Commit dc8ea871 authored by Teddy Astie's avatar Teddy Astie Committed by Juergen Gross
Browse files

xen/virtio: Don't use grant-dma-ops when running as Dom0 



Dom0 inherit devices from the machine and is usually in PV mode.
If we are running in a virtual that has virtio devices, these devices
would be considered as using grants with Dom0 as backend, while being
the said Dom0 itself, while we want to use these devices like regular
PCI devices.

Fix this by preventing grant-dma-ops from being used when running as Dom0
(initial domain). We still keep the device-tree logic as-is.

Signed-off-by: default avatarTeddy Astie <teddy.astie@vates.tech>
Fixes: 61367688 ("xen/virtio: enable grant based virtio on x86")
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Message-ID: <6698564dd2270a9f7377b78ebfb20cb425cabbe8.1767720955.git.teddy.astie@vates.tech>
parent db9aded9

drivers/xen/grant-dma-ops.c

+2 −1
Original line number Diff line number Diff line
@@ -366,7 +366,8 @@ static int xen_grant_init_backend_domid(struct device *dev, 
	if (np) {

		ret = xen_dt_grant_init_backend_domid(dev, np, backend_domid);

		of_node_put(np);

	} else if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT) || xen_pv_domain()) {

	} else if (!xen_initial_domain() &&

		   (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT) || xen_pv_domain())) {

		dev_info(dev, "Using dom0 as backend\n");

		*backend_domid = 0;

		ret = 0;