RE: [RFC PATCH 0/5] hw/arm/virt: Add support for user-creatable nested SMMUv3

[Shameerali Kolothum Thodi via <qemu-arm@nongnu.org>]

Hi Nathan,

> -----Original Message-----
> From: Nathan Chen <nathanc@nvidia.com>
> Sent: Friday, December 13, 2024 1:02 AM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: qemu-arm@nongnu.org; qemu-devel@nongnu.org;
> eric.auger@redhat.com; peter.maydell@linaro.org; jgg@nvidia.com;
> ddutile@redhat.com; Linuxarm <linuxarm@huawei.com>; Wangzhou (B)
> <wangzhou1@hisilicon.com>; jiangkunkun <jiangkunkun@huawei.com>;
> Jonathan Cameron <jonathan.cameron@huawei.com>;
> zhangfei.gao@linaro.org; Nicolin Chen <nicolinc@nvidia.com>
> Subject: Re: [RFC PATCH 0/5] hw/arm/virt: Add support for user-creatable
> nested SMMUv3
> 
> 
>  >with an error message indicating DMA mapping failed for the
> passthrough >devices.
> 
> A correction - the message indicates UEFI failed to find a mapping for
> the boot partition ("map: no mapping found"), not that DMA mapping
> failed. But earlier EDK debug logs still show PCI host bridge resource
> conflicts for the passthrough devices that seem related to the VM boot
> failure.

I have tried a 2023 version EFI which works. And for more recent tests I am
using a one built directly from,
https://github.com/tianocore/edk2.git master

Commit: 0f3867fa6ef0("UefiPayloadPkg/UefiPayloadEntry: Fix PT protection
in 5 level paging"

With both, I don’t remember seeing any boot failure and the above UEFI
related "map: no mapping found" error. But the Guest kernel at times
complaints about pci bridge window memory assignment failures.
...
pci 0000:10:01.0: bridge window [mem size 0x00200000 64bit pref]: can't assign; no space
pci 0000:10:01.0: bridge window [mem size 0x00200000 64bit pref]: failed to assign
pci 0000:10:00.0: bridge window [io  size 0x1000]:can't assign; no space
...

But Guest still boots and worked fine so far.

Thanks,
Shameer