On Fri, 23 Jul 2021 20:27:56 -0400 Konrad Rzeszutek Wilk <konrad@xxxxxxxxxx> wrote: > On Sat, Jul 24, 2021 at 01:17:46AM +0200, Halil Pasic wrote: > > Since commit 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for > > swiotlb data bouncing") if code sets swiotlb_force it needs to do so > > before the swiotlb is initialised. Otherwise > > io_tlb_default_mem->force_bounce will not get set to true, and devices > > that use (the default) swiotlb will not bounce despite switolb_force > > having the value of SWIOTLB_FORCE. > > > > Let us restore swiotlb functionality for PV by fulfilling this new > > requirement. > > > > This change addresses what turned out to be a fragility in > > commit 64e1f0c531d1 ("s390/mm: force swiotlb for protected > > virtualization"), which ain't exactly broken in its original context, > > but could give us some more headache if people backport the broken > > change and forget this fix. > > > > Signed-off-by: Halil Pasic <pasic@xxxxxxxxxxxxx> > > Tested-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > > Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > > Fixes: 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing") > > Fixes: 64e1f0c531d1 ("s390/mm: force swiotlb for protected virtualization") > > Cc: stable@xxxxxxxxxxxxxxx #5.3+ > > > > --- > > Picked it up and stuck it in linux-next with the other set of patches (Will's fixes). Thanks!