Re: [PATCH v4 00/11] virtio-iommu: Add ACPI support

[Haiwei Li <lihaiwei.kernel@gmail.com>]

On Fri, Oct 8, 2021 at 11:18 PM Jean-Philippe Brucker
<jean-philippe@linaro.org> wrote:
>
> On Tue, Oct 05, 2021 at 11:45:42AM -0400, Michael S. Tsirkin wrote:
> > Looks like this can not be applied yet because the bypass bit
> > isn't in yet. what's up with that?
>
> The boot-bypass bit isn't a hard dependency for this series, but it will
> be needed for full support eventually. It will be delayed by spec and
> Linux header changes
>
> In the meantime we can work around the problem by having the boot disks
> bypass the IOMMU (virtio without iommu-platform, or iommu-bypass bus).

Hi Jean,

I have tested on x86 platform with environment:

qemu, your personal repo: http://jpbrucker.net/git/qemu, branch:
virtio-iommu/acpi-2021-10-01
linux kernel, 5.14
qemu command, with '-device virtio-iommu' and boot disk
'virtio-blk-pci,iommu_platform=off'

But the guest boot failed. The print is as follows:

Begin: Loading essential drivers ... done.
Begin: Running /scripts/init-premount ... done.
Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done.
Begin: Running /scripts/local-premount ... [    7.490238] Btrfs
loaded, crc32c=crc32c-generic, zoned=no
Scanning for Btrfs filesystems
done.
[   10.593238] _warn_unseeded_randomness: 300 callbacks suppressed
[   10.593243] random: get_random_u32 called from
bucket_table_alloc.isra.0+0x123/0x430 with crng_init=0
[   37.534015] random: get_random_u64 called from
dup_task_struct+0x415/0xa10 with crng_init=0
[   37.539950] random: get_random_u64 called from
arch_pick_mmap_layout+0x411/0x5e0 with crng_init=0
[   37.539973] random: get_random_u64 called from
arch_pick_mmap_layout+0x381/0x5e0 with crng_init=0
Begin: Waiting for root file system ... [   38.624374]
_warn_unseeded_randomness: 38 callbacks suppressed
[   38.624389] random: get_random_u64 called from
dup_task_struct+0x415/0xa10 with crng_init=0
Begin: Running /scripts/local-block ... [   38.630760] random:
get_random_u64 called from arch_pick_mmap_layout+0x410
[   38.630767] random: get_random_u64 called from
arch_pick_mmap_layout+0x381/0x5e0 with crng_init=0
mdadm: No arrays found in config file or automatically
done.
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
[   39.633914] _warn_unseeded_randomness: 1278 callbacks suppressed
[   39.633918] random: get_random_u64 called from
dup_task_struct+0x415/0xa10 with crng_init=0
[   39.634867] random: get_random_u64 called from
arch_pick_mmap_layout+0x411/0x5e0 with crng_init=0
[   39.634875] random: get_random_u64 called from
arch_pick_mmap_layout+0x381/0x5e0 with crng_init=0
mdadm: error opening /dev/md?*: No such file or directory
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
mdadm: No arrays found in config file or automatically
done.
Gave up waiting for root file system device.  Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enough?)
 - Missing modules (cat /proc/modules; ls /dev)
ALERT!  UUID=3caf26b5-4d08-43e0-8634-7573269c4f70 does not exist.
Dropping to a shell!

Any suggestions? Thanks.

--
Haiwei