Hello Ralf! Thank you very much for the explanations!
I wonder now that if the hypervisor now has to handle a very large page table, the timing behavior of an application in the guest cell will be negatively affected. Could this then be optimized, e.g. using "huge pages"? Is there a description for this? Thanks Jan. Ralf Ramsauer schrieb am Mittwoch, 26. Juli 2023 um 15:48:44 UTC+2: > > > On 26/07/2023 14:41, Jan-Marc Stranz wrote: > > Thanks for the tip to increase the memory area for the hypervisor! > > > > I have increased the memory area for the hypervisor from 6 MiB to 9 MiB > > and can now successfully start both guest cells with a size of 512 MiB > each. > > > > I don't know if there is a hint in the documentation for the hypervisor > > "Jailhouse" (in the GIT repository). > > If not, it would certainly be very helpful if this correlation (guest > > cell size - required memory for hypervisor) is described somewhere (e.g. > > in the file "Documentation/non-root-linux.txt"). > > Patches welcome! I'd rather recommend to print a proper error message in > the hypervisor that gives a pointer to this issue. > > Just a short explanation what happened: Jailhouse tries to map huge > pages to minimise pressure on TLB. In your case, the area isn't aligned > with huge pages, so Jailhouse must map tons of 4k-Pages to cover that > memory region. Mapping those pages requires memory for page tables, and > apparently, 6MiB weren't sufficient. > > Thanks > Ralf > > > > > Jan-Marc. > > > > Ralf Ramsauer schrieb am Mittwoch, 26. Juli 2023 um 13:12:02 UTC+2: > > > > > > > > On 26/07/2023 12:56, Jan-Marc Stranz wrote: > > > Of course, I checked the configuration for the root cell with > > "jailhouse > > > config check". > > > However, this is not changed at all while I change the > > configuration for > > > the guest cells. > > > > > > Also, everything is fine as long as I don't set the size for the > > guest > > > cell larger than 320 MiB in the guest cell configuration. > > > This only uses about 62% of the memory area reserved for the > > guest cells > > > in the configuration for the root cell. > > > > > > I will follow up on the tip to increase the memory area for the > > > hypervisor ( hypervisor_memory.size). > > > So far, 6 MiB is reserved for the hypervisor itself. > > > To what size should I increase this memory area? > > > > Just a bit more. Try 10 MiB or so. > > > > Ralf > > > > > > > > However, to find the cause in the driver or hypervisor, I lack the > > > necessary knowledge about the structure and relationships. > > > So I have to rely on external help. > > > > > > Thanks a lot! > > > Jan-Marc. > > > > > > -- > > > 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] > > > <mailto:[email protected]>. > > > To view this discussion on the web visit > > > > > > https://groups.google.com/d/msgid/jailhouse-dev/43f41f9d-0930-416b-a618-1955e237cc87n%40googlegroups.com > > < > https://groups.google.com/d/msgid/jailhouse-dev/43f41f9d-0930-416b-a618-1955e237cc87n%40googlegroups.com> > > < > https://groups.google.com/d/msgid/jailhouse-dev/43f41f9d-0930-416b-a618-1955e237cc87n%40googlegroups.com?utm_medium=email&utm_source=footer > > < > https://groups.google.com/d/msgid/jailhouse-dev/43f41f9d-0930-416b-a618-1955e237cc87n%40googlegroups.com?utm_medium=email&utm_source=footer > >>. > > > > -- > > 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] > > <mailto:[email protected]>. > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/jailhouse-dev/57a4477a-2c32-49ef-8ccc-e95e1d9fb815n%40googlegroups.com > > < > https://groups.google.com/d/msgid/jailhouse-dev/57a4477a-2c32-49ef-8ccc-e95e1d9fb815n%40googlegroups.com?utm_medium=email&utm_source=footer > >. > -- 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/10922b18-30e5-414e-8d85-7e1f33f2f9fan%40googlegroups.com.
