On Wed, May 11, 2022 at 10:10:40AM +0000, Conor.Dooley@xxxxxxxxxxxxx wrote: > Without even trying the patch, I double checked the boot log from > 3f70356edf56 and I get a "software IO TLB: Cannot allocate buffer" > With the patch its a "software IO TLB: swiotlb_init_remap: failed > to allocate tlb structure". So spot on & I feel like an idiot for > not spotting that before! > > Is failing being fatal valid, or should it fail gracefully like it > used to do? To me, blissfully unaware about swiotlb, the "current" > behaviour of failing gracefully makes more sense. Given that we're at -rc6 I think the most important thing for now is to avoid a regression and restore the old behavior. I'll send out a series with this and the nslab related fixes for Xen today. But we should look into why allocating the memory fails for your plaforms. Does it have very little memory? I can't really think of why else the memblock allocation for swiotlb would fail.