On 02.07.20 12:03, Peng Fan wrote:
Hi Jan
https://events19.linuxfoundation.org/wp-content/uploads/2018/07/Consolidate-Real-Time-and-HMI-with-ACRN-Hypervisor.pdf
Have you ever see this? Page 13, there is a compare between ACRN and jailhouse
on X86.
So it show ACRN a bit better? But is there any big differences in design? I
doubt this.
You also need to read the paper where the stats came from: They
implemented APIC (GIC equivalent) pass-through also in ACRN, a feature
that Jailhouse introduced in 2013, and then tried to compare that two
Jailhouse and also RT-KVM. Unfortunately, there were configuration
mistakes in both of those other setup. The one in Jailhouse they found
themselves, redid the measurements, unsurprisingly found both to be the
same then (no hypervisor involved anymore), but they didn't update their
graphs, even not in the paper. The graphs where simply copied into that
presentation.
I attended that session and offered the presenter afterwards to review
their results in the future if those are taken over a stack they are not
familiar with. That would have also helped to avoid the architectural
mistake in their RT-KVM measurement setup which gave them result of by
one order of magnitude.
BTW, regarding direct interrupt delivery on ARM: In
https://lwn.net/Articles/820830, it is reported that Bao has "found a
way to map interrupts directly into guests". I didn't find the time yet
to check if that is actually exit-free delivery, and that as a smart
trick or rather a problematic hack. Or if that sentence is rather a
misunderstanding. There is also the sentence: "Interrupts [...] have to
be mediated through the hypervisor, which is unfortunate since that
increases latency."
Jan
--
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].
To view this discussion on the web visit
https://groups.google.com/d/msgid/jailhouse-dev/38ffb4dc-20d6-3404-cc61-ea08ea8066f1%40siemens.com.
