Hi Jan, > On 29 Oct 2024, at 08:08, Jan Beulich <[email protected]> wrote: > > On 28.10.2024 18:38, Ayan Kumar Halder wrote: >> On 28/10/2024 15:01, Jan Beulich wrote: >>> On 28.10.2024 15:39, Ayan Kumar Halder wrote: >>>> On 28/10/2024 12:55, Jan Beulich wrote: >>>>> On 28.10.2024 13:45, Ayan Kumar Halder wrote: >>>>>> --- a/xen/arch/Kconfig >>>>>> +++ b/xen/arch/Kconfig >>>>>> @@ -6,11 +6,13 @@ config PHYS_ADDR_T_32 >>>>>> >>>>>> config NR_CPUS >>>>>> int "Maximum number of CPUs" >>>>>> + range 1 1 if ARM && MPU >>>>>> range 1 16383 >>>>>> default "256" if X86 >>>>>> default "8" if ARM && RCAR3 >>>>>> default "4" if ARM && QEMU >>>>>> default "4" if ARM && MPSOC >>>>>> + default "1" if ARM && MPU >>>>>> default "128" if ARM >>>>>> help >>>>>> Controls the build-time size of various arrays and bitmaps >>>>> I'm afraid I can't easily tell whether MPU can be used together with any >>>>> of >>>>> RCAR3, QEMU, or MPSOC. If it can, the new default line would need to move >>>>> up, as it's the first one that has a match on its condition which is being >>>>> used. >>>> MPU cannot be used with any of the existing platforms. >>> That is - qemu can't emulate such an environment, i.e. even QEMU and MPU >>> don't go together? >> >> Qemu has support for Aarch32 MPU at EL2 and EL1 (ie R52). As far as I am >> aware, there is no support for Aarch64 MPU in Qemu (ie R82). >> >> Even for R52, I could not get the upstream Qemu working (emulating some >> Arm reference platform). >> >> I could get the Xilinx fork of Qemu (https://github.com/Xilinx/qemu) >> working which emulates AMD's SoC using R52. >> >> However, this should not impact the current patch. There is no Qemu in >> xen/arch/arm/platforms/*. > > Aiui that's not relevant. There is a QEMU item in > xen/arch/arm/platforms/Kconfig. > I continue to fail to see why that couldn't be selected together with MPU. > Yet if > it can be, you'd end up with a default of 4, not 1, if it actually _is_ > selected. > Alternatively QEMU (and maybe also RCAR3 and MPSOC) need to be mutually > exclusive > with MPU. Hmm, looks like that's already the case, by patch 2 suppressing the > "Platform Support" prompt. While that looks fragile to me, I'm sorry for the > noise then.
Are you suggesting to move "default "1" if ARM && MPU” right after “default "256" if X86”? Cheers, Luca
