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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [XEN PATCH v1] xen/arm : Add support for SMMUv3 driver
Hello Oleksandr, > On 6 Nov 2020, at 1:00 pm, Oleksandr Andrushchenko > <Oleksandr_Andrushchenko@xxxxxxxx> wrote: > > Hello, Rahul! > > On 11/6/20 2:48 PM, Rahul Singh wrote: >> Hello Oleksandr, >> >>> On 2 Nov 2020, at 10:12 am, Oleksandr Andrushchenko >>> <Oleksandr_Andrushchenko@xxxxxxxx> wrote: >>> >>> Hi, >>> >>> On 11/2/20 11:55 AM, Bertrand Marquis wrote: >>>> Hi, >>>> >>>>> On 2 Nov 2020, at 05:55, Oleksandr Andrushchenko <andr2000@xxxxxxxxx> >>>>> wrote: >>>>> >>>>> Hi, Julien! >>>>> >>>>> On 10/30/20 7:18 PM, Julien Grall wrote: >>>>>> Hi Oleksandr, >>>>>> >>>>>> On 30/10/2020 10:44, Oleksandr Andrushchenko wrote: >>>>>>> On 10/20/20 6:25 PM, Rahul Singh wrote: >>>>>>>> Add support for ARM architected SMMUv3 implementations. It is based on >>>>>>>> the Linux SMMUv3 driver. >>>>>>>> >>>>>>>> Major differences between the Linux driver are as follows: >>>>>>>> 1. Only Stage-2 translation is supported as compared to the Linux >>>>>>>> driver >>>>>>>> that supports both Stage-1 and Stage-2 translations. >>>>>>> First of all thank you for the efforts! >>>>>>> >>>>>>> I tried the patch with QEMU and would like to know if my understanding >>>>>>> correct >>>>>>> >>>>>>> that this combination will not work as of now: >>>>>>> >>>>>>> (XEN) SMMUv3: /smmuv3@9050000: SMMUv3: DT value = eventq >>>>>>> (XEN) Data Abort Trap. Syndrome=0x1940010 >>>>>>> (XEN) Walking Hypervisor VA 0x40031000 on CPU0 via TTBR >>>>>>> 0x00000000b8469000 >>>>>>> (XEN) 0TH[0x0] = 0x00000000b8468f7f >>>>>>> >>>>>>> [snip] >>>>>>> >>>>>>> If this is expected then is there any plan to make QEMU work as well? >>>>>>> >>>>>>> I see [1] says that "Only stage 1 and AArch64 PTW are supported." on >>>>>>> QEMU side. >>>>>> Just for clarication, you are trying to boot Xen on QEMU, right? >>>>> Exactly >>>>>> You might be able to use the stage-1 page-tables to isolate each device >>>>>> in Xen. However, I don't think you will be able to share the P2M because >>>>>> the page-tables layout between stage-1 and stage-2 is different. >>>>> So, it is even more work then >>>> Overall it would make more sense to spend some time adding proper support >>>> in Qemu then trying to modify the driver to support Qemu right now. >>>> >>>>>>> We are interested in QEMU/SMMUv3 as a flexible platform for PCI >>>>>>> passthrough >>>>>>> >>>>>>> implementation, so it could allow testing different setups and >>>>>>> configurations with QEMU. >>>>>> I would recommend to get the SMMU supporting supporting stage-2 >>>>>> page-tables. >>>>> You mean in QEMU? >>>> See before. >>>> >>>>>> Regardless that, I think Xen should be able to say the SMMU is not >>>>>> supported rather than crashing. >>>>> Yes, that would be nice >>>> Fully agree and we will look into that. >>>> >>>> Anything you could share so that we could quickly reproduce your setup >>>> would be more then great. >>> Nothing special, >>> >>> qemu/aarch64-softmmu/qemu-system-aarch64 -machine type=virt -machine >>> virt,gic-version=2 \ >>> >>> -machine virtualization=true -cpu cortex-a57 -smp 4 -m 2048 -nic >>> user,hostfwd=tcp:127.0.0.1:2222-:22 \ >>> >>> -nographic -serial mon:stdio [..snip..] >>> >>> I also set iommu to smmuv3 in my tests, QEMU emulator version 4.2.1 >> I just checked and confirmed that QEMU is booting with XEN SMMUv3 patch and >> XEN is able to say SMMU translation is not supported. As XEN supports >> Stage-2 translation and QEMU supports Stage-1 only. >> >> >> (XEN) SMMUv3: /smmuv3@9050000: SMMUv3: DT value = eventq >> (XEN) SMMUv3: /smmuv3@9050000: IDR0.COHACC overridden by FW configuration >> (false) >> (XEN) SMMUv3: /smmuv3@9050000: no translation support! >> (XEN) I/O virtualisation disabled >> >> Only difference I observed is that you have to add option "-machine >> virt,iommu=smmuv3 “ when launching the QEMU. > I do use the option I used "-machine virt,iommu=smmuv3 “ option while creating the virt-dtb and while launching the QEMU. I also observed the same error what you observed if I am not using the "-machine virt,iommu=smmuv3 “ options when launching the QEMU so I thought this might be case for you also but anyways you have use the options it might be other issue. >> >> Please let me know if it also works for you. > > Well, I should have reported that earlier that I do not use the staging Xen > at the moment, > > it is 4.14.0. So, can this be a problem with that Xen version? I don’t think so this is the problem with the XEN version. > > Anyways, if it works with the staging then everything looks ok > > Thank you, > > Oleksandr > >> >>>> Regards >>>> Bertrand >>>> >>>>>> Cheers, >>>>>> >>>>> Thank you, >>>>> >>>>> Oleksandr Regards, Rahul
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