Commit 988f0e24 authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk

xen/swiotlb: Simplify the logic.

Its pretty easy:
 1). We only check to see if we need Xen SWIOTLB for PV guests.
 2). If swiotlb=force or iommu=soft is set, then Xen SWIOTLB will
     be enabled.
 3). If it is an initial domain, then Xen SWIOTLB will be enabled.
 4). Native SWIOTLB must be disabled for PV guests.
Acked-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 28a33cbc
......@@ -34,18 +34,19 @@ static struct dma_map_ops xen_swiotlb_dma_ops = {
int __init pci_xen_swiotlb_detect(void)
{
if (!xen_pv_domain())
return 0;
/* If running as PV guest, either iommu=soft, or swiotlb=force will
* activate this IOMMU. If running as PV privileged, activate it
* irregardless.
*/
if ((xen_initial_domain() || swiotlb || swiotlb_force) &&
(xen_pv_domain()))
if ((xen_initial_domain() || swiotlb || swiotlb_force))
xen_swiotlb = 1;
/* If we are running under Xen, we MUST disable the native SWIOTLB.
* Don't worry about swiotlb_force flag activating the native, as
* the 'swiotlb' flag is the only one turning it on. */
if (xen_pv_domain())
swiotlb = 0;
return xen_swiotlb;
......
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