On 10/18/2016 8:44 AM, Hanjun Guo wrote: >> Hi Tyler, >> >> On 2016/10/8 5:31, Tyler Baicar wrote: >>> ARM APEI extension proposal added SEA (Synchrounous External >>> Abort) notification type for ARMv8. >>> Add a new GHES error source handling function for SEA. If an error >>> source's notification type is SEA, then this function can be registered >>> into the SEA exception handler. That way GHES will parse and report >>> SEA exceptions when they occur. >> Does this SEA is replayed by the firmware (firmware first handling) >> or directly triggered by the hardware when error is happened? > Architecturally, an SEA must be synchronous and *precise*, so if you > take an SEA on a particular load instruction, firmware/hardware should > not be corrupting the context/state of the PE to allow software to > determine which thread/process encountered the abort. GHES error status That's my concern too, and that's why I raised my question :) > block will be expose to software with information about the type, > severity, physical address impacted. > > Generally the error status block is populated by firmware. However, as > long as the above requirement is met, I don't think the spec precludes > error status block being populated by hardware. Those details must be > completely transparent to software. > > Finally, to answer your more specific question: If the implementation > of firmware-first involves trapping the SEA in EL3 to do some firmware > first handling, firmware must maintain the context of the offending ELx, > generate an error record, and then "replay" the exception to normal > (non-secure) software at the appropriate vector base address. > Thank you for your answer, it clears my confusion now, I will try something similar on ARM64 platform, will get back to you if I get blocks. Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
