Re: [PATCH] xen: don't require virtio with grants for non-PV guests

From: Oleksandr
Date: Wed Jun 15 2022 - 11:48:05 EST



On 15.06.22 11:48, Juergen Gross wrote:

Hello Juergen

Commit fa1f57421e0b ("xen/virtio: Enable restricted memory access using
Xen grant mappings") introduced a new requirement for using virtio
devices: the backend now needs to support the VIRTIO_F_ACCESS_PLATFORM
feature.

This is an undue requirement for non-PV guests, as those can be operated
with existing backends without any problem, as long as those backends
are running in dom0.

Per default allow virtio devices without grant support for non-PV
guests.

The setting can be overridden by using the new "xen_virtio_grant"
command line parameter.

Add a new config item to always force use of grants for virtio.

Fixes: fa1f57421e0b ("xen/virtio: Enable restricted memory access using Xen grant mappings")
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Thank you for the fix.


I have tested it on Arm64 guest (XEN_HVM_DOMAIN), it works.

With the "__init" fix (pointed out by Viresh) applied you can add my:

Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx> #Arm64 only


[snip]


--
Regards,

Oleksandr Tyshchenko