* Jan Kiszka <[email protected]> [2017-07-26 07:38:41 +0200]: [...]
> >> Valentine > > > > That's interesting. So we kidnap one of those timers to the hypervisor only > > (since the cells are using APIC timers and are good with them) and gain > > timers on that level, right? Leaving the root cell out of the way on the > > watchdog task looks safer for me as well (reading through the thread). We > > could have policies to reload cells even without participation of the root > > one. Has anyone experimented with those different clocks on x86 already? > > > > In this last comments, I was not talking about a timer but a clock. We > already share the PM "Timer" (which is a clock in reality) across all > cells (because it is read-only and trivially handed out via PIO access > masks). We could also use it in the hypervisor on x86 in order to gain a Do you say it is read-only because we only see an inl() call on that address at timing.c or because any write would be Jailhouse-blocked (I could not find any code doing said block, but maybe I missed it)? I also ask that targeting another thing: would it be trivial, as the code is, to enable the RTC region on both root and inmate cell, so that an inmate Linux is given a permanent clock as well? I'm doing the test now, but just in case... > notion of time. However, we may also need a timer in order to implement > a watchdog. And, with safety in mind, we may need some redundancy in > that concept, e.g. a second independent time source, to avoid nasty > error modes when some time source goes mad. > > Regarding cell management without the root cell: If it's only about > restart, that would be doable. But generally, this is not possibly > without reload. And loading can only be done with the help of the root > cell. That's an architectural property of Jailhouse, to offload all the > logic and drivers and you-name-it to the root cell. So if if cell-reloading without the root cell is a no-go, we're back better off generating the watchdog ticks from the root cell (and not the hypervisor), no? > > Jan -- Gustavo Lima Chaves Intel - Open Source Technology Center -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
