On 29.10.2024 10:30, Luca Fancellu wrote: > Hi Jan, > >> On 29 Oct 2024, at 08:08, Jan Beulich <jbeul...@suse.com> 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”?
Yes. Jan
