On 10/07/14 11:02, Marek Vasut wrote: > On Thursday, July 10, 2014 at 01:05:39 AM, Dmitry Kasatkin wrote: >> On 10 July 2014 00:00, Marek Vasut <marex@xxxxxxx> wrote: >>> On Tuesday, July 08, 2014 at 10:07:16 AM, Dmitry Kasatkin wrote: >>> [...] >>> >>>>> Right, but my concern is not about unloading the kernel module, but >>>>> about the IMA module parameters left initialized. The existing code >>>>> will continue using ahash (software version), even though the kernel >>>>> module was unloaded, not shash. My question is about the software >>>>> implementations of ahash vs. shash performance. >>>>> >>>>> Mimi >>>> If HW driver will not be available, ahash loads generic driver which is >>>> using shash. >>>> Performance of that will be the same as for using shash directly. >>> Hi Dmitry, I think Mimi is concerned about the crypto accelerator dying >>> mid- flight. >>> >>> Imagine a situation where you have a hardware crypto accelerator >>> connected via USB. You happily use IMA with this setup for days and then >>> someone comes around and pulls the USB cable out. Will this be able to >>> cope with such situation, for example by switching to software >>> operations or such in some sane way ? >>> >>> I presume that's the concern here. >>> >>> Best regards, >>> Marek Vasut >> Hi Marek, > Hi! > >> Nice to here from you. How was your rest stay at Japan? > Thanks for asking, not sure there is a super-positive ultra-awesome word to > express that, so in short, I had the time of my life. Love that country ;-) > >> I have not seen any expression of such concern. > All right, that was my understanding of the entire discussion -- an accelerator > dying mid-way and what will IMA do about that. > >> But as we fallback to early allocated shash, which is not USB yet, >> then there is no problem. >> ahash itself does not bring any other additional problem than shash itself. >> They are compiled builtin together. > Sure, I understood that. But what will happen if the ahash accelerator stops > working mid-flight, will IMA also go bonkers or is there some graceful stop? shash fallback will be used. > Best regards, > Marek Vasut > -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
